Every day, the average adult breathes about 15,000 to 20,000 litres of air. 1

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1 Every day, the average adult breathes about 15,000 to 20,000 litres of air. 1 Children are uniquely vulnerable to environmental contaminants because, relative to their body size, they breathe in more air than adults. A child s body will therefore take in and absorb more contaminants than that of an adult. 2 INDOOR AIR QUALITY AND HEALTH Canadians spend close to 90% of their time in an indoor environment. 3 Most of this time is spent in our homes. Many of the exposures thought to be associated with asthma occur predominantly indoors. Interventions to limit or eliminate exposures there have the potential to help asthmatics and perhaps result in primary prevention of the illness. 4 Some indoor air pollutants, such as formaldehyde, can be found in higher concentrations in our homes than outdoors. 5 It is estimated that million deaths per year worldwide could be attributed to indoor air pollution. Approximately 1 million of these deaths occur in children under 5 years of age due to acute respiratory infections, and significant proportions of deaths occur due to COPD and lung cancer in women. 6 Indoor air pollution ranks 10 th among preventable risk factors contributing to the global burden of disease. 7 1 Ontario Ministry of the Environment. 2 Pollution Probe. 3 Health Canada Clearing the Air: Asthma and Indoor Exposures. National Academy of Sciences Windsor Air Quality Study, Ontario Ministry of the Environment. 6 Viegi, Simoni et al. Indoor Air Pollution and Respiratory Disease. Int J Tuberc Lung Disease 8(12); IUATLD. 7 Ibid. 1

2 WHAT IS SMOG? Smog refers to a noxious mixture of gases and particles that often occur as a haze in the air. Its main ingredients are ground-level ozone and particulate matter. 8 WHERE DOES SMOG COME FROM? Air pollution in Ontario comes from factories, power plants, and smelters; mobile sources such as cars, buses, trucks, planes, marine vessels and trains; and finally, natural sources such as forest fires. A large amount of Ontario s smog originates from emission sources in the United States. Research shows that neighbouring U.S. states are major contributors to ground- level ozone and fine particulate matter in Ontario. 9 The map above shows the area from which southern Ontario air originates during days of widespread elevated smog. Historically, most episodes of elevated smog in Ontario come from emission sources in the U.S. Midwest Environment Canada. 9 Ontario Ministry of the Environment Ontario Ministry of the Environment. 2

3 HOW IS AIR QUALITY MEASURED? The Air Quality Index (AQI) is a rating scale for outdoor air in Ontario. Six key air pollutants are monitored by the Ministry of the Environment as part of the AQI: sulphur dioxide, ozone, nitrogen dioxide, total reduced sulphur compounds, carbon monoxide and fine particulate matter. These pollutants were chosen because they have an adverse effect on humans and the environment. Data are compared to ambient air quality standards for each of the six air pollutants and then converted into the AQI scale, ranging from 0-15 (very good) to 100+ (very poor). 11 Poor means the AQI reading is expected to be at least 50. If poor readings are predicted to be sustained over a period of time and over a wide area, then a Smog Alert is issued for that area. 12 The AQI is not as protective of health as initially believed. An Ontario study found that even very low levels of pollutants may increase hospital admissions for respiratory disease, with infants being the most affected. 13 To better advise Canadians about the health risks of air pollution, Canada is adopting the Air Quality Health Index (AQHI). The new index, found at is the world's first index to communicate the health risks associated with the mixture of air pollutants we breathe and to provide protective health advice to reduce that risk. 14 OUTDOOR AIR QUALITY AND HEALTH Smog has been identified as contributing factors in thousands of premature deaths across the country each year, as well as increased hospital visits, doctor visits and hundreds of thousands of lost days at work and school. 15 Air pollution studies have linked air pollution with lung cancer, heart attacks, strokes, high blood pressure, congenital heart defects, asthma, and even brain damage. Diabetics, asthma patients, those with congestive heart failure, and children who play outdoors are identified as being at increased risk Ontario Ministry of the Environment Ontario Ministry of the Environment Effects of low ambient levels of ozone and sulphates on the frequency of respiratory admissions to Ontario hospitals. R. Burnett et al. Environmental Research, 65: Environment Canada Environment Canada. 3

4 Air pollution has been clearly linked to respiratory diseases such as asthma and bronchitis, and can negatively impact pre-existing health conditions such as diabetes and heart problems. Pregnant women, children and the elderly are especially at risk of experiencing the adverse effects of exposure to air pollution. 17 Even at low levels, air pollution can contribute to a variety of harmful health effects, ranging from premature death to asthma to coughing to eye irritation. 18 Smog is a problem in a number of Ontario cities and poses a threat to human health. Emergency room visits and hospital admissions rise as the amount of ground-level ozone in smog increases. When there is more particulate matter in the air, death rates are higher. 19 Environment Canada estimates that at least 30% of Canadians are being exposed to higher than acceptable levels of fine particulates. 20 Outdoor air pollution is a factor in one in 12 deaths in major Canadian cities. 21 Approximately 5900 premature deaths occur in Canada s eight largest cities each year due to air pollution. 22 Research suggests that 69% of these deaths come in the form of cardio and cerebrovascular disease. 23 Population studies have found associations between brief increases in outdoor air pollution concentrations and measures of heart disease, including deaths from heart disease as well as heart disease hospitalizations Annotated Bibliography of Recent Studies on the Health Effects of Air Pollution. American Lung Association Environment Canada Environment Canada Ontario Ministry of the Environment Ontario Heart and Stroke Foundation Air Pollution Report Card. 21 Environment Canada Health Canada Ontario Heart and Stroke Foundation Health Canada. 4

5 CLIMATE CHANGE AND HEALTH In 1994, the Ontario Ministry of the Environment predicted that without major efforts to slow the trend of warmer temperatures, we could expect to see more smog episodes in Ontario, increased particulate levels where warmer / drier conditions occur, increased heat-related mortality in large cities such as Toronto, Ottawa and Montreal, and an increased risk of vectorborne viruses. 25 The international scientific community agrees that there has been a significant change in global climate in recent years, particularly in the polar areas, due largely to the burning of fossil fuels for transportation and industrial processes. These activities emit greenhouse gases that trap heat in the atmosphere. 26 There is growing evidence that our climate is changing and that these changes will have significant effects on the health and well-being of citizens in countries throughout the world, including Canada. 27 More frequent and intense heat waves are expected to increase mortality and morbidity Air Quality in Ontario. Ontario Ministry of the Environment Health Canada, Climate Change and Health Office. (2003). Canada's Health Concerns from Climate Change and Variability. Retrieved August 1, 2005, from < 5