health and safety plan solid waste management unit assessment

AUTOMOTIVE GASOLINE 65-20
higher. At one high-volume station, the mean concentration to which an
individual filling his own tank of gas was exposed (for ten minutes)
was 4.2 ppm (2283).
65.3 HUMAN HEALTH CONSIDERATIONS
65.3-l Animal Studies
65.3.1.1 Carcinogenicity
Most of the evidence regarding carcinogenicity of gasoline has
been provided by a study conducted for the American Petroleum Institute
(API) (2298). Reports of this study appear in several forms throughout
the literature. A chronic inhalation study of gasoline vapor was
conducted in mice and rats; the gasoline employed was unleaded, with
the benzene content adjusted to 2%. Groups of both sexes of B6C3Fl
mice and Fischer 344 rats were exposed to vapor at concentrations of
67, 292 or 2056 ppm for 6 hours per day, 5 days per week for periods
ranging from 103 to 113 weeks. After as little as three months of
exposure to 2056 ppm, macroscopic laslons were evident in the kidney of
male rats. Microscopic observations included an increased incidence of
renal disease with tubular degeneration, regeneration or cystic
dilatation among males exposed to 292 or 2056 ppm. At 24 months, an
increase in the occurrence of primary renal neoplasm was seen in the
male rats at all doses, with some evidence of a dose-response relationship.
In addition, a compound related increase in liver nodules and
masses was seen in female mice exposed to the intermediate and high
levels. Histopathologic examination revealed primary hepatocellular
tumors (adenomas and carcinomas) in these animals.
These unexpected findings of species and sex-specific carcinogenic
effects were not evident until late in the study. To better understand
the significance co human health, the American Petroleum Institute contracted
width Universities Associated for Research and Education in
Pathology, Inc. (UAREP) for assistance in interpretation of the findings
. The UAREP reviewed the chronic inhalation study, "old rat
nephropathy" syndrome, and the basic morphological and functional
similarities and differences in the kidneys of the rat, mouse, and man
(2299). This review cone luded that the significance of the
hepatocellular carcinoma in female mice was questionable. The UAREP
felt that other studies on different hydrocarbons demonstrated acute
toxic effects on the female liver including fatty metamorphosis whereas
these effects were not reported in the API chronic inhalation study.
'The finding of renal carcinoma In male rats was clearly
significant. The lesions were seen as early as 90 days and were
dose-related. The lesions could be clearly distinguished from the old
rat nephropathy, which is composed of chronic lesions involving all
components of the kidney, However, administration of unleaded gasoline
appeared to accentuate all the lesions characteristic of old rat
nephropathy. It was not possible to evaluate the potential role of the
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