 |
 |
 |
||||
|
||||||
|
|
 |
 |
 |
 |
 |
|
|
  |
 |
 |
 |
 |
|
||||||
|
 |
ContextApproximately 23,000 existing substances currently in use in Canada are being reviewed to determine if they are toxic or capable of becoming toxic. New substances, which include chemicals, polymers, and products of biotechnology, are assessed before their release into the marketplace. Fifty-two of these substances are defined as toxic by the Canadian Environmental Protection Act, 1999 (CEPA 1999). A substance is toxic if it enters the environment in a quantity that has or may have a harmful effect on the environment or human health. Toxic substances come from many industrial and household sources. These substances can be harmful to the environment, aquatic life, endangered species, and human health. Certain substances, such as mercury, DDE breakdown product of DDT), and PCBs, build up in organisms over time, become increasingly concentrated (bioaccumulation), and have a stronger toxic effect as they move through the food chain (biomagnification).IndicatorsThe first step in managing risk from toxic substances is recognizing that risk. The number of substances on the CEPA List of Toxic Substances has grown as progress has been made in assessing existing and new substances. When CEPA was first passed in 1988, there were 9 substances on the List. In 2002, there are 52. Once a sub-stance is placed on the list, management strategies are developed and implemented to control its release into the environment.The National Pollutant Release Inventory (NPRI) provides information on the releases and transfers of key pollutants to air, water and land from large industrial and commercial sources in Canada. Only facilities that meet the NPRI reporting criteria are required to report. Mobile sources (e.g. trucks and cars), households, certain sector activities such as agriculture and education and facilities that release pollutants on a smaller scale are not reflected in the NPRI. The list of substances reportable to the NPRI changes from year to year. For example, the list may change due to the addition of new substances, deletion of others and changes in the release or transfer thresholds/levels. To compensate for these changes, a set of "matched data" is used for trend analysis. The matched data refers to the common set of substances and reporting criteria, which can then be used for comparisons over a specific period of time. Reliable matched data from 1995 to 2000 are available for 15 toxic substances. Of the 15, on-site releases have decreased for 7, changed little for 3, and increased for 5. There has been important progress made towards reducing emissions of a number of toxic substances. For example, mercury emissions to air saw an overall decrease of 77% from 1990 to 2000. Emissions were reduced primarily from incineration operations as well as the steel and primary base metals sectors. Emissions from electric power generators increased over this time period. The concentrations of persistent organic pollutants (POPs), such as DDE and PCBs, in wildlife vary considerably among individual animals as well as among locations across the country. However, contaminant concentrations in the eggs of Double-crested Cormorants have declined since the early 1970s, with most gains made before 1990. Scientists suspect that the lack of further concentration declines, despite the banning of these chemicals in Canada, may result from long-range transport, the slow release of contaminant residues from bottom sediments, and, in the case of PCBs, the release of PCBs from storage and dump sites as well as products still in use.
ActionsThrough CEPA 1999, the Government of Canada seeks to protect the environment and human health from the risks posed by toxic substances. CEPA includes effective and flexible provisions for preventing pollution, controlling toxic substances, managing wastes, and preventing and addressing environmental emergencies. The Act provides clear objectives for assessing new and existing substances and managing risks through a wide range of measures, including codes of practice, guidelines, pollution prevention plans, economic instruments, and regulations. Efforts are also made to promote early action through complementary voluntary initiatives, such as the Accelerated Reduction/Elimination of Toxics (ARET) program.A Canada-wide standard (CWS) for mercury for coal-fired electricity generators is being developed to help address the issue of increased generator emissions. A phased approach to further emission reductions of benzene has also been endorsed through the CWS process. The Benzene in Gasoline Regulations set limits for the amount of benzene in gasoline and for a benzene emissions factor. In the past decade, Canada has developed the Toxic Substances Research Initiative, as well as the Toxic Substances Management Policy, which sets out two tracks for the management of toxic substances: virtual elimination and life cycle management. The NPRI provides Canadians with access to information on key sources of pollution in their communities. The National Air Pollution Surveillance (NAPS) program collects data on the components of smog, and can help identify links between air pollution and human health. The Northern Contaminants Program, established in 1991, is directed at reducing or eliminating contaminants in high-risk foods harvested in Canada's North. Canada was the first nation to ratify the Stockholm Convention on Persistent Organic Pollutants, which identifies problematic substances for which comprehensive global action is required. Canada has also developed trilateral action plans with Mexico and the United States on chlordane, DDT, and PCBs under the Commission on Environmental Cooperation, an organization created under the North American Agreement on Environmental Cooperation. This agreement complements the environmental provisions of the North American Free Trade Agreement. LinkagesOther chemicals of concern, because of their potential toxic effects on the environment and human health, are heavy metals for which trends were not available and pesticides. Certain water quality indicators may predict levels of chemical contaminants in wildlife over time. Toxic compounds in wildlife are used as an early warning signal for effects on human health and ecosystems. For example, contaminants in marine mammal tissue provides a measure of the health of marine ecosystems; contaminants in polar bear tissue provides a measure of the health of northern ecosystems. Climate change and increased ultraviolet B radiation may affect the behaviour of toxic substances in the environment.ChallengesMore work must be done to understand and limit the risks posed by the thousands of chemicals released into the environment annually. Governments, industry, and communities have to work together to address this challenge. Progress continues towards meeting the challenge of categorizing the approximately 23000 substances in use in Canada by September 2006. New scientific and technological developments offer not only opportunities, but also new and complex risks to the health and environment of Canadians. An increased awareness of the importance of prevention will be crucial in dealing with these risks. |
 View in print format |
 Previous
Top 
Next
Indicator 
|
|
|
| | What's New | About Us | Your Environment | Information/Publications | Weather | Home | |
|
|
| Français
| Contact
Us | Help | Search
| Canada Site
|
|
|
| The Green LaneTM, Environment Canada's World Wide Web site | ||
| Last updated: 2005-04-11 | Important Notices and Disclaimers | |
PDF (2867kb)
