Bl. Robinson et al., HEPATIC AND RENAL ASSESSMENT OF ACUTE EXPOSURE TO INHALED EPICHLOROHYDRIN - TOXICOLOGICAL EVALUATION AND EXPOSURE MODELING, Inhalation toxicology, 7(2), 1995, pp. 289-301
To examine the hepatic and renal effects of acute exposure to inhaled
epichlorohydrin (ECH), male F344 rats were exposed either to 0 or 100
ppm ECH by inhalation for 4 h. Hepatic and renal toxicity were assesse
d at the termination of exposure and on days 1, 2, and 3 postexposure.
Exposure to inhaled ECH caused no histopathological evidence of hepat
ic or renal toxicity and had no effect on serum indicators of hepatic
toxicity, or hepatic cytochrome P-450 and glutathione concentrations.
Exposure to inhaled ECH resulted in an increase in relative kidney wei
ght in rats that were either 65 +/- 2 days old or 73 +/- 2 days old on
the day of inhalation exposure (young adult rats) but not in rats tha
t were 96 +/- 2 days old on the day of inhalation exposure (adult rats
), and a decrease in absolute and relative liver weight in adult rats
but not young adult rats. Blood urea nitrogen/creatinine (BUN/CREAT) w
as decreased in young adult rats on day 0, and BUN was slightly increa
sed in adult rats on days 1, 2 and 3. These observations indicate that
acute exposure to 100 ppm ECH did not produce consistent alterations
in indicators of hepatic and renal toxicity. Ambient impact assessment
modeling (AIAM), a methodology for estimation of exposure over short
time periods and comparison of these predicted ambient concentration l
evels to short-term toxicological threshold values, was conducted for
three typical industrial sources of ECH pollution. The results of thes
e analyses illustrated the interdependence of toxicological evaluation
and exposure modeling in short-term noncancer risk assessment and dem
onstrated the usefulness of AIAM in prioritizing chemicals for additio
nal toxicological evaluation.