Laserfiche WebLink
€ s <br /> E: <br /> - L'UM iOTln GASOLINE <br /> camaonents (e.g. , --aphthalene and methyinaphthaleae) b -'_�� d do- <br /> aasttc animals, y an <br /> which may also result in human exposurLr. u-•- <br /> bioccncentratian of these components. to the <br /> I <br /> Grotmd water contaminated with gasoline can lead to inhalation <br /> exposures in homes using this water. In one study of homes in liaise <br /> (2313) , concentrations of total bernzene, toluene and xylene measured in } <br /> 3 air of the closed bathrooms while hot showers were <br /> } 3.15.` and 30 ppm in homes with 6 3 ming were 2.05. <br /> hydrocarbons in their water. In the cwo2 homes with respectively, <br /> che highest. total <br /> concentrations. <br /> xylene accounted for roughly 63% of the concentration <br /> in air, toluene 29-321 and benzene 5.9l; in the other home 95! was <br /> I benzene. the rest taluane. The author of this study suggested that <br /> +s ++ <br /> Odor may be a sensitive indicator of gasoline conra�+.,.s g <br /> n in water. <br /> In the houses with high hydrocarbon contamination, an offensive odor t <br /> vas noticaable, especially during sampling (2313) . Even ' <br /> benzene, toluene or xylane was detected in the air of three house with <br /> i less than 0.5 ppm total hydrocarbons in their vacar, <br /> in two of these <br /> { homes gasoline odors were present in the bathroom. However, a <br /> modelling study (2314) indicates that petroleum-based pollutants <br /> (benzene, toluene, xylene) praaent in water at 5 to 50 ppb--levels <br /> i - below detectable taste, or odor thxeshholds--say result in peak air <br /> concentrations that cause mucous membrane irritation. <br /> Volatilization of gasoline hydrocarbons is soil is anochar <br /> - potential source of human exposure. This exposure pathway is Likelyto <br /> be more significant. for <br /> �` �• �f gasoline than outer petroleea: products because ; <br /> of its high volatility. Exposures may be more intenxive when the soil <br /> L2 contaminated directly from lacking uadergraemd storage casks and <br /> pipes, rather than from surface spills. In such cases, the mora <br /> volatile components do not have as opportunity to evaporate before <br /> I penetrating the soil. Once in the soil. the hydrocarbons evaporate <br /> saturating the air in the soil pores, and diffusing in all diraczions <br /> including upward to the soil, surface. The vapors may diffuse into the <br /> basesene of homes or other st=uctures in the area resulting in <br /> inhalation exposures to the building's occupants. <br /> 65.2.4 Other Sources of Human Exposure <br /> { Data on ambient concentrations of gasoline in air and water as <br /> 'I <br /> well as food and drinking water are not readily available in the <br /> literature. Exposure information on specific components may be found <br /> in other chapters of the IRP Toxicology Guide. <br /> The volatile nature of automotive gasoline suggests chat <br /> Inhalation may represent a si icsur. <br /> gxtsf exposure pathway. The average � <br /> concentrations of automotive gasoline to which residents of ca mmmttias <br /> i <br /> near bulk terminals. bulls plants. and service stations (employing no <br /> i, - special controls) are exposed have been estimated as 1.41, 0.073, 0.026 <br /> ppm. respectively (2311) . It should be emphasized that these values <br /> are •averaged over a lifetime and in all cases Che concentrations are <br /> estimated from emission rates. Exposure to service station employees <br /> and .individuals filling their tanks ac self-service operations are much . <br /> 6/87 <br /> - <br /> 41 <br /> 1 ' ' <br />