Benzene environmental tobacco smoke

The California Air Resources Board has prepared risk assessments for a number of toxic airborne compounds and mixtures, designated as toxic air contaminants, TACs (Table 16.15). For example, risk assessments for individual compounds such as benzene, benzo[a]pyrene (see Chapter 10), formaldehyde, and vinyl chloride have been carried out, in addition to complex mixtures such as diesel exhaust (California Air Resources Board, 1997a) and environmental tobacco smoke (California Environmental Protection Agency, 1997). These risk assessment documents form the basis for controls imposed as part of the risk management process (e.g., see Seiber, 1996). 

Adlkofer F, Scherer G, Conze C, et al. 1990. Significance of exposure to benzene and other toxic compounds through environmental tobacco smoke. J Cancer Res Clin Oncol 116(6) 591-598. 

While the number of particles is important as they are related to health effects, so too is the size, shape, material properties and chemical composition. Chemicals absorbed or adsorbed into the particles may also have different toxicological effects. In addition to carbon particles and polycyclic aromatic hydrocarbons (PAHs), indoor air can accumulate environmental tobacco smoke as well as chemicals such as biocides, formaldehyde, and volatile organic compounds (VOCs) classified by the International Agency for Research on Cancer (lARC) as carcinogenic (benzene, 1,3-butadiene) (lARC 1995). Since children are the most affected by chronic household exposure, they may be at higher risk of cancer. It was demonstrated a relative increase in leukaemia and lymphoma caused by indoor VOCs as well as by the... 

Scherer G, Ruppert T, Daube H, et al. 1995. Contribution of tobacco smoke to environmental benzene exposure in Germany. Environ Int 21(6) 779-789. 

It should be noted that workers exposed to benzene by dermal contact also may inhale vapors and thus receive a dual exposure. The air in many polluted areas often contains significant benzene levels as a result of the combustion of petroleum fuels. The ambient air over Los Angeles, California, in the decade 1990-2000, for example, typically contained greater than 1.0 ppm benzene.I18 Tobacco smokers and those exposed to secondhand (or environmental) smoke are further exposed to benzene. It is reasonable to anticipate that benzene-containing solvents will be used in urban and industrial areas where the air is polluted with benzene and that smokers will be among those who use such solvents. Such conditions further dictate the need for lowering the allowable benzene concentration in solvents. 

Polycyclic aromatic hydrocarbons (PAHs) represent a class of compounds that contain two or more fused benzene rings. They are environmental pollutants and the most ubiquitous, benzo[a]pyrene (B[a]P), has been upgraded by the International Agency for Research on Cancer to a Group 1 or known human carcinogen [1]. PAHs are products of fossil fuel combustion they are a component of fine particulate matter (size 2.5pm) and as a consequence contaminate the air we breathe, the soil and water supply, and enter the food chain [2, 3]. They are also introduced artificially into smoked, cured, and barbecued food [4, 5], Finally, they are present as a complex mixture in tobacco smoke and second-hand smoke, and are suspect causative agents in human lung cancer [6]. 

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