Vehicle Emissions and Effects on Air Quality: Indoors and Outdoors

Abstract

Vehicle emissions of non-regulated volatile organic compounds (VOCs), such as benzene, can form a major contribution to pollution of the indoor as well as the outdoor environment. Several of these compounds are considered to be a health risk and are important factors in the production of photochemical smog. The introduction of unleaded and particularly 'super unleaded' fuels has significantly increased levels of aromatic compounds in petrol world-wide and has led to changes in fuel composition with respect to olefins and the use of oxygenates. Increased aromatics, olefins and other compounds in fuels used in vehicles not fitted with catalytic converters have been shown to increase emissions of benzene, 1,3-butadiene and other VOCs as well as contributing to increases in photochemical smog precursors. Increases in VOC levels in ambient air clearly produce increased indoor air pollution, particularly in nat urally ventilated buildings.