Air quality research: making a difference

Environment Canada’s air quality science is making a difference in the lives of Canadians.  The Government of Canada is committed to clean air and in strengthening the services to Canadians that help protect their health on a daily basis from the negative effects of air pollution, and to provide weather and environmental predictions and services to reduce risks that may be associated with air pollution.

The Department’s Air Quality Research Division plays a key role in supporting this priority by:

• conducting research and measuring the physical, biological and chemical processes that determine the chemistry of the atmosphere.
• undertaking air quality monitoring and measurement techniques.
• developing and using ground-based observing technology such as the Brewer spectrophotometer to research ozone, nitrogen dioxide, and the ultraviolet ground-level solar spectrum.
• developing tools and techniques (lidar - light detection and ranging) to detect and characterize airborne particulate pollution and to contribute to an understanding of its dispersion and motion in the atmosphere.
• conducting satellite remote sensing to measure ozone levels and assess ozone depletion

The research and results of this work are used by Canadians to help them understand how the air quality around them may impact their health, and also by policy- and decision-makers to support the development of policies, regulations and abatement strategies. Some of the many specific ways in which the Division’s team of research scientists, chemists, engineers, and other specialists are delivering on these federal priorities include:

Air Quality Health Index (AQHI)

The Air Quality Health Index was developed jointly by Environment Canada and Health Canada to communicate the health risks posed by air pollution.  Environment Canada science supports the AQHI by:

• Developing air quality forecasting techniques and associated modelling research.
• Conducting systematic measurements to assess the impact of human activities on atmospheric constituents.
• Analyzing air pollutants known to harm human health, which are used as indicators in the index - ground-level ozone, particulate matter, and nitrogen dioxide.

The AQHI is included in Environment Canada’s weather forecasts.

Ultraviolet Radiation Research and Monitoring (UV Index)

Canadian scientists developed the UV Index which is now used by countries around the world to issue nation-wise daily UV forecasts to their citizens. (Increased UV-B radiation can cause melanoma and other skin cancers, cataracts, and immune deficiencies if stratospheric ozone does not absorb it).

The index predicts the strength of the sun’s UV rays, based on daily changes in the ozone layer and takes into consideration the amount of ozone depletion occurring, on a daily basis.

The Brewer Spectrophotometer, developed by Environment Canada scientists and used internationally, routinely collects and processes data measuring total ozone and special UV irradiation and is used for forecasting, trend analysis and ongoing scientific research.

The UV index is included in Environment Canada’s weather forecasts.

Air Quality Links to Health Issues

• New air quality mapping techniques enable the interpolation of air quality monitoring data across most of Canada.
• In conjunction with Health Canada, this information is combined with population, to determine population exposure at various levels of particulate matter (PM) and ozone.
• Improved characterizations of air quality on a local scale enabled scientists to determine that exposure to traffic-related air pollutants was associated with a 17% increase in all cause mortality and a 40% increase in circulatory mortality in a vulnerable cohort from Toronto, as well as a prevalence of diabetes among women in Toronto and Hamilton.

GEM-MACH15 - Improved Air Quality and Chemistry Modelling

The newly developed GEM-MACH15 model is the first common modelling platform for atmospheric chemistry. It is capable of modelling smog levels for Canada and allows scientists to integrate meteorological and atmospheric chemistry information simultaneously.

Examples of model evaluation - ozone forecasts for summer and winter; trajectory predictions for wind-blown dust emissions and North American wildfire emissions.

The air quality modelling framework is being expanded to meet emerging demands for information for a larger suite of chemicals and in a changing climate.

Monitoring Changes in Air Quality

The National Air Pollution Surveillance (NAPS) program, focusing on urban air quality, has found that from 1970 to 2008, particulate matter has decreased by over 50% in ambient air, lead has decreased by 90% and sulphur has decreased by 96%.

Environment Canada scientists have found that volatile organic compounds, including benzene, have declined significantly since measurements started in 1990.

Event-based sampling enables the scientists to collect data on new chemicals identified for regulation, e.g., levo­glucosan, a tracer for wood smoke and potential indicator of impact of residential wood combustion on PM_2.5 levels.