Certain base ingredients called precursor gases are used to create ozone that in turn produces smog. Those precursor gases are nitrous oxide (NOX) and volatile organic compounds (VOC). NOx is produced from the combustion of fossil fuel, while volatile organic compounds (VOC) come from the evaporation of gas, paint, oils and solvents.
The fine particles are those that are small enough not to fall on the ground. They are generally under 10 microns (µm) in diameter, which is at least seven times smaller than the width of a hair. The smallest ones (for example, 2.5 µm and under) are the most harmful, because they can penetrate deeply into the lungs, bringing toxic substances with them. One of the chemical chain reactions that happen thanks to these particles is the fabrication of several dangerous secondary pollutants, such as troposphere ozone (O3), or ozone measured at ground level.
Nitrous oxides (NOx) are mainly produced during fossil fuel combustion in spark engines or in the units of certain manufacturing warehouses (such as electricity produced from fossil combustion). In the case of volatile organic compounds (VOC), they originate from motor vehicles, fuel evaporation in gas stations and the use of solvents, paints and oils. While VOC emissions are mainly generated from three activity sectors, which are road transport, industries and heating, they are especially attributable to the transports sector.
As a matter of fact, the inventory of atmospheric pollutant quantities generated from all activity sectors, put together by the ministry of environment in 1999, has revealed that 84% of nitrous oxide (NOx) and 46% of volatile organic compounds (VOC) are produced from the transports sector.
Their effects on health and the environment
It is now a fact that the rise of the number of diseases and deaths related to air pollution is both considerable and irrefutable, according to last 2002 Symposium on air pollution and public heath, organized by the Conference of Governors. The fine particles (MP2.5) and ozone (O3) associated with well-known cardio-respiratory health problems and appear when exposed to concentrations generally found in urban areas. In addition, American epidemic studies (Harvard, American Cancer Society, California Advantists' smog and health study), backed by European studies, associate the appearance of cancer with exposure to ambient air pollution related to road traffic. Furthermore, a study based on 6 American cities and 8 Canadian cities revealed a rise in the daily death rate associated with a daily rise in particles. In the case of ozone, the proof is more and more convincing upon its impact on asthma and other respiratory diseases.
Even healthy adults can develop symptoms if they are exposed to heavy concentrations. Among others, people who have jobs working outside that demand physical effort, or people spending lots of time outside, are more subject to being affected. As a matter of fact, the presence of these substances can cause harmful effects on human health, from a simple cough, eye or mucosa irritation, or conjunctivitis, right up to cancer, immunodeficiency, cardio-vascular diseases, pulmonary tissue damage, asthma, and other pulmonary problems. Finally, health specialists say that these pollutants are the cause of certain premature deaths. In addition to older people and children, those stuck with respiratory and cardio-vascular diseases are especially vulnerable to particle pollution.
Canada-wide, we counted about 5,000 deaths directly related to smog episodes. According to the ministry of Environment, Lands and Parks of British-Columbia (MELP BC, 1995), health costs associated with pollution caused by fine particles in the Fraser valley amounted to between 420 and 900 million dollars, in 1995 only.
In addition to being the source of health problems, smog affects forests, infrastructures and culture, which ends up costing hundreds of millions of dollars in expenses.
The fine particles are those that are small enough not to fall on the ground. They are generally under 10 microns (µm) in diameter, which is at least seven times smaller than the width of a hair. The smallest ones (for example, 2.5 µm and under) are the most harmful, because they can penetrate deeply into the lungs, bringing toxic substances with them. One of the chemical chain reactions that happen thanks to these particles is the fabrication of several dangerous secondary pollutants, such as troposphere ozone (O3), or ozone measured at ground level.
Nitrous oxides (NOx) are mainly produced during fossil fuel combustion in spark engines or in the units of certain manufacturing warehouses (such as electricity produced from fossil combustion). In the case of volatile organic compounds (VOC), they originate from motor vehicles, fuel evaporation in gas stations and the use of solvents, paints and oils. While VOC emissions are mainly generated from three activity sectors, which are road transport, industries and heating, they are especially attributable to the transports sector.
As a matter of fact, the inventory of atmospheric pollutant quantities generated from all activity sectors, put together by the ministry of environment in 1999, has revealed that 84% of nitrous oxide (NOx) and 46% of volatile organic compounds (VOC) are produced from the transports sector.
Their effects on health and the environment
It is now a fact that the rise of the number of diseases and deaths related to air pollution is both considerable and irrefutable, according to last 2002 Symposium on air pollution and public heath, organized by the Conference of Governors. The fine particles (MP2.5) and ozone (O3) associated with well-known cardio-respiratory health problems and appear when exposed to concentrations generally found in urban areas. In addition, American epidemic studies (Harvard, American Cancer Society, California Advantists' smog and health study), backed by European studies, associate the appearance of cancer with exposure to ambient air pollution related to road traffic. Furthermore, a study based on 6 American cities and 8 Canadian cities revealed a rise in the daily death rate associated with a daily rise in particles. In the case of ozone, the proof is more and more convincing upon its impact on asthma and other respiratory diseases.
Even healthy adults can develop symptoms if they are exposed to heavy concentrations. Among others, people who have jobs working outside that demand physical effort, or people spending lots of time outside, are more subject to being affected. As a matter of fact, the presence of these substances can cause harmful effects on human health, from a simple cough, eye or mucosa irritation, or conjunctivitis, right up to cancer, immunodeficiency, cardio-vascular diseases, pulmonary tissue damage, asthma, and other pulmonary problems. Finally, health specialists say that these pollutants are the cause of certain premature deaths. In addition to older people and children, those stuck with respiratory and cardio-vascular diseases are especially vulnerable to particle pollution.
Canada-wide, we counted about 5,000 deaths directly related to smog episodes. According to the ministry of Environment, Lands and Parks of British-Columbia (MELP BC, 1995), health costs associated with pollution caused by fine particles in the Fraser valley amounted to between 420 and 900 million dollars, in 1995 only.
In addition to being the source of health problems, smog affects forests, infrastructures and culture, which ends up costing hundreds of millions of dollars in expenses.