Monitoring the "Tailpipe of North America"

Visitors to New Brunswick are impressed by its picturesque and pristine natural landscape of lakes, mountains and wilderness. But a stranger from a distant land lurks through the southern half of the province, unseen for the most part by the human eye. Its name is smog, and its presence is making breathing difficult for many residents--particularly children and those with respiratory problems.

Smog, or ground-level ozone, is created when solar radiation interacts with various airborne pollutants and their precursors. Southern New Brunswick receives a significant portion of North America's air pollution, which can travel up to 800 kilometres per day. Approximately 80 per cent of the smog in the province originates from the eastern United States, the Ohio Valley, southern Ontario and Quebec.

To help reduce the impact of smog on human health, Environment Canada scientists in Eastern Canada began to collect data and develop a forecasting model and operational method for predicting smog concentrations. Over the years, the accuracy of these forecasts has increased significantly--not only because of technological advances in the sensitivity of the monitoring equipment, but also because of the innovative use of deterministic as well as statistical numerical prediction models. As knowledge of smog behaviour has increased, the scientists involved have also become better forecasters.

To help reduce the impact of smog on human health, Environment Canada scientists in Eastern Canada began to collect data and develop a forecasting model and operational method for predicting smog concentrations. Over the years, the accuracy of these forecasts has increased significantly--not only because of technological advances in the sensitivity of the monitoring equipment, but also because of the innovative use of deterministic as well as statistical numerical prediction models. As knowledge of smog behaviour has increased, the scientists involved have also become better forecasters.

Unlike a typical coastal storm, which migrates up the eastern seaboard and hits each community in its path, a plume of smog may travel the same route, but--depending on local and regional wind velocities, cloud movement, low-level temperature and stability profiles or the impact of fog--could bypass some communities and affect others. These extremes and smog's interaction with regional geographic and climatic variables has led to a greater, more refined and sophisticated understanding of smog by scientists at the New Brunswick Weather Centre in Fredericton.

In 1993, these scientists and their counterparts at the New Brunswick Department of the Environment entered into a partnership under the Smog Advisory Program to provide smog forecasts for the Saint John area. Special bulletins were issued to alert the public when smog concentrations were expected to exceed 82 parts per billion, a level accepted as the national threshold.

Four years later, the success of the program, coupled with the discovery that lower concentrations of smog had a greater impact on human health than previously realized, resulted in its expansion into daily smog forecasts. These forecasts predict smog levels for the next 48 hours--providing air quality readings, categorizing conditions as poor, fair or good, and explaining how weather conditions are affecting the situation. At the end of each forecast, listeners are given advice on how to reduce smog, and directed to visit their physician if they are experiencing air quality-related health problems.

The air quality monitoring station at Forest Hills, New Brunswick, has been in continuous operation since 1961, making it one of the oldest in Canada.

In 1998, the installation of a new monitoring station in Moncton proved that daily smog levels in the city were as significant as those in the more heavily industrialized Saint John region. This May, scientists from the New Brunswick Weather Centre and various provincial departments responded to this discovery by expanding the Smog Forecast Program to the greater Fredericton and Moncton areas. While it is still too early to identify the impact of the program on the health of residents, the issuance of daily smog forecasts enables people in New Brunswick to make informed decisions on how to better protect themselves, their families and the environment from the effects of air pollution.

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