The Environmental Impact of Vehicle Emissions From: Illinois epa
The net result is a modest reduction in each automotive pollutant except lead, for which aggregate emissions have dropped by more than 95 percent
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The net result is a modest reduction in each automotive pollutant except lead, for which aggregate emissions have dropped by more than 95 percent.From Wikipedia, the free encyclopediaList the following sources of emissions must be considered: Life cycle emissions: These are produced in activities associated with the manufacturing, maintenance, and disposal of the automobile and include such items as: Manufacturing plant power requirements Volatile solvents utilized in the manufacturing process (auto paint finishes, etc) Outgassing of synthetic materials utilized to reduce weight and simplify manufacturing Maintenance requirements such as oil and filter changes, battery replacement, etc. Disposal requirements including contaminated lubricants, tires, heavy metals, and landfill Heath Effects of Pollution from Vehicle Engines Research indicates that approximately 3,700 premature deaths and thousands of medical emergencies are linked to air pollution in the greater metropolitan Chicago and East St. Louis areas each year. Carbon monoxide and hydrocarbons are the two main exhaust gases produced by the combustion process in gasoline powered vehicles. Carbon monoxide is a colorless, odorless, toxic gas. It is a by-product of incomplete combustion. Motor vehicles produce more than two-thirds of the man-made carbon monoxide in the atmosphere. Carbon monoxide reduces the volume of oxygen that enters the bloodstream and can slow reflexes, cause drowsiness, impair judgment and vision and even cause death. Hydrocarbons are unburned fuel vapors. When hydrocarbons and other pollutants are exposed to sunlight, a chemical reaction occurs that produces ground-level ozone (smog), which is harmful to our health and the environment. Vehicles are responsible for about 50 percent of the emissions that form ozone. Nitrogen oxides, like hydrocarbons, are precursors to the formation of ozone. They also contribute to the formation of acid rain. What is Ozone? Ozone is a form of molecular oxygen that consists of three oxygen atoms linked together. Ozone in the upper atmosphere (the "ozone layer") occurs naturally and protects life on earth by filtering out ultraviolet radiation from the sun. Ozone at ground level is a noxious pollutant. It is the major component of smog and presents this country's most intractable urban air quality problem. Ozone is a severe irritant. It is responsible for the choking, coughing, and stinging eyes associated with smog. Ozone damages lung tissue, aggravates respiratory disease, and makes people more susceptible to respiratory infections. Children are especially vulnerable to ozone's harmful effects, as are adults with existing disease. Even otherwise healthy individuals may experience impaired health from breathing ozone-polluted air. Elevated ozone levels also inhibit plant growth and can cause widespread damage to crops and forests. Ozone is not emitted directly. It is formed in the atmosphere through a complex set of chemical reactions involving hydrocarbons, oxides of nitrogen, and sunlight. The rate at which the reactions proceed is related to both temperature and intensity of the sunlight. Because of this, problematic ozone levels occur most frequently on hot summer afternoons. Hydrocarbons and nitrogen oxides come from a great variety of industrial and combustion processes. In typical urban areas, at least half of those pollutants come from cars, buses, trucks, and off highway mobile sources such as construction vehicles and boats.
Ozone levels in many cities have come down with the introduction of lower volatility gasoline and as newer cars with improved emission control systems replaced older models. Although there has been significant progress since 1970 in reducing emissions per mile traveled, the number of cars on the road -- and the miles they travel -- almost doubled in the same time frame. In the ten years from 1991 to 2001, fuel sold and vehicle miles traveled increased about 25 percent. Increased sales of sport utility vehicles and trucks also contribute to the problem. Sales of SUVs and light trucks have increased 270 percent since 1976. In 2001, SUVs and trucks overtook cars in sales, and accounted for almost 55 percent of the vehicles sold in 2003. However, these vehicles won’t have to meet passenger car emissions standards until model year 2004. A second reason that ozone levels remain high is that emission control systems do not always perform as designed over the full useful life of the vehicle. Routine aging and deterioration, poor maintenance, and tampering with emission control devices can all increase vehicle emissions. In fact, a major portion of ozone forming hydrocarbons can be attributed to a relatively small number of "super dirty" cars whose emission control systems are not working properly. Unless we dramatically reduce the amount of pollution vehicles emit in actual use, or drastically cut back on the amount we drive, smog free air will continue to elude us.
Source: Ontario Minister of the EnvironmentWhat is fine particulate matter?Particulate matter is characterized according to size - mainly because of the different health effects associated with particles of different diameters. Particulate matter is the general term used for a mixture of solid particles and liquid droplets in the air. It includes aerosols, smoke, fumes, dust, ash and pollen. The composition of particulate matter varies with place, season and weather conditions. Fine particulate matter is particulate matter that is 2.5 microns in diameter and less. It is also known as PM2.5 or respirable particles because it penetrates the respiratory system further than larger particles. PM2.5 in Ontario is largely made up of sulphate and nitrate particles, elemental and organic carbon and soil. What are the sources of fine particulate matter?PM2.5 material is primarily formed from chemical reactions in the atmosphere and through fuel combustion (e.g., motor vehicles, power generation, industrial facilities residential fire places, wood stoves and agricultural burning). Significant amounts of PM2.5 are carried into Ontario from the U.S. During periods of widespread elevated levels of fine particulate matter, it is estimated that more than 50 per cent of Ontario's PM2.5 comes from the U.S.
Notes:Transportation, wood burning, utility/commercial fuel combustion, plus secondary organic aerosols formed from precursor VOC emissions. Formed from NOx emitted from regional and local sources: transportation, utilities, and industries. Fugitive dust (paved roads, construction), and industries. Formed from SO2 and SO4 emitted from regional and local sources: oil and coal-fired utility and commercial/industrial boilers, small combustion sources, transportation, smelters. Directory: ~garrick ~garrick -> Sustainability and Cities: Overcoming Automobile Dependence ~garrick -> 4. Multimodal Transportation and Sustainability Download 245.47 Kb. Share with your friends:
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