Motor vehicle exhaust

EEC Directive on motor vehicle exhaust emission tests... 

Catalytic Converter an air pollution abatement device that removes pollutants from motor vehicle exhaust either by oxidizing them into carbon dioxide and water or reducing them to nitrogen. A typical catalytic oxidizer for auto emission control is illustrated in the sidebar figure. 

Outdoor air is generally less polluted than the system return air. However, problems with reentry of previously exhausted air occur as a result of improperly located exhaust and intake vents or periodic changes in wind conditions. Other outdoor contamination problems include contaminants from other industrial sources, power plants, motor vehicle exhaust, and dust, asphalt vapors, and solvents from construction or renovation. Also, heat gains and losses through the building envelope due to heat conduction through exterior walls, floor, and roof, and due to solar radiation and infiltration, can be attributed to effects from external sources. 

Carbon monoxide (CO) Is one of the most widely distributed air pollutants. It Is formed by natural biological and oxidation processes, the Incomplete combustion of carbon-containing fuels and various Industrial processes. However, the largest Individual source of man-made emissions Is motor vehicle exhausts which account for virtually all CO emitted In some urban environments. It has been estimated that global man-made emissions range from 300-1600 million tons per year, which Is approximately 60% of the total global CO emissions (22-23). 

Catalytic treatment of motor vehicle exhaust has been applied in all passenger cars in the USA since the 1975 models. The first cars with electronic feedback systems and three-way catalysts were 1979 Volvos, sold in California. Today all new gasoline cars sold in the Western world are equipped with catalytic converters. It... 

Noble, W. M. The Relation of Plant Damage to Fuel Composition. Paper Presented at the Joint Research Conference on Motor Vehicle Exhaust Emissions and Their Effects, Dec. 5, 1%1, University of California, Los Angeles. 11 pp. 

K, Ca, Ti, Fe and Sr. The second factor has high values for bromine and lead. This factor can be identified as motor vehicle exhaust. It does not have a large loading for mass. It would be expected that most of the motor vehicle mass would be found in the fine particle fraction. 

In buildings where motor vehicle exhaust can be entrained from outdoors or attached parking garages, elevated indoor CO levels may also result (e.g., Hodgson et al., 1991). 

In Sweden, three-way catalysts have been required on all cars since 1989, and tax incentives were offered to purchase such vehicles in the 1987 and 1988 model years. Figure 16.34 shows the CO and hydrocarbon exhaust emissions as a function of model year of gasoline-powered cars, measured using a remote-sensing technique (Sjodin, 1994). There is a large decrease in the emissions from 1987 to 1988 and 1989, supporting the effectiveness of these motor vehicle exhaust controls. 

Storm water runoff from cities and villages presents another problem. This runoff contains salts from road deicing, street refuse, animal waste, food litter, residue from atmospheric deposition of sulfuric and nitric acid, metals, asbestos from automobile brakes, rubber from tires, hydrocarbons from motor vehicle exhaust condensates, oil and grease, soil and inorganic nutrients from construction sites, and a variety of other chemicals. Research shows a heavy impact of urban nonpoint pollution on freshwater quality (World Resources Institute, 1988). 

Toluene is released into the atmosphere principally from the volatilization of petroleum fuels and toluene-based solvents and thinners and in motor vehicle exhaust. It is also present in emissions from volcanoes, forest fires and crude oil. It has been detected at low levels in surface water, groundwater, drinking-water and soil samples (United States National Library of Medicine, 1997). 

Jo W-K, Song K-B (2001) Exposure to volatile organic compounds for individuals with occupations associated with potential exposure to motor vehicle exhaust and/or gasoline vapor emissions. Sci Total Environ 269(l-3) 25-37... 

Maricq, M.M., Podsiadlik, D.H. and Chase, R.E. (2000) Size distribution of motor vehicle exhaust PM a comparison between ELPI and SMPS measurements. Aerosol Science and Technology, 33, 239-60. 

Owing to their greater exposure to motor vehicle exhaust emissions, it is possible that fatty foods on sale at shops attached to petrol stations or at stalls and shops in busy roads could contain higher concentrations of aromatic hydrocarbons than similar foods on sale at other shops. A study in Germany found that concentrations of benzene and toluene were higher in retail packs from petrol stations on busy roads than from petrol stations in rural areas.15 It also found that retail packs from shops in busy roads contained higher concentrations of benzene, toluene, xylenes and ethylbenzene than retail packs from shops in residential areas. 

Van Vliet P, Knape M, de Hartog J, Janssen N, Harssema H, Brunekreef B (1997) Motor vehicle exhaust and chronic respiratory symptoms in children living near freeways. Environ Res, 74 122-132. 

Ambient air samples from 44 sites in 39 U.S. urban areas were collected from 6 a.m. to 9 a.m. during June through September of 1984, 1985, and 1986. Benzene was present in every sample. The median benzene site concentrations ranged from 4.8 to 35 ppb, with the overall median being 12.6 ppb (detection limit = 0.04 ppb). The data indicated that mobile sources were the major source of benzene in the vast majority of samples (EPA 1987e). In California, motor vehicle exhaust and motor vehicle evaporation accounted for 79.8% of the population exposure to ambient benzene (Allen 1987). The 1984 population-weighted average benzene concentration in California was estimated to be 3.3 ppb (Allen 1987). 

Wolff SP. 1992. Correlation between car ownership and leukaemia is non-occupational exposure to benzene from petrol and motor vehicle exhaust a causative factor in leukaemia and lymphoma Experientia 48(3) 301-304. 

Carbon monoxide ( = CO) (carbon monoxide) used for execution of criminals by Romans Greeks biggest gaseous cause of human death > 6% motor vehicle exhaust Corossolin (tetrahydrofuran acetogenin) 4-Deoxyasimicin (alkyl tetrahydrofuran) 4-Deoxybullatacin (alkyl tetrahydrofuran)... 

From incomplete combustion of carbon-containing compounds brain neurotransmitter formed by heme oxygenase (HO) type H02 motor vehicle exhaust CO used in mass murder of Jews in Second World War SS Einsatzgruppen mobile gas chambers... 

Olefins, C2-C6 Photochemical degradation emissions refinery emissions Motor vehicle exhaust diesel... 

Aromatic organic material Insignificant Motor vehicle exhaust ... 

Gordon Larson who succeeded McCabe continued to reduce the emissions of refineries and other industries. He also undertook the control of emissions from open dump burning and backyard incinerators and made the initial contacts with the automobile industry to control motor vehicle exhaust emissions. However, in this drive to control the proved main sources of air pollution, Larson was opposed by the petroleum, chemical, and other industries, and primarily the individual citizen with his backyard incinerator. 

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