Health Policy Research Bulletin
Volume 1, Issue 4
Over the years, public health and environmental policies aimed
at reducing environment-related disease have contributed to significant
improvements in the health status of Canadians. Despite these advances,
however, health problems as a result of exposure to environmental
contaminants remain a serious concern for many Canadians. This is
especially true for certain populations who, because of their stage
of physical development, or their living and working conditions,
are at greater risk than the general population. A growing concern
for many Canadians is the cumulative effect of long-term exposure
to low doses of environmental contaminants.
While "the environment" in its broadest sense has important
influences on human health, this issue of the Health Policy Research
Bulletin focuses on the health impacts of the "physical
environment." More specifically, it explores the range of research
and evidence required to effectively assess and manage environmental
health risks including, for example:
- developing environmental health indicators and ensuring that
stappropriate surveillance systems are in place
- identifying potential environmental threats and assessing the
associated health risks
- determining the pathways and mechanisms of exposure and identifying
potential points for intervention
Depending upon the evidence, options for managing the risks associated
with potential environmental threats may vary from minimum-level
interventions (e.g., increasing public awareness) to maximum-level
interventions (e.g., legislation banning the release of a substance
into the environment). A case study on developing regulations aimed
at limiting the sulphur content in gasoline provides a good illustration
of how research can be used to help manage environmental health
risks.
Health and the Environment
A Policy Nexus
Healthy Environments, Healthy People
Measuring the Impact
Populations and Pathways
Living Conditions and Disease
Taking Action on Vehicle Emissions
About Health Surveillance
Understanding Statistical Significance
Mark Your Calendar
Our mission is to help the people of Canada maintain
and improve their health.
Health Canada
About the Health Policy Research Bulletin
Health Canada's Health Policy Research Bulletin is published three
times a year. The Bulletin is part of a larger policy research dissemination
program designed to enhance Health Canada's policy-relevant evidence
base.
A departmental steering committee guides the development of the
Bulletin. The committee is chaired by Cliff Halliwell, Director
General of the Applied Research and Analysis Directorate (ARAD)
of the Information, Analysis and Connectivity Branch. The Research
Management and Dissemination Division (RMDD)
within ARAD
coordinates the Bulletin's development and production. RMDD
would like to thank the steering committee members for their contributions,
as well as Nancy Hamilton and Linda Senzilet, Managing Editors,
Jaylyn Wong, Assistant Editor, and Marilyn Ryan, Production and
Distribution. Special thanks go to the Guest Editor of this issue,
Ray Edwards, Director General of the Policy and Planning Directorate,
Healthy Environments and Consumer Safety Branch.
We welcome your feedback and suggestions. Please forward your comments
and any address changes to bulletininfo@hc-sc.gc.ca
or phone (613) 954-8549 or fax (613) 954-0813. Electronic HTML and
PDF versions of the Bulletin are available at: http://www.hc-sc.gc.ca/iacb-dgiac/arad-draa/english/rmdd/bulletin/bulletin.html
Health Policy Research Bulletin
The opinions expressed in these articles, including interpretation
of the data, are those of the authors and are not to be taken as
official statements of Health Canada.
This publication can be made available in alternative formats upon
request.
Permission is granted for non-commercial reproduction provided
there is a clear acknowledgment of the source.
Published under the authority of the Minister of Health.
© Her Majesty the Queen in Right of Canada, represented by
the Minister of Public Works and Government Services Canada, 2002
ISSN 1496-466 X ISSN 1499-3503 (Online)
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Environmental Health Legislation
Health Canada is involved in administering, in whole or in part,
20 pieces of health-related legislation. An overview of some of
the key legislation aimed at protecting and promoting environmental
health is provided below. A more complete list of relevant legislation
can be found at:
http://www.hc-sc.gc.ca/english/about/acts_regulations.html
Responsibility of Environment Canada and Health Canada
- Canadian Environmental Protection Act (CEPA):
governs pollution prevention and protection of the environment
and human health, all within the context of sustainable development
goals
Responsibility of Health Canada
- Hazardous Products Act (HPA):
prohibits the advertising, sale and importation of hazardous products
- Food and Drugs Act (FDA):
ensures the safety of food, drugs, cosmetics and therapeutic devices
- Pest Control Products Act (PCPA):
governs the importation, manufacture, sale and use of pesticides
Responsibility of Environment Canada
- Canadian Environmental Assessment Act (CEAA):
ensures all new projects with federal involvement include an environmental
impact assessment, including an assessment of human health impacts
Health and Environment: A Policy Nexus
The following article is based on an interview with Rod Raphael,
Director General of the Safe Environments Programme, Healthy Environments
and Consumer Safety Branch, Health Canada. The interview was conducted
by Nancy Hamilton, a Managing Editor of the Health Policy Research
Bulletin.
This
issue of the Bulletin examines the relationship between two important
areas - health and the environment. What is a good starting point
for understanding this relationship?
Health and the environment are two very important, intertwined areas
of policy. From a health policy perspective, our starting point
is a recognition that the "environment" is one of several
determinants of health. Our health - in fact, our very survival
- depends on the environment, from the air we breathe, to the water
we drink and the food we eat. When any of these is threatened, human
health is compromised. This is the starting point from which health
departments work to identify, reduce and prevent environment-related
health risks.
When you say that the environment is a determinant of health,
how would you define "environment?"
In its broadest sense, environment refers to the physical, social,
cultural and economic attributes of our surroundings. While all
of these have important influences on human health, the "physical
environment" has been identified within the determinants of
health model as one of 12 interrelated health determinants. So,
for our discussions here, we'll focus on the impacts of the physical
environment on human health. However, regardless of what we understand
the environment to be - air, water, soil, trees, the biota and so
on - human health depends on a well-functioning environment and
harmonized ecosystems.
Recognizing
that the physical environment is a determinant of health, in what
ways does it affect our health?
The physical environment can influence our health through the direct
impacts of naturally occurring substances within the environment
and also as a consequence of our individual and collective interactions
with the environment. As a society, we use the natural resources
within our environment for purposes of economic and social development.
Consequently, we have to consider the primary, secondary and tertiary
impacts of development on human health, most of which stem from
- in the terminology of the '80s and '90s - a polluted environment.
How
can we measure the impact of the environment on human health?
Being able to measure the impact of the environment on human health
is an important public policy challenge and one that requires a
much greater investment than we have given it so far. We need to
understand the risks and benefits associated with various courses
of action so we can make policy decisions that favour human health.
One way to do this is to identify variables/indicators or proxy
variables/indicators that can help us understand how human health
and systems are affected by our interactions with the environment.
We've made progress in some areas. For example, with respect to
the relationship between air quality and cardiorespiratory diseases,
we've been able to measure trends using some rough indicators of
illness and disease, including mortality and morbidity analyses
(see article on page 9). But, we have a long
way to go! We often focus on acute situations and fail to recognize
the underlying chronic dimensions that must be taken into account.
How can research inform policy development with respect to health
and the environment?
Policy development in the area of health and the environment is
evidence-based. We use the scientific method to understand the ecological
processes that are being disturbed and the actions that can be taken
to prevent or mitigate their impacts or to avoid them in the first
place. This is a monumental research effort involving scientists
in Health Canada and other government departments, as well as those
in academic institutions and private corporations.
A critical issue relates to the precautionary principle and the
role that research plays in the development of public policy. Applying
the precautionary principle within a risk management framework
means that, in situations where serious or irreversible health threats
exist, action is justified even in the absence of full scientific
certainty. For example, in the area of children's environmental
health, we may not know all of the pathways by which environmental
factors affect the developing physiology of a child, and yet we
make decisions to act based on rudimentary information with the
belief that society expects us to protect children's health from
environmental insults. It's important to remember that the availability
of evidence is not the sole determinant of policy action. Social
values also play an important role.
What is the current status of the evidence base on the effects
of the physical environment on human health?
While we've made progress, the evidence base in many areas is still
fairly new, especially with respect to the cumulative effects of
long-term exposure to environmental change. For example, an evidence
base is only now emerging about the endocrine-disrupting effects
of chemicals that have entered the environment as a result of 20th
century development (see article on page 5).
In other areas, the evidence base is more mature. For example, we
know there is tremendous diversity within the human population,
including an underlying genetic diversity that can lead to predispositions
to certain types of reactions to environmental factors. Consequently,
some people are more sensitive than others to factors within the
environment. It is also clear that we go through phases of heightened
sensitivity during our lives, from early childhood through to adolescence,
during pregnancy and as we age (see article on
page 13).
There is also a growing body of research exploring the pathways
of exposure by which the environment-health link works. We know,
for example, that one's health risk to a substance in the environment
depends on more than individual sensitivity; it depends on how concentrated
the substance is and the pathways or mechanisms of exposure. Understanding
such pathways is critical to eliminate or control the associated
health risks.
As a result of exciting developments in an area that might be called
"molecular epidemiology," we're beginning to understand
more about the subtle, but long-lasting effects at the level of
the genome. While evidence of these chronic, potentially cross-generational
impacts is building, it is not at the same level as evidence of
acute impacts of short-acting toxic materials. Nevertheless, improved
surveillance techniques at the population level and our growing
capacity to analyze surveillance data at the molecular level are
contributing to a rapidly growing evidence base in this promising
new area.
Healthy Environments, Healthy People
Anthony W. Myres, PhD, Safe Environments Programme, Healthy Environments
and Consumer Safety Branch, Health Canada, and Katherine Betke,
School of Applied Biology (Co-op Program), University of Victoria
In this overview of the link between the environment and health,
the authors focus on the role of the physical environment as a determinant
of health. They trace the evolution of knowledge about how elements
of the physical environment affect health and introduce some key
considerations in assessing and managing environmental health risks.
The Environment - A Determinant of Health
"The environment is everything that isn't me." (Einstein)
This statement not only underscores how pervasive "the environment"
actually is, it also alludes to the difficulty of establishing causal
links between specific elements in the environment and their impact
on health. According to the Canadian Environmental Protection
Act (CEPA),
the federal government's key environmental protection legislation,
the environment includes ". . . the components of the Earth,
including: the air, land and water; all layers of the atmosphere;
all organic and inorganic matter and living organisms; and the interacting
natural systems that include components referred to in the latter."1
From a human health perspective, the term environmental health
is even broader, encompassing all aspects of human health, disease
and injury that are determined by factors in the environment. These
factors include the direct pathological effects of chemical, physical
and biological agents, as well as the health effects of the broad
physical and social environment (e.g., housing, urban development,
land use and transportation, industry and agriculture).2
This concept of environmental health - as established by the World
Health Organization (WHO)
- is illustrated in Figure 1.
The concept of health has also expanded over the years,
beginning with the WHO's
1948 assertion that "health is not merely the absence of disease
but a state of complete mental, physical, emotional and spiritual
well-being." A significant break with past thinking, this broader
understanding of health continued to evolve, first making inroads
in Canada with the publication of A New Perspective on the Health
of Canadians.3 This report marked the first
time a major government document acknowledged that the influences
on health extended beyond health care to include human biology (genetic
factors), living habits (lifestyle) and the environment.
The Changing Nature of Environment-Related Disease
While a holistic approach to public health may be relatively new,
the connection between health and the environment - in the narrower
sense of clean air and water, and safe and nutritious food - has
long been known. Advances in these areas have been largely responsible
for the significant improvements in public health in Canada over
the past century. However, many of these environmental health concerns
are still serious problems among Canada's First Nation communities
(see article on page 15).
Despite recent advances, Canadians are worried about the impact
of the environment on their health. One of the main reasons is the
perception that environmental health problems are increasing and
adversely affecting their health now. Almost two thirds of Canadians
believe their health is affected by the environment, and a similar
proportion view environmental pollution as posing the greatest threat
to future generations (compared to 9 percent who viewed "wars
and conflict" as the greatest threat).4
This raises an interesting paradox since, by all the established
measures of public health (e.g., infant morality, life expectancy),
Canadians have never been healthier. Yet, serious problems remain.
For example, the incidence of children's asthma, which is certainly
exacerbated by poor air quality, has increased fourfold since the
1970s.5
The Chemical Revolution
One growing environmental concern is the proliferating use of chemicals
in industry, agriculture and consumer products - a chemical revolution
that is said to rival the significance of the Industrial Revolution.
While many industrialized societies now depend on chemicals to maintain
their standard of living, there are increasing concerns about related
health hazards, particularly long-term exposure to low levels of
chemicals and the adverse effects on the developing foetus, infant
and young child (see article on page 13).
The 1962 publication of Rachel Carson's Silent Spring first
drew public attention to environmental pollution caused by the indiscriminate
use of pesticides.6 This work and the later environmental
movements it spawned, helped galvanize governments in Canada and
the United States to establish departments of the environment and
to enact legislation to protect the environment.
The Federal Response
Environmental legislation in Canada is a shared responsibility
between the Ministers of the environment and health, with the Environment
Minister maintaining overall administrative responsibility. The
country's first environmental protection legislation was the 1974
Environmental Contaminants Act, a forerunner to the more
comprehensive Canadian Environmental Protection Act (CEPA),
1988, which was significantly amended in 1999. Under CEPA,
the government has successfully put into place controls on environmental
hazards - for example, phasing out the use of ozone-depleting substances,
the emission of dioxins and furans from pulp mills using chlorine
bleaching and the use of lead and sulphur in gasoline (see
article on page 19).
As outlined on page 2, Health Canada has additional
responsibility for a wide range of legislation designed to protect
and promote the health of Canadians. Four of these Acts are of particular
importance for protecting public health from chemical risks, either
by controlling the level of hazardous substances in a product, or
by controlling substance emissions at their source.
Sustainable Development: Linking Environment, Health and Economy
The link between health, the environment and the economy came into
international focus in 1987 when the Bruntland Commission defined
sustainable development as "that which meets the needs of today
without compromising the ability of future generations to meet their
own needs."7 In 1995, the federal government
officially adopted both pollution prevention and sustainable development
as elements of its policy agenda. By 1997, all federal departments
were required to develop and implement sustainable development action
plans demonstrating the social, economic and environmental factors
taken into consideration in their decision making.8
An overarching federal strategy on sustainable development is currently
in development.
Risk Assessment and Risk Management
"There is no safety without risk." (Wildavsky)
Recognizing that a completely risk-free environment is not an achievable
goal, governments need a systematic decision-making process to determine
the level of risk that is acceptable both to the environment and
to public health. A number of frameworks have been designed over
the years, all of which include the following core steps: identify
the hazard; characterize and quantify the risk; develop options
for controlling the risk; implement the control measures (risk management);
and evaluate. Health Canada's current approach to decision making
incorporates these steps.9 It should be noted that,
although this decision-making process appears simple, it includes
a number of important constraints, such as the need to:10,11
- extrapolate from evidence derived at high doses to determine
risk at lower doses
- extrapolate from animal data to human risk and from past or
current data to future generationsllow for the effects of exposure
to complex mixtures of chemicals and their interactions
- define and value the quality of life
The Role of Science
"When you cannot measure it . . . your knowledge is of
a meagre and unsatisfactory kind." (Lord Kelvin)
The goal of hazard identification, risk assessment and risk management
is to identify a course of action that is not only scientifically
sound, but also cost effective and integrated. In other words, risks
are reduced while taking into account key social, cultural, ethical,
political, economic and legal considerations. Although scientific
input is important, establishing an unequivocal cause- effect relationship
is a long and difficult process, and there are always uncertainties.
As a result, discussions of environmental and health protection
over the past quarter century have given increasing attention to
an approach that is guided by the "precautionary principle."
The most widely-accepted definition of the precautionary principle
is one endorsed at the Earth Summit in Rio in 1992. The Rio Declaration
states that: "Where there are threats of serious or irreversible
damage, lack of full scientific certainty shall not be used as a
reason for postponing cost-effective measures to prevent environmental
degradation." The CEPA
has adopted this definition and it is now the explicit duty of the
Government of Canada to implement the principle.
Similarly, Health Canada's first Sustainable Development Strategy
recognizes the need to apply the precautionary principle as a means
of preventing serious and irreversible impacts on human health.8
This does not mean taking action in the absence of evidence but,
rather, ensuring that the quality and the weight of the evidence
is taken into account even though it falls short of scientific "proof."
Nor does it mean automatically assuming the "worst case"
scenario, an approach that may result in inefficiencies or wasting
scarce resources that might otherwise be used to address more pressing
problems.
Clearly, it is possible for people to become exposed to any substance
in the environment. The question is: "What is the risk that
exposure will cause harm?" (risk assessment). The corollary
is: "What can be done about it?" (risk management). The
harm that is done to human health is a function of the inherent
toxicity (hazard) and the degree of exposure (i.e., the concentration
or dose and the length of time exposed).
Hazard is a property of the chemical or substance, susceptibility
is a property of the organism being affected by the chemical (in
this case, human beings) and exposure is a property of the
intervening environment (i.e., the environment, from the point where
the chemical is released and along its pathway to humans). Risk
is a measure of both the hazard and the probability of its occurrence
(see Figure 2). To illustrate, consider crossing
the ocean in a boat - either an ocean liner or a row boat. The hazard
(of drowning) remains the same, but the risk is considerably reduced
in an ocean liner because the probability of exposure, compared
to a row boat, is minimal.
Over 400 years ago, Paracelsus observed: "All things are poisons,
for there is nothing without poisonous qualities. It is only the
dose that makes a thing a poison." This presents a profound
truth - overexposure to any substance can threaten health. Because
the level of harm depends on the level of exposure, it is a continuing
challenge to determine through risk assessment the level
of exposure to particular substances - including food, water, air
and consumer products - that will result in increased risks to health.
Risk management options cover the full spectrum, from minimal
intervention (e.g., enhancing public awareness) to maximum intervention
(e.g., a ban).
Future Challenges - Finding the Right Balance
Science will continue to play the primary role in establishing
the evidence base for decision making, particularly with respect
to identifying environmental hazards and their links to health outcomes.
Together with Health Canada, the Canadian Institutes of Health Research
(CIHR)
is taking a leadership role in developing a national research agenda
on the environmental influences on health that is aimed at strengthening
the research base over the next 10 to 15 years. However, the need
for additional research does not necessarily mean postponing action.
The British medical statistician, Sir Austin Bradford Hill,12
who wrote a classic text on causality and disease, highlights the
challenge of achieving an appropriate balance:
"All scientific work is incomplete. All scientific work is
liable to be upset or modified by advancing knowledge. That does
not confer upon us a freedom to ignore the knowledge we already
have, or to postpone the action that it appears to demand at a given
time."
Environmental Health Indicators
Sabit Cakmak and Sheryl Bartlett, Safe Environments Programme,
Healthy Environments and Consumer Safety Branch, Health Canada,
and Paul Samson, recently with Environment Canada
Environmental Health Indicators (EHIs)
are important tools for assessing the impact of environmental factors
on human health. Health Canada is currently collaborating with other
federal departments to develop a set of EHIs
for use in Canada. This article examines the need for such indicators
and presents a framework for navigating the complexities of the
indicator development process.
Introduction
Individuals, corporations and governments have come to rely on
economic indicators such as the Gross Domestic Product (GDP),
the inflation rate and the unemployment rate to help guide their
decision making. Spurred by the widespread use of such economic
indicators, international organizations and governments at various
levels have initiated a range of projects focussing on the development
of indicators in the social and environmental fields (see
also "Who's Doing What?" on page 23). To ensure that
these new indicators serve the varied needs of researchers and policy
makers, they must meet a number of important criteria.
What are Indicators?
Environmental indicators are important measures of phenomena that
may pose a threat to the natural environment as well as to living
organisms. Environment Canada's Indicators and Assessment Office
defines indicators as statistics or parameters that, tracked
over time, provide information on trends in the condition of a phenomenon.
Environmental indicators are key statistics that represent
or summarize a significant aspect of the state of the environment.
They focus on trends in environmental changes, as well as on the
stresses causing these trends, how the ecosystem and its components
are responding to the changes, and what society is doing to prevent,
reduce or ameliorate the stresses. A significant challenge in developing
useful environmental indicators lies in achieving a balance between
scientific accuracy and simplicity. Often, the difficulty lies in
aggregating complex data into simple summary indicators, particularly
if there is no overarching conceptual framework governing the relevant
indicators. Environmental indicators like the Air Quality Index
(AQI) in the box on
page 10 provide only indications of health
risks, as no direct links between indicators and health have been
established. Therefore, environmental health indicators (EHIs)
are being developed to measure the relationship between the environment
and health.
An Environmental Indicator
The Air Quality Index (AQI),
which relates pollutants to National Ambient Air Quality Objectives
(NAAQO),
is an example of an environmental indicator that strives to achieve
a balance between scientific accuracy and simplicity. The AQI
is based on measures of pollutants that have adverse effects on
human health and the environment, including sulphur dioxide, nitrogen
dioxide, ozone, total reduced sulphur compounds, carbon monoxide
and suspended particles measured as the coefficient of haze. Every
hour, the concentration of each of these pollutants at a particular
site is converted to a number on a common scale or index. The value
for each pollutant is called a sub-index and the pollutant with
the highest value determines the AQI
for that time period, at that site. The lower the AQI,
the better the air quality.
EHIs:
Indicators of a Relationship
Environmental health indicators are measures of health status
attributable to the physical environment. Because people can relate
to many of them (e.g., indicators of mortality, disability), EHIs
are often better understood than environmental indicators. EHIs
are also more amenable to aggregation because established methodologies
exist for weighting different health states (e.g., losing lung capacity
versus getting cancer). As well, EHIs
serve as useful adjuncts to environmental indicators, as they can
provide "macro" corroborating (or not) evidence about
environmental developments - for example, air quality is improving
and air quality-related health problems are diminishing.
Air pollution is an example of an environmental problem that has
been identified as having health consequences. Bell and Davis1
recently reassessed data on the health consequences of a lethal
fog episode during the winter of 1952 in London, England. They estimated
that 12,000 deaths occurring from December 1952 through February
1953 were due to acute and persisting effects of smog (Figure
1 shows the effect of pollution on mortality during December
1952). Air pollution levels for the period were 5 to 19 times above
current (i.e., 2002) regulatory standards and guidelines, as well
as levels in some rapidly developing regions of the world.1
Since that study, similar associations have been found in studies
of other metropolitan areas - for example, ambient levels of particulate
matter have been linked to daily mortality rates for the period
1986-94 in Toronto, Canada (see Figure 2).
How Are EHIs
Developed?
In developing EHIs,
consideration must be given to the nature of the relationship between
a factor in the environment and its impact on health. In this regard,
an analytical framework is essential in classifying EHIs
along the cause-effect continuum.
Frameworks: A Necessary Starting Point
In designing EHIs,
a major concern is the ability to link the impact of the environment
to health status, ideally as a cause-effect relationship. Unlike
the above examples, however, information may be available on either
exposure or health status, but not on both. In addition, the links
between exposure and health status may be tenuous and, as a result,
findings must reflect this uncertainty. For these reasons, it is
important to use an analytical framework in developing EHIs,
so that indicators may be classified along the cause-effect continuum.
Several such frameworks have been proposed, most of which are derived
from the Pressure-State-Response (PSR)
framework. For example, the World Health Organization (WHO)
has expanded the PSR
framework to capture the crucial linkages involved in assessing
environmental health. The resulting approach, entitled the Driving
Forces, Pressure, State, Exposure, Effects, Action (DPSEEA)
model, provides a broad starting point from which a set of specifically
tailored national indicators can be developed.2
While the model offers a "big picture view," it also focuses
attention on individual components - state, exposure
and effects - that are key to determining the environment-health
relationship.
The issue of air quality illustrates how the DPSEEA
Framework and its elements were used to construct an EHI
linking air quality and health. Following are the "core"
indicators representing the respective elements of the framework
as they relate to air quality:
- urban density/sprawl and the volume and type of road traffic
(driving forces)
- emissions of air pollutants (pressure)
- ambient concentrations of air pollution, i.e, concentration
of PM2.5, PM10, ozone, etc. (state)
- population exposure to pollution in excess of maximum acceptable
levels (exposure)
- population mortality/morbidity due to respiratory or cardiorespiratory
disease (effect)
- agreements, initiatives, and programs (action)
Choosing Themes and Issues
EHIs
are currently being developed on the following broad themes: air
and atmosphere; water and aquatic systems; land and land cover;
and food and food products. While EHIs
are useful to consider on their own, they are only one part of the
broader picture of sustainable development. To be effective, indicators
need to: be built around clear, specific goals; consider the ambient
physical and social environment; and be embedded within a sustainable
development context.3
Criteria for Selecting Indicators
Much has been written about the criteria for selecting indicators.
For example, the OECD's
foundation work on indicators4 discusses both
technical/scientific and user/policy elements as criteria.
Scientific-based criteria include data availability
and sustainability, validity, representativeness, reliability and
the ability to be broken down into other variables. User-based
criteria for indicators include the feasibility of access
and the relevance of the indicator to those affected. Indicators
should also be scientifically sound, robust, easily understood,
sensitive to the changes they are meant to represent, measurable
and capable of being updated regularly.5
An Example of an EHI:
Making the Air Quality-Health Link
The primary motivation for reducing air pollutant levels is to
protect population health. However, the Air Quality Index (AQI)
cannot actually tell the magnitude of the impact of exposure to
air pollutants on health. Burnett et al.6 have
proposed an environmental health indicator that makes a direct link
between air quality and health. This indicator measures improvements
in population health, based on reductions in ambient fine particulate
matter over time. It is a function of several factors - including
temporal changes in site-specific ambient concentrations and the
relationship between those concentrations and daily mortality or
hospital admissions rates for heart and lung problems. The new indicator,
which is based on a methodology used in a number of epidemiological
studies, can be determined for a single location, or at the regional
or national level, and can also be expanded to include several pollutants.
It is even possible to extend the methodology so that the annual
number of deaths attributed to fine particulate exposures can be
tracked over time across Canada.
EHIs:
How Can We Use Them?
The potential negative impact of the environment on human health
has long been a policy concern. There is widespread agreement that
access to valid and relevant information about local and national
health impacts of environmental hazards is key to developing and
monitoring policy in this area. EHIs
offer a concise, effective and easily understood way of making such
information available to public health agencies, decision makers
and health professionals. Within this context, EHIs
serve an important function in several key areas:
Identification of hazards/risks: EHIs
can be used to monitor environmental health hazards, thereby helping
to identify and investigate potential links between environmental
factors and health effects.
Decision making and policy development: EHIs
can provide input into the decision-making process by monitoring
health trends in the context of environmental exposure and risk
factors.
Setting and evaluating program objectives: Specific
EHIs
can be used to set program objectives that can then be tracked and
re-evaluated over time - these performance measures can help in
assessing the effects of various policies and interventions.
Accountability and environmental health reporting:
Federal departments and agencies play an important role in providing
information to Parliament and Canadians. In the past, performance
measurements have been based largely on subjective assessments rather
than on objective measures of the outcomes of various actions. Indicators
provide a level of transparency in environmental reporting that
was not previously possible.
Moving Forward
Environmental health indicators show significant promise as a means
of credibly and transparently connecting science and policy. However,
complex environmental health issues may require aggregating sets
of indicators into indices. Researchers will need to respond to
these needs by moving a step further to develop easily understandable
indices for use in decision making by government policy makers,
business leaders and members of the public.
Vulnerable Populations: Critical Pathways
Anthony W. Myres, PhD, Safe Environments Programme, Healthy Environments
and Consumer Safety Branch, Health Canada
In assessing environmental risks to health, it is important to
recognize that people are not all alike, either in their level of
exposure or their ability to detoxify. While the goal of public
health is to protect the health of all, some subpopulations may
be more at risk than others. Understanding the impact of environmental
hazards on specific populations can result in concrete steps towards
identifying, preventing, reducing and eliminating various health
risks.
In Northern Communities
Many people living in the Canadian Arctic rely on a diet comprised
primarily of fish and wild game. As a result, they may be exposed
to relatively high levels of contamination, due to a cumulative
buildup of contaminants higher in the food chain. The Northern Contaminants
Program (NCP),
which operates under the aegis of Indian and Northern Affairs Canada,
addresses the issue of food contamination in northern diets. One
of the principal tenets of the NCP
is that risks must be balanced against benefits. Within this context,
the current consensus is that the known nutritional, social and
cultural benefits of consuming "country foods" (i.e.,
from fish and wildlife harvesting) outweigh the health risks of
contaminants in these foods.1 Health Canada plays
a lead role in the NCP's
health program.
A number of other environmental issues have particular implications
for people living in Canada's North. For example, the Arctic climate
acts as a condenser, creating a "sink" for pollutants
such as Persistent Organic Pollutants (POPs
- e.g., DDT, PCBs) that are conveyed by long-range transport. To
address this issue, Canada played a lead role in developing the
UN Convention on Persistent
Organic Pollutants and was the first country to ratify the Convention.2
Throughout the Life Cycle
Research has also shown evidence of heightened sensitivity to environmental
hazards at certain stages of human development:
Infancy and Childhood
Because their tissues and organs are undergoing rapid cellular
development, infants and very young children are more vulnerable
than adults to environmental hazards.3 While there
is some debate about whether children are always more susceptible
to chemical toxicity than adults,4 there is no
doubt that infants have unique characteristics (metabolism, exposure
patterns, behavioural features) and cannot be considered simply
as "little adults."5 Breast milk is
one pathway through which children are exposed to environmental
contaminants. As some contaminants can build up in breast milk (from
those stored in the mother's fat deposits), breastfed infants may
be exposed to high doses of contamination. However, the unique benefits
of breastfeeding - nutritional, immunological, psychological and
emotional - far outweigh the risks from contaminants, a conclusion
that has been endorsed by health professionals and governments worldwide.6
Many of the major disorders confronting Canadian children today
are chronic, disabling conditions sometimes referred to as the "new
pediatric morbidity." Besides injuries and obesity, the new
pediatric morbidity includes increases in asthma, disorders of endocrine
and reproductive development and neurodevelopmental dysfunction.
Evidence shows that chemicals in the environment may be contributing
factors to these conditions.7 Because healthy
early child development is a prime determinant of later health,
there has been an enormous international effort to make children's
environmental health a priority.8-9-10-11-12
Adolescence
Adolescence is another "window of vulnerability," due
to the rapid growth rate and the surge of hormones related to sexual
development. Of particular concern are endocrine-disrupting substances
(EDS),
including a variety of organic and inorganic pollutants, that have
the potential to interfere with hormones controlling growth, development,
reproduction and the function of the immune and central nervous
systems. While there is no conclusive evidence of human health risks
due to current levels of EDS
exposure, adverse effects have been documented in fish and wildlife,
as well as on laboratory animals. Studies such as these suggest
a number of possible effects on human health, including earlier
onset of puberty, altered development of male and female reproductive
tracts and reduced sperm production.13-14-15
Animal studies indicate that these effects are likely a consequence
of earlier, possibly in utero, exposure.
The Reproductive Years
Environmental hazards can also affect fertility and pregnancy outcomes,
as measured by rates of infertility, spontaneous abortion, chromosomal
anomalies, pre-term delivery, low birthweight and stillbirths. Low
dosage exposure of pregnant women to some toxic substances may affect
neurophysiological and other facets of fetal development at critical
stages, resulting in later learning disorders or other conditions.16
Very little research has been done on the sex/gender-specific effects
of exposures to toxicants such as pesticides and metals.17
However, men and women are known to have different vulnerabilities
to the effects of EDS.
For women, these may be related to a higher proportion of fatty
tissue, and to hormone-regulated cycles and processes of menstruation,
pregnancy and menopause. In men, EDS
exposure may contribute to "male reproductive syndrome,"
as manifested in lower sperm counts, reproductive birth anomalies
and testicular cancer.18 It appears likely that
such clinical outcomes are due to events occurring very early in
development.19,20
The Senior Years
Over the past century, medical science has made it possible for
people to live much longer. Ironically, longer life also means greater
exposure to the harmful effects of the environment. As a result,
seniors face particular health risks, not only due to the cumulative
effect of environmental hazards, but also to the declining "margin
of safety" in key organ systems such as the cardiorespiratory
and immune systems, and to the presence of pre-existing health conditions.
The effects of this combination of age and disease-related risks
are particularly evident in seniors' greater susceptibility to air
pollution. Aging commonly reduces a person's "maximum oxygen
uptake," with the result that seniors can find it difficult
to meet their daily oxygen requirements.21 In
such cases, even low levels of pollutants can have a critical effect.
Research also shows that the prevalence of chronic obstructive pulmonary
disease (COPD)
increases with age;22 lungs and airways that are
compromised by COPD
are more susceptible to the effects of both indoor and outdoor air
pollution.
A special thanks to the following people for their input into this
article: Sari Tudiver and Monica Mavrak, Women's Health Bureau,
Health Policy and Communications Branch; Louise Plouffe, Tye Arbuckle
and Barbara Sérandour, Centre for Healthy Human Development,
Population and Public Health Branch; and Priya Raju, Safe Environments
Programme, Healthy Environments and Consumer Safety Branch, Health
Canada
Shigellosis and First Nations Communities
Michael Clark, Primary Health Care and Public Health Directorate,
First Nations and Inuit Health Branch, Health Canada
Low rates of diarrheal diseases in developed nations such as Canada
reflect enormous improvements in hygiene and infrastructure during
the past century. Despite this progress, the recent Escherichia
coli outbreak in Walkerton is a reminder that some communities are
still vulnerable to diarrheal diseases linked to the environment.
A large outbreak of the diarrheal disease shigellosis also occurred
recently in Ottawa, due to a contaminated food source. Although
shigellosis outbreaks of this magnitude are not common in most Canadian
communities, many First Nations communities experience a disproportionate
burden of this disease as a result of a range of environmental conditions.
What is Shigellosis?
While cardiovascular disease and cancer may strike fear in the
hearts of many Canadians, most people probably don't know anything
about a potentially fatal disease called shigellosis. Shigellosis
is an acute, bacterial disease characterized by diarrhea, fever
and nausea. People may become infected by ingesting food or water
contaminated with shigella bacteria, or through fecal-oral,
person-to-person spread. The disease has an incubation period of
one to three days and lasts an average of four to seven days. Treatment
in Canada usually includes oral rehydration salts and sometimes
antimicrobial medications. Thus, case fatality in Canada is fortunately
quite low.
Diarrheal diseases are the second leading cause of mortality worldwide
among children less than 5 years of age. Shigella is one of five
organisms that cause the majority of pediatric diarrhea cases in
almost all geographic regions. It is the most significant cause
of bloody diarrhea in the world and is responsible for nearly all
episodes that are clinically severe or fatal.1
Shigellosis in Canada
All provinces and territories have legislation in place to ensure
that cases of shigellosis are reported to public health authorities.
In 1999, the reported incidence rate of shigellosis in Canada was
3.6 per 100,000 people. Children aged 5-9 years experienced the
highest rate of any age group, at 14.5 per 100,000. Overall rates
were higher in the Prairie provinces than in other parts of Canada,
with the highest rates in Manitoba (14.0 per 100,000).2
About the Data
Working in partnership with First Nations and provincial health
authorities, the First Nations and Inuit Health Branch (FNIHB)
of Health Canada provides primary health services and public health
programs in First Nations communities. Cases of shigellosis and
other notifiable diseases occurring in First Nations communities
are reported to FNIHB
regional offices. Notifiable disease data for 1999 were compiled
at the national level, analyzed and compared to 1999 data for the
entire Canadian population. As well, trend data of reported cases
in three regions and hospital separation data in two regions were
obtained from FNIHB
regional offices and computerized hospital discharge files, respectively.
A Disproportionate Burden
The First Nations on-reserve population for which shigellosis cases
were reported represents 1.1 percent of the Canadian population.
However, 23 percent of all reported shigellosis cases and 47 percent
of cases among children aged 0-14 years occurred in the First Nations
on-reserve population in 1999. The reported incidence rate of 74.1
per 100,000 among First Nations communities for that year was 26
times higher than the non-First Nations rate of 2.8 per 100,000.
The vast majority of First Nations cases (93.6 percent) in 1999
were reported in Alberta, Saskatchewan and Manitoba. Reported incidence
rates were consistently higher among First Nations communities than
in the non-First Nations populations of these provinces during the
late 1990s (see Figure 1). Hospital separation
rates for shigellosis were also higher among First Nations in Saskatchewan
and Manitoba throughout the decade. Over 80 percent of First Nations
shigellosis patients hospitalized in the two provinces during that
period were children aged 0-14 years. An epidemic in Manitoba during
the early 1990s affected more than half of the First Nations
communities in that province.
Most Canadians escape shigella infection during childhood, while
those who do become infected are generally exposed as a result of
travel in high-risk countries or during common-source outbreaks,
such as the recent food-borne outbreak in Ottawa. In developing
nations, where epidemics of shigellosis are common, the majority
of morbidity and mortality occurs among children. Notably, the age
distribution of shigellosis cases in the Canadian First Nations
population is very similar to what is generally observed in developing
countries.
Figure 2 shows 1999 age-specific incidence
rates in the First Nations and non-First Nations populations at
the national level. The highest rate was reported among First Nations
children aged 1-4 years (250 per 100,000). Eighty-six percent of
First Nations cases in 1999 occurred among children aged 0-14 years,
while 30 percent of non-First Nations cases were reported in this
age group.
Environmental Links
Researchers have identified important links between shigellosis
and a number of factors in the environment, including sewage disposal
methods, water supply systems and housing conditions.
Sewage Disposal
Humans are the only significant reservoir of shigella bacteria.
To be a source of infection, water and food must be contaminated
with human feces containing shigella. As a result, communities with
inadequate systems for sewage disposal are at increased risk for
shigellosis. People living in households lacking sewage removal
systems must sometimes use indoor pails for toilets. Children may
then be exposed to infection if feces and diapers are disposed of
in the yard. Communities with home sewage systems may also be at
risk for shigellosis if sewage disposal systems are improperly constructed.
Shigellosis cases have been linked to sewage backing out through
basement drains and poorly constructed surface disposal systems.
Families using wells may also be at risk if septic systems are located
near the well or well water source.
In many cases, sewage systems in First Nations communities do not
meet provincial design and installation standards. The proportion
of First Nations households with adequate sewage disposal increased
from 79 percent in 1990 to 94 percent in 2000.3
While this is a significant improvement, many people in areas where
shigella is endemic still do not have access to adequate sewage
disposal. In 1999, 22 percent of housing units in First Nations
communities in Manitoba lacked modern plumbing (an indoor toilet
and an assured supply of running water).4
Water Supply
Following the recent E. coli outbreak in Walkerton, concerns regarding
the quality of available drinking water have been raised
throughout the country. While the importance of ensuring a safe
supply of drinking water should not be underestimated, research
has shown that simple access to enough water for daily washing with
soap (water quantity) is a far greater determinant of childhood
diarrheal disease than water quality.1 Access
to a sufficient water supply for basic hygiene is a problem in many
First Nations communities - a concern one might expect to find in
developing countries but not in Canada.
In communities lacking a water delivery system, families must fill
drums from a standpipe or at lakes and rivers. Others may have water
delivered by truck to barrels in their houses or to household cisterns.
These methods of water supply limit the amount of water available
for hand washing, which can increase the risk of fecal-oral person-to-person
spread of shigella bacteria. A study of Manitoba First Nations communities
found that shigellosis rates were six times higher in communities
with truck-to-barrel water delivery than in communities with piped
systems. The association between the type of water delivery and
the incidence of shigellosis remained significant in a multivariate
analysis of risk factors.5
Crowded Housing
Overcrowded housing conditions increase the contact rate between
individuals and the risk of person-to-person spread of many communicable
diseases. Shigellosis is the most communicable of the bacterial
diarrheas. Only 10 to 100 viable organisms must be ingested for
the disease to occur in an individual.6 Forty
percent of people who are exposed to a case of shigellosis may be
infected through person-to-person transmission and attack rates
may be much higher among children.7 Shigellosis
rates in the Manitoba First Nations population have been shown to
increase with rising household densities.5 Overcrowded living conditions
is a problem in many First Nations communities - the average housing
density among First Nations on-reserve dwellings is 0.7 persons
per room, compared to the Canadian average of 0.4 persons per room.
Combatting Shigellosis
The high rates of shigellosis among First Nations people and the
impact of this disease on children's health are unacceptable. Short-
and long-term strategies must be implemented to combat shigellosis
and its environmental determinants.
Short-Term Prevention
In communities at high risk for shigellosis outbreaks, health promotion
can play an important short-term prevention role. Health promotion
messages should promote careful hand washing with soap and water,
proper food handling practices, breastfeeding of infants and boiling
water for infant formula. Children with shigellosis should be excluded
from daycare centres until their stool samples test negative for
the bacteria. Emphasizing good personal hygiene and sanitary food
preparation techniques is particularly important for those preparing
food for large cultural events, such as pow wows. Parents living
in communities with inadequate sewage disposal systems should be
educated to dispose of feces and diapers away from areas frequented
by children. Health promotion and education initiatives can be carried
out in community meetings, workshops and radio programs and by distributing
pamphlets in First Nations communities.
It is also important to carry out inspections of public facilities,
such as daycare centres and long-term care facilities, to identify
factors that may lead to disease. Environmental assessments of water
supply and sewage systems can identify problems of contamination.
These functions are mainly the responsibility of public health authorities
in First Nations communities, such as FNIHB
and First Nations transferred health authorities. Medical officers
of health, environmental health officers, community health nurses
and community stakeholders are all important in conducting assessments
and implementing effective corrective action. Early detection of
shigellosis cases and rapid intervention recently prevented a large
outbreak in one Alberta First Nations community.
Long-Term Prevention
Long-term strategies include those directed at combatting the environmental
determinants of shigellosis. Measures that will contribute to a
long-term reduction in disease burden are described briefly below.
Measures for the Long-Term Prevention of Shigellosis in a Community
- ensure that the water supply is adequate for daily washing
with soap
- provide sewage disposal and treatment systems
- ensure houses and sewage systems meet appropriate standards
for design and installation
- build septic systems at an adequate distance and downhill from
wells and well water sources
- introduce measures to limit overcrowded living conditions
Unfortunately, these solutions are beyond the control of public
health authorities, although they must advocate for changes when
links between environment and disease are found. Responsibility
for finding long-term solutions is shared among the Department of
Indian and Northern Affairs (INAC),
First Nations community leaders and the FNIHB.
It is not likely that a single environmental intervention will be
adequate to rid First Nations communities of shigellosis or developing
countries of common diarrheal diseases. Sufficient access to water,
adequate sewage disposal systems, reductions in crowded living conditions
and good personal hygiene are all needed to prevent shigellosis.8
These actions will also help to prevent other infectious diseases
with similar socioeconomic and environmental determinants, such
as hepatitis A and tuberculosis.
It is important to emphasize that not all First Nations communities
experience a disproportionate burden of shigellosis. The epidemiology
of the disease varies dramatically between regions and improved
sanitation has made a significant difference in many communities
where shigellosis was once common. Preventive programs must be maintained
and intensified in communities where shigellosis cases continue
to be reported.
The author would like to thank the FNIHB
Health Data Technical Working Group, Marion Perrin and Wadieh Yacoub
of Alberta Region, and Suzanne Martel of Manitoba Region for providing
shigellosis data and outbreak reports. The author would also like
to acknowledge Saskatchewan Health and Manitoba Health for contributing
hospitalization data.
Sulphur in Gasoline and Other Fuels: The
Case for Action (and Inaction)
Barry Jessiman and Rick Burnett, Safe Environments Programme, Healthy
Environments and Consumer Safety Branch (HECSB),
Health Canada; and Paul de Civita, Policy and Planning Directorate,
HECSB,
Health Canada
Due to concerns about the contribution of vehicles to poor air
quality, the Canadian government, in conjunction with the petroleum
industry, motor vehicle manufacturers, provincial governments and
public interest groups, undertook a detailed analysis of the impact
of sulphur levels in gasoline on air quality and health, and the
implications for Canada's fuel industry. Up until the late 1990s,
sulphur levels in gasoline were not regulated and, as a result,
varied widely across the country according to crude oil quality
and refinery capabilities. Sulphur in gasoline contributes directly
to tailpipe emissions and atmospheric pollution but, more importantly,
poisons catalytic converters. Catalytic converters are installed
on all modern automobiles and reduce a wide range of gasoline combustion
products that are toxic and contribute significantly to smog. The
authors explore how the evidence that emerged from this multi-stakeholder
process provided the basis for legislation regulating the sulphur
levels in gasoline.
A Three-Part Process
Generally speaking, air quality mitigation strategies use a variety
of tools to predict the potential for such strategies to deliver
air quality improvements and associated health benefits (see
Figure 1).
The sulphur in gasoline review, the most detailed of these efforts
conducted to date, was designed in three stages - process design,
fact finding, and the development of options and recommendations.
In the first stage, government and industry representatives developed
an overall plan for the process, while in the second stage, three
expert panels gathered evidence in the following issue areas - atmospheric
modelling,1 health and environmental impacts,2
and industry cost and competitiveness.3,4
In the third stage, government regulators built on the results of
the fact-finding stage to develop regulations for sulphur levels
in gasoline for Canada.
Building the Evidence
It is widely recognized that sulphur is a poison for many chemical
and catalytic processes. Evidence indicates that sulphur at levels
present in Canadian gasoline prior to regulation significantly reduces
the capability of the automotive catalytic converter. As a result,
cars emit much more sulphur dioxide, particulate matter, nitrogen
dioxide, sulphates and other smog-forming pollutants than they would
using gasoline with lower sulphur levels. The sulphur-in-gasoline
process used this knowledge as its starting point for determining
the implications of establishing a regulation concerning sulphur
levels in gasoline.
The fact-finding stage of the process focussed on a number of scenarios,
including six potential regulation levels for sulphur in gasoline,
ranging from 350 to 30 parts per million (ppm). The expert panel
on atmospheric modelling used the scenarios to project changes in
tailpipe emissions and the resultant effects on air quality. The
panel on health and environment, in turn, used these projected changes
to estimate impacts on human and environmental health.
While the most significant changes in air quality were projected
for sulphur dioxide and sulphate, significant reductions were also
predicted in several other pollutants, including carbon monoxide,
nitrogen oxides, volatile organic compounds and, to a small extent,
ozone. The primary source of data was epidemiological literature
focussing on sulphate as the primary pollutant and providing quantitative
estimates of its effects. A key element in the expert panels' deliberations
was the presumption that the sulphate signal captured in the published
literature was indicative of the type of emissions being reduced,
rather than being the causative agent. In fact, panel members acknowledged
the possibility that using this approach would underestimate the
true benefits of reducing sulphur levels in gasoline, since this
literature would only partially capture the effects of the reduction
of the other pollutants (i.e., the "soup" of chemicals
to which people are exposed and which cause effects).
At the same time, however, they felt that this literature provided
the most credible approach, as it contained sufficient material
to provide some estimate of the health effects that would be avoided
due to reductions, including premature mortality, chronic respiratory
disease, cardiac and respiratory hospitalization, emergency room
visits, asthma symptoms, restricted activity, and acute respiratory
symptoms and lower respiratory illness in children.
As part of the fact-finding phase, a monetary valuation of the
avoided effects was conducted, based on health economics literature.
The panels also calculated the actual costs of retrofitting refineries
to meet the various proposed sulphur standards, as well as the projected
impact of these standards on the competitiveness of the industry
both within Canada and abroad.
For the most stringent option considered (i.e., 30 ppm, the current
standard in California), it was determined that the cumulative health
impacts avoided over a 20-year period would include: 11 million
new cases of croup and pneumonia; five million days of asthma or
other restricting illnesses; 100,000 new cases of child and adult
chronic bronchitis; 9,000 emergency or hospital admissions; and
over 2,000 cases of premature mortality. While this option reduced
only a small percentage of total mortality (annual mortality in
Canada is approximately 240,000), hospital admissions, emergency
room visits, chronic bronchitis and other endpoints, it appeared
to be a cost-effective measure. The associated economic value of
avoiding these health effects (based primarily on monetary values
associated with premature mortality and illness costs) was estimated
to be greater than $6 billion over 20 years. The costs to industry
for complying with the proposed standards (based on new capital
costs and ongoing operating costs) were estimated to be under $3
billion over 20 years. It is important to note that, because of
data limitations, health benefits could only be calculated for the
seven largest Canadian cities (representing about 40 percent of
the national population), while refinery costs were calculated for
the entire Canadian industry. For this reason, the expert health
panel characterized the benefits as an underestimate of the true
total.
Regulating Action
Based on these findings, the Government of Canada chose the most
stringent standard of 30 ppm. Of the six options studied, this standard
resulted in the greatest difference between benefits and costs (see
Figure 2). It is interesting to note that, while the health
benefits were directly proportional to sulphur reductions, the costs
to industry were not. Small reductions in sulphur could be gained
by relatively minor interventions in most refineries, while more
ambitious targets (approximately 150 ppm) required significant investment
to install complex technologies. Having installed these technologies,
further reductions in sulphur levels do not require additional expensive
technology, only increased operating costs. As a result, costs were
not linear with reducing sulphur levels and, combined with other
(often refinery-specific) factors, resulted in the most stringent
level providing the greatest net benefits. Factors that played a
key role in the decision included the effects on catalytic converters,
the direct health benefits and reasonable costs.
The new regulation, as embodied in the Canadian Environmental
Protection Act (CEPA),
requires a phase-in period with a 150 ppm (average) standard that
started in July 2002, with the 30 ppm standard to be achieved by
January 2005. This regulation will bring Canadian sulphur levels
into line with current Japanese and California standards, as well
as with proposed US and European standards.
In the process leading up to the regulation's development, the
industry indicated that up to six of the eighteen existing Canadian
refineries might have to close, and that supply shortages and significant
price hikes in southern Ontario would result if the 30 ppm option
was chosen. After the regulation was passed, the industry lobbied
strongly for an amendment that would allow individual refining companies
to eliminate the phase-in period beginning in 2002 and move forward
the date of the 30 ppm requirement by one year. After detailed refinery-by-refinery
analysis, the government concluded that this strategy would result
in fewer health benefits than the existing regulation because moving
forward the 30 ppm date by one year would not fully compensate for
eliminating the phase-in period. Based on this further scientific
analysis, the government declined to amend the regulation. The industry
has since indicated that they do not expect to close any refineries
and that there are no technological or economic constraints in meeting
the regulation.
Lessons Learned: Moving Forward
As part of ongoing efforts to reduce the impacts of fossil fuel
combustion (e.g., home heating oil, diesel, heavy fuel oil), the
federal government is considering a series of sulphur-related measures.
However, it is important to note that the experts involved in the
sulphur in gasoline panel were greatly persuaded by the multi-pollutant
reductions afforded by reducing sulphur, which allowed the automotive
catalytic converter to perform at its design level. This is a key
consideration in attempting to extrapolate the sulphur in gasoline
results (even qualitatively) to other situations. For example, Canada
has announced a regulation that will require greatly reduced emissions
from diesel engines and require very low sulphur levels in diesel.
This regulation will require the installation of catalytic converters
and particle traps (both of which require very low sulphur fuel).
As was the case with gasoline, the significant sulphur reductions
will enable technologies that reduce a number of pollutants (nitrogen
oxides, particles, etc.). While the spectrum of pollutants is quite
different and the direct application of the sulphur in gasoline
results might be questioned, there is nonetheless a compelling case
for introducing the regulation and the promise of health benefits
as a result of doing so.
However, when the discussion moves to other fuels, such as light
fuel oil (LFO), heavy
fuel oil (HFO) and even
coal, the supposition that reducing sulphur will result in health
benefits is questionable. Currently, there is a movement to implement
regulations that will reduce sulphur levels in LFO
and HFO on the expectation
of health benefits. However, since a technological aspect (i.e.,
catalytic converters or particle traps) is not included, the reductions
in emissions will be confined to sulphur dioxide and sulphate, with
no expectation of reductions in nitrogen oxides, carbon monoxide,
ozone or volatile organic compounds. This factor limits the applicability
of the logic and rationale developed and followed by the sulphur
in gasoline study described above.
On the other hand, sulphate is a particle, a fact that would appear
to provide a justification for these measures as particulate matter
(PM) has been declared
toxic under the CEPA.
However, the strategy comes into question when one considers the
basis for labeling PM
as toxic. The evidence is almost exclusively based on large-scale
epidemiological studies (the same type of study used by the health
effects panel), which have found a significant and consistent association
between ambient PM
and mortality. The consistency of the findings from these studies
has convinced health and environmental agencies (including Health
Canada, the US Environmental Protection Agency and the WHO)
to support actions to reduce PM
in general.
It must be noted, however, that the PM
referred to in the above studies is a chemically complex mixture
and part of a "soup" of other air pollutants (e.g., carbon
monoxide, nitrogen dioxide, ozone, etc.). When a risk management
strategy reduces many of these constituents, there is a reasonable
level of confidence that the causative agents are being addressed.
Where one specific component is selectively reduced, there is less
confidence of a benefit.
To summarize, sulphur reductions will enable technology that reduces
a spectrum of air pollutants in the case of gasoline and diesel.
For other sulphur reduction strategies, only one or, at best, two
pollutants will be reduced. Current PM research is focused on finding
the factors that give PM
its toxicity. Such research, given time, will give much greater
focus to risk management strategies and potentially deliver much
greater health benefits for the money spent. Extrapolating the results
of the sulphur in gasoline analysis beyond a reasonable degree may
lead to misdirection of risk management resources and the development
of a potentially false sense of progress in combatting the population
health impacts of poor air quality.
Who's Doing What?
Who's Doing What? is a regular column of the Health Policy Research
Bulletin that looks at key players involved in generating policy
research within a specific theme area. Because the theme of "Health
and the Environment: Critical Pathways" covers such a broad
spectrum, the current column focuses on stakeholders active in the
specific policy research areas addressed in this issue of the Bulletin.
National Environment and Health Research Agenda
The Canadian Institutes of Health Research (CIHR)
are collaborating with Health Canada, Environment Canada and other
stakeholders to set a national research agenda on environmental
influences on health. The agenda aims to strengthen research, guide
funding decisions, and encourage the development of multi-disciplinary,
multi-sectoral research projects and innovative funding partnerships.
CIHR
developed a draft discussion paper for a national conference held
on September 13-14, 2002 (available at: http://www.cihr-irsc.gc.ca/institutes/ihdcyh/index_e.shtml).
Surveillance and Indicators
A number of organizations report on various aspects of the health-environment
relationship:
- In March 2002, the Environics Research Group conducted a poll
for Health Canada entitled "Air Pollution and Its Impact
on Health" with Canadian health care professionals. The study
addressed topics such as perceived effects of air pollution on
health and perceived seriousness of air-related health problems
in comparison to other health problems. For more information,
E-mail dddd_arad-draa_dedd@hc-sc.gc.ca
- The World Health Organization (WHO)
publishes various reports on environment and health, such as Environmental
Health Indicators: Framework and Methodology (available at:
http://www.who.int/environmental_information/
Information_resources/on_line_documents.htm).
- The Health Effects Institute (HEI)
is an independent, non-profit corporation that aims to provide
high quality, impartial and relevant research on the health effects
of pollutants from motor vehicles and other sources in the environment.
A collaborative initiative of the US Environmental Protection
Agency and industry, HEI
has published over 100 research reports (available at: http://www.healtheffects.org).
- The Health and Environment Group of the Centre hospitalier
universitaire de Québec (CHUQ)
brings together professionals and researchers from many disciplines
to research topics related to health and the environment. For
more information about CHUQ,
see: http://www.chuq.qc.ca/oms/en/mission/mission.htm
- The International Joint Commission (Canada/USA) held a Conference
on Environmental Health Surveillance in Québec City in
October 2000. Conference papers focussing on developing environmental
health indicators are available at: http://ottserver1.ottawa.ijc.org/hptf
- The goals of the Environmental and Occupational Health Surveillance
Working Group are to: identify relevant surveillance networks
and systems in Canada; assess needs and opportunities to strengthen
capacities; and recommend initiatives and priorities for Canada.
The Working Group reports to the Federal/Provincial/Territorial
Committee on Environmental and Occupational Health, while Health
Canada's Healthy Environments and Consumer Safety Branch (HECSB)
coordinates the Working Group's efforts in collaboration with
its partners. For more information, E-mail Sheryl_Bartlett@hc-sc.gc.ca
Women, Health and Environments
The Centres of Excellence for Women's Health Program, which is
funded by Health Canada's Women's Health Bureau, has released a
number of research papers on the subject of women, health and environments
(available at: http://www.cewh-cesf.ca/).
Children's Environmental Health (CEH)
The effect of the environment on children's health has been the
subject of several recent workshops and other initiatives of note:
- In May of 2000, the Five Natural Resources Working Group on
CEH,
established by Health Canada, organized a national workshop to
identify priorities and opportunities for interdepartmental collaboration.
A report on the workshop is available at: http://www.durable.gc.ca
- Health Canada and Environment Canada cohosted the Canadian
CEH
Research Workshop in Ottawa in March 2002. Among other objectives,
the workshop aimed to develop a Canadian CEH
research agenda. The program is available at: http://www.hc-sc.gc.ca/pphb-dgspsp/ceh
s-esm/wkshop_e.html
- The Commission for Environmental Cooperation (CEC,
Mexico/USA/Canada), the International Joint Commission and the
Pan American Health Organization are currently preparing a joint
project on measuring children's environmental health. The project
is part of the CEC
Cooperative Agenda for Children's Health and the Environment in
North America (see: http://www.cec.org).
- In 2001, the Canadian Institute of Child Health and the US
Children's Environmental Health Network cohosted a Global Forum
on CEH.
The resulting Joint Declaration on Children's Environmental
Health outlined significant threats to the health of the world's
children and identified areas in which immediate action was needed
(available at: http://www.cich.ca/postglobal.htm).
Food and Water Safety
A number of important initiatives are under way to address issues
related to food and water safety:
- Health Canada's Healthy Environments and Consumer Safety Branch
(HECSB)
recently collaborated with Environment Canada and several other
partners to deliver an international conference on water safety
in Ottawa on September 23-25, 2002. The objective of the conference,
entitled Drinking Water Safety: A Total Quality Management
Approach, was to provide a forum for innovative approaches
to such issues as ecosystems and health indicators of water quality
and science and policy guidelines for drinking water safety (available
at: http://www.neram.ca/Pages/events/events.htm).
- The Institute of Infection and Immunity of the Canadian Institutes
of Health Research (CIHR)
is taking the lead in establishing the Canadian Coalition for
Safe Food and Water. Designed to promote a coordinated approach
to research funding in this area, the Coalition comprises 17 partners,
including federal government departments and agencies, as well
as industry and professional bodies. For more information, E-mail
Kim_Elmslie@hc-sc.gc.ca
or jbray@cihr.ca
- The Toxic Substances Research Initiative (TSRI)
is a $40 million program that is comanaged by Health Canada and
Environment Canada. Launched in 1998, TSRI's primary goal is to
increase the level of knowledge about toxic substances and their
adverse effects. Research synopses are available at: http://www.hc-sc.gc.ca/hecs-sesc/tsri/index.htm
Health Impact Assessment
Health Canada has developed a draft Canadian Handbook on Health
Impact Assessment (HIA)
promoting the integration of HIA
into environmental impact assessment (EIA).
According to the Handbook, including the key determinants of health
in an EIA
framework is a cost-effective method for integrating the health
effects of development projects, programs and policies into the
decision-making process. The Handbook's three volumes are targeted
at health professionals, environmental assessment practitioners
and the public (available at: http://www.hc-sc.gc.ca/ehp/ehd/oeha/index.htm).
Using Canada's Health Data
Using Canada's Health Data is a regular column of the Health Policy
Research Bulletin highlighting some of the methodologies commonly
used in analyzing health data. This issue examines the role of health
surveillance and discusses how surveillance data are created, analyzed
and used.
Surveillance: What Is It?
Elizabeth Stratton, Centre for Surveillance Coordination, Population
and Public Health Branch, Health Canada, and Pierre Gosselin, Institut
national de santé publique du Québec
Health surveillance is the ongoing, systematic use of routinely
collected health data to guide public health action in a timely
fashion.1 Surveillance processes include the collection
of data, the integration, analysis and interpretation of that data
into surveillance products, and the dissemination of the surveillance
products to those who need to know. Surveillance has the following
key attributes: it generally involves the collection of data in
a continuous fashion; it is population based; and it produces information
and analytical products.
An essential component of both these definitions is the notion
of ongoing data collection of either new or existing data. New data
are collected prospectively for the purpose of surveillance, such
as with surveys that focus on specific conditions and/or risk behaviours.
For instance, Health Canada's Canadian Tobacco Use Monitoring Survey
(CTUMS)
generates new data on smoking behaviours in regular cycles. New
data are also collected on nationally notifiable diseases (conditions
where there are legislated mandates for reporting - from a local
public health region to the province or territory). A number of
communicable diseases are nationally notifiable by virtue of their
potential for serious population health consequences (e.g., measles,
meningococcal infections and sexually-transmitted diseases). Data
are immediately recorded for these conditions as a part of routine
public health disease prevention and control practice.
Existing data are retrieved for surveillance from a variety of
available sources. Examples include surveys and databases established
for purposes other than surveillance, such as hospital-based administrative
databases, disease registries and vital statistics. Chronic disease
surveillance relies heavily on existing data sources. The National
Diabetes Surveillance System, for example, uses administrative data
originating in provincial/territorial jurisdictions to provide national
level surveillance information on diabetes (http://www.diabetes.ca/Section_Professionals/index.asp).
Surveillance does not stop at data collection. Regardless of whether
new or existing sources are used, the data are then analyzed and
transformed into measures describing population health. For example,
how much disease is in the population (prevalence); how much newly-occurring
disease is in the population (incidence); and, for some diseases,
what proportion of the population has received an immunization against
the disease (coverage rate).
How Are Surveillance Data Used?
To be useful in protecting health, surveillance data must be collected
frequently, with rapid turnaround from raw data to analyzed surveillance
information indicating unusual or unexplained occurrence or pattern
of illness. Outbreaks of food-borne illness, for example, need to
be detected and reported quickly so that control measures can be
put into place. As such outbreaks can occur within hours of exposure,
the system must have "real time" detection capabilities.
Clusters of events in time are not the only indicators of health
problems - surveillance must also be capable of detecting rare and
unusual events where there may be only one or two cases. Such cases
may not be close in either space or time, but may indicate emerging
problems. An example is the detection of extremely rare cancers
associated with occupational exposures.
As previously noted, Health Canada receives information on a series
of notifiable diseases. Surveillance for these diseases is conducted
at the local, regional and provincial/territorial levels, with case
level reporting by condition, location, time, gender and age group
only at the national level - individuals cannot be identified.
The urgency and completeness of reporting also vary depending on
the specific condition. Measles is an example of surveillance where
each case must be reported to local public health offices as close
to "real time" as possible, to permit effective public
health follow-up on each case. For many other diseases, the aim
of surveillance is to detect and respond to trends in disease activity.
Influenza, for example, is consistently under-reported; it is neither
practical nor necessary to count each case in order to obtain a
trend for influenza activity in the population.
Surveillance Information Products
Health Canada produces and distributes a variety of timely surveillance
information:
Did You Know?
Did You Know? is a regular column of the Health Policy Research
Bulletin examining aspects of health research and data that may
be subject to misconceptions. In this issue, we examine some of
the considerations that should be taken into account when interpreting
whether or not research results are statistically significant.
A Journey into Statistical Significance
Martin Ducharme, Applied Research and Analysis Directorate, Information,
Analysis and Connectivity Branch, Health Canada
Consider the following scenario: a team of researchers is studying
the discharge of pollutants into water by a particular industry
to determine whether a new technology is cleaner and thus better
for the environment than the system currently in use. They know
that the average concentration of a toxin observed in water surrounding
a sample of facilities using the current system is 4.0 mg/l. For
a sample of facilities using the new technology, the average concentration
of the same toxin in surrounding waters is 3.2 mg/l. Should they
conclude that the new system is better for the environment? Should
they recommend that this new technology be used in the facilities
still using the standard system?
Answering these questions may not be as simple as it appears. This
column explores the concept of statistical significance and explains
its most important elements. The discussion is intended to provide
readers with a better understanding of some of the statistical terminology
they may encounter while reading research reports.
Statistical Inference, Hypothesis Testing, P Values . . . What
Do They Mean?
For many people, the notion of statistics is limited to averages
or the numbers used to describe how well their favourite teams or
players are faring. In fact, these are part of a field called descriptive
statistics - numbers that deal with the presentation, organization,
summarization and, hence, the description of data.
The statistics examined in this column are quite different. Because
studies can consume considerable time and resources, researchers
must invariably limit their investigations to samples of
the targeted populations. As a result, they are only able to produce
estimates of the parameters for which they assume a true value exists.
Any measurement based on a sample will differ from the true value
by some amount as a result of random processes or chance. This is
the main reason that the results of opinion polls are accompanied
by phrases such as "with a three percentage point margin of
error, 19 times out of 20."
Therefore, analysts need tools to determine the likelihood that
a conclusion drawn from a sample is true. This way of generalizing
results from a sample to the entire population is called inferential
statistics. Going back to the example described above, this
means testing whether the lower measured concentration of the toxin
is truly the result of a cleaner technology or whether it could
be due to some random factor. Statistical significance is used to
demonstrate that an effect did not occur by pure chance, but is
more likely the result of a particular relationship between variables.
Hypothesis Testing
A bit like a criminal suspect who is considered innocent until
proven guilty, the observed results of a study are first considered
to be the same as what might have occurred as a result of chance
alone. This step is called the null hypothesis and it usually
states that a variable has no effect on another, or that two or
more variable distributions are no different from one another. The
null hypothesis is always the most restrictive and its complement
is called the alternative hypothesis. For the pollutant discharge
example, the null hypothesis is that the toxin level is no different
with the new technology than it is with the standard system (i.e.,
it is equal to 4.0 mg/l), while the alternative hypothesis
is that the toxin concentration is different.
P Values
The most common way to test if the null hypothesis holds true is
to look at the probability of the observed outcome under that hypothesis.
For the example above, this would mean looking at the probability
of observing a concentration of 3.2 mg/l when the true concentration
is really 4.0 mg/l. This probability is what is called the P
value and it is formally defined as the probability of observing
a test statistic as extreme as or more extreme than the one actually
observed when the null hypothesis is true. The smaller the P value,
the smaller the probability of the observed outcome under the null
hypothesis.
The result is said to be statistically significant when one has
sufficient confidence to rule out the possibility that it might
have occurred according to the null hypothesis. The smaller the
P value, the more confident one can be in ruling out the null hypothesis.
Analysts use threshold values to determine the statistical significance
of a result. As an example, a result could be considered statistically
significant when the probability of observing it under the null
hypothesis is smaller than 5 percent (i.e., a P value of less than
0.05). The threshold value is called the significance level
and it is often expressed as alpha ( a ). There are no rules of
thumb in determining the significance level, but it is usually fixed
at 1 percent, 5 percent or 10 percent.
A P value smaller than the determined significance level means
that the observed event is sufficiently unlikely under the null
hypothesis that the latter can be rejected and the result is said
to be statistically significant. Although it is not explicitly stated,
there is a tacit presumption that the alternative hypothesis provides
a more reasonable explanation for that same event. A P value higher
than the significance level means that the null hypothesis cannot
be ruled out with confidence and the result is said to be non-statistically
significant (note that one never accepts the null hypothesis, only
rejects it or fails to reject it). In the current example, using
a significance level of 5 percent, one would need to find a P value
smaller than 0.05 to reject the null hypothesis of no difference
in the concentration level of the toxin.
Confidence Intervals
Finally, another way to see whether a result is significant or
not is to build confidence intervals that would include 1-alpha
percent (100 percent minus the significance level) of the observations.
If the value of the null hypothesis remains outside the interval,
the result is said to be statistically significant and the null
hypothesis is rejected; otherwise, the result is non-statistically
significant and one fails to reject the null hypothesis. For instance,
if the 95 percent confidence intervals around the 3.2 mg/l measure
exclude the value of 4.0 mg/l, the null hypothesis is rejected.
The Limits of P Values and Statistical Significance
The reporting of P values to determine the statistical significance
of research results has become widespread because of their ease
of use and the fact that most statistical software packages automatically
produce P values for each estimated parameter. However, many articles
published in educational or statistical journals have criticized
the use of P values because they are often misinterpreted or misused.
One of the most widespread criticisms is that P values and statistical
significance say nothing about the magnitude or the practical
significance of the results. It is therefore possible for an
effect of little practical importance to achieve a high degree of
statistical significance, as it is possible for an important effect
to be missed because a model lacks the statistical power to detect
it at a given level of significance. However, statistical significance
and practical significance should be viewed as complementary concepts
rather than as competing ones. Since resources are limited, it's
important to know about both the likelihood and the magnitude of
the impact before investing in a new initiative.
Test Your Knowledge
Suppose there are five new technologies reported to reduce the
concentration of a specific toxin. The results of a study on the
effects of these technologies are provided in the table below. Note
that the measure reported is the observed reduction in the concentration
compared to the standard system. Using a 5 percent significance
level, try to determine which technologies have a statistically
significant impact on the concentration of the toxin. Which ones
have an impact of practical importance if it has been established
that any reduction of less than 0.5 mg/l would not have a significant
impact on the ecosystem and the health of the population? Should
any of these technologies be recommended as a cleaner and healthier
substitute to the standard system?
Technologies
|
Observed reduction mg/l
|
P value
|
95% confidence interval
|
1
|
0.1
|
<0.0001
|
(0.08-0.12)
|
2
|
1.8
|
0.0034
|
(0.61-2.99)
|
3
|
0.8
|
0.0010
|
(0.40-1.20)
|
4
|
0.1
|
0.5065
|
(-0.20-0.40)
|
5
|
1.8
|
0.2330
|
(-1.18-4.78)
|
Answers to "Test Your Knowledge"
- Technologies 1, 2 and 3 are statistically significant at the
5 percent level. The P values for these technologies are smaller
than 0.05 and their 95 percent confidence intervals exclude the
value of zero.
- With regard to confidence intervals, only the second procedure
seems to be of any practical significance, while the results for
the third and fifth procedures are unclear because their respective
confidence intervals include values both above and below 0.5 mg/l.
- Only the second technology has both statistical and practical
significance. This technology is therefore cleaner for the environment
and healthier than the standard system currently in use. However,
other studies might be required before this technology becomes
the new standard. As an example, one might want to conduct a cost-benefit
analysis to see whether the benefits of this new technology are
worth its costs.
New and Noteworthy
New and Noteworthy is a regular column of the Health Policy Research
Bulletin highlighting "up and coming" policy research
in the health field.
Health Canada Research Forum: From Science to Policy
On November 18-19, 2002, scientists and researchers from across
Health Canada will come together in Ottawa to network and showcase
their work and achievements. Sponsored by Health Canada's Health
Research Secretariat in the Office of the Chief Scientist, the departmental
research conference will include discussions organized around three
broad themes (contaminants in food, air and water; children's health;
and genomics and health), while poster sessions will showcase the
full range of research and science initiatives conducted by Health
Canada. The department's partners will also be invited to attend
and learn more about the department's science and research activities.
For more information, E-mail Stephanie_Wilson@hc-sc.gc.ca
Funding for Health Policy Research
A strategic, targeted contribution program of Health Canada's Applied
Research and Analysis Directorate (ARAD),
the Health Policy Research Program (HPRP) generates a range of extramural
policy-relevant research designed to meet the needs of the department.
HPRP supports research and development projects, policy-relevant
projects, workshops, seminars and conferences, and federal/provincial/territorial
health research partnerships. Watch for upcoming requests for proposals
in Health Canada's priority areas on the ARAD
website (http://www.hc-sc.gc.ca/iacb-dgiac/arad-draa/english/rmdd/funding1.html).
Infrastructure for Communicable and Chronic Disease Surveillance
The Health Surveillance Working Group (HSWG)
has a mandate from the Advisory Committee on Health Infostructure
(ACHI)
to identify ways and means of enhancing health surveillance in Canada.
Health Canada's Centre for Surveillance Coordination (CSC)
provides secretariat support to the HSWG.
On direction from the HSWG,
four breakthrough studies/papers on health surveillance have been
undertaken and are now available from the CSC:
- Data Definitions and Standards for National Notifiable Disease
Reporting
- Data Definitions and Standards for National Immunization
Records Network
- National Surveillance for Chronic Disease in Canada - Charting
a Path Forward
- Situational Analysis for Chronic Disease Surveillance Systems
and Networks in Canada
More information is available at: http://www.hc-sc.gc.ca/pphb-dgspsp/csc-ccs/
or by calling (877) 430-9995
Biotechnology Surveillance Project
Housed in Health Canada's Centre for Surveillance Coordination
(CSC),
the Biotechnology Surveillance Project (BSP)
is developing a national surveillance system to monitor potential
late health effects on humans of biotechnology products regulated
in Canada. The BSP's
areas of focus include post-market surveillance of bio-engineered
vaccines and therapeutics, and post-market surveillance of genetically
modified foods.
Recent work in the area of post-market surveillance of genetically
modified foods included a Global Environmental Scan detailing
international efforts in this area and identifying global experts
in the field. A follow-up to this work, an international publication
on A System Dynamics Approach to Assessing the Economic Implications
of Post-Market Surveillance of Genetically Modified Foods, was
completed in Sepember 2002. The First International Conference on
Post-Market Surveillance of Genetically Modified Foods, hosted by
Health Canada on October 16-17, 2002, offered a unique opportunity
to position Canada as a global leader in fostering international
knowledge sharing and collaboration related to post-market surveillance
of genetically modified foods. More information is available at:
http://www.hc-sc.gc.ca/pphb-dgspsp/csc-ccs/
Mobilizing Population Health
The population health approach is aimed at maintaining and improving
the health of all Canadians, as well as reducing inequalities among
population groups. A key focus of Health Canada's Population and
Public Health Branch (PPHB),
the approach directs health improvement interventions toward broad,
systemic determinants of health, many of them outside the traditional
health care system.
Case Studies of the Regional Mobilization of Population Health
- Final Report presents the findings from six initiatives undertaken
by PPHB
regional offices across Canada, including a cross-case analysis
focussing on lessons learned. The results are intended to inform
practice in the field and to help market the population health approach
to key decision makers in health policy and planning. The document
is available on the Population Health website at: http://www.hc-sc.gc.ca/hppb/phdd/case_studies/index.html
Levels of Service in Prenatal Nutrition Programs
A new database provides one-stop electronic access to project-level
data and descriptive information about Ontario projects funded under
the Canada Prenatal Nutrition Program (CPNP).
Compiled by the Healthy Child Development Team, Population and Public
Health Branch, Health Canada (Ontario Region), the database allows
program consultants to explore and compare individual projects and
to identify projects that deviate from Ontario-wide norms. Two reports
integrate the information contained in the database with research
literature on "best practices" in prenatal programs.
In the next phase of the project, upcoming research on best practices
in prenatal programs will be combined with information contained
in the database to develop core standards for Ontario CPNP
projects. For more information, contact: Nicole_Kenton@hc-sc.gc.ca
Putting the Population Health Approach into Action
The Social Planning and Research Council of BC (SPARC)
recently received funding from the Population Health Fund to analyze
and synthesize lessons learned in putting the population health
approach into action in community-based projects. The result is
a document entitled Creative Spice: Learning from Communities
about Putting the Population Health Approach into Action. Eleven
projects focussing on a range of populations and health issues shared
their experiences with SPARC.
Of particular interest to policy makers are the discussions about
the need to educate a broader array of audiences and to expand community
capacity building and the length of community-based initiatives.
The project was sponsored by the BC/Yukon Regional Office of the
Population and Public Health Branch of Health Canada. The document
is available on the Population Health website at: http://www.population-health.com
Mark Your Calendar
What
|
When
|
Theme
|
The Pan American Health Organization's Health Promotion Forum
in the Americas |
|
Promoting health in the Americas through follow-up on the
Mexico Declaration, presenting experiences and good practices,
and networking |
2002 National Policy Research Conference on Future Trends:
Risk |
|
Extending the understanding of risk in the Canadian context |
Health Research in Rural and Remote Canada: Meeting Challenges,
Creating Opportunities |
|
Various themes, such as community health and Aboriginal health
|
XIXth International Methodology Symposium and Workshops: Modelling
Survey Data for Social and Economic Research
|
|
Subject areas of interest include national statistical accounts
and evaluation of social programs |
24th Annual Research Conference of the Association for Public
Policy Analysis and Management (APPAM)
|
|
What if . . .? Assessing the public policy and management
implications of social science research |
Centre for Health Services and Policy Research: 15th Annual
Health Policy Conference |
|
Genetic testing: Help, hope or hype |
Health Canada Research Forum: From Science to Policy |
|
Contaminants in food, air and water; children's health; and
genomics and health |
12th Annual National Canadian Home Care Association's
Conference |
|
Maximum impact: Home care's role in health care
reform - ideas, information, implementation and impact |
Social Determinants of Health Across the Life-Span: Canadian
Perspectives |
|
A comprehensive examination of issues within a social determinants
of health framework |
Third National Conference on Tobacco or Health |
|
Science and policy in action |
References
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5. Health Canada, Bureau of Reproductive and Child
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6. Carson R. Silent Spring. Boston: Houghton
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2. United Nations Environment Programme. Stockholm
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