Journal of toxicology and environmental health
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The effects of short-term exposure to ozone on control and elastase-induced emphysematous rats were examined to investigate whether emphysema would change the pulmonary susceptibility to oxidant air pollution. Emphysema was induced in rats after a single intratracheal instillation of 0.2 IU elastase/g body weight. Histologically, panacinar emphysema was apparent at 2, 4, 8, and 16 wk, that is, the total duration of the experiment. ⋯ No differences in MLI as well as in ISA between ozone-exposed rats (with or without emphysema) and their respective controls were observed. Short-term exposure to ozone induced an identical, significant increase in protein content, lactate dehydrogenase, glucose-6-phosphate dehydrogenase, and glutathione peroxidase activities in lungs of normal and emphysematous rats. Moreover, these results strongly suggest that emphysematous rats are not more susceptible to ozone than nonemphysematous rats.
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J Toxicol Environ Health · Jan 1987
Disposition of decabromobiphenyl ether in rats dosed intravenously or by feeding.
The disposition of 14C-labeled decabromobiphenyl ether (DBBE) in male Fischer rats dosed by feeding (0.025-5.0% of the diet) or intravenously (1 mg/kg) was determined. For rats dosed by feeding, intestinal absorption of DBBE was evident in that the intact compound was present in extracts of liver. For these rats, the size of the liver increased with increasing concentration of DBBE in the diet. ⋯ In 4 h, rats with biliary cannulas excreted in the bile 7.17% of the intravenously administered radioactivity; less than 1% was excreted as intact DBBE. Biliary excretion was apparently the major route for elimination of the intravenously administered compound. The rapid excretion and extensive metabolism of DBBE, relative to other polyhalogenated compounds, are advantageous properties that may allow it to be used in place of structurally similar compounds presently employed in industrial applications.
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J Toxicol Environ Health · Jan 1986
Effects of ozone and sulfuric acid aerosol on gas trapping in the guinea pig lung.
Four groups of 20 guinea pigs were sequentially exposed by inhalation to either air followed by sulfuric acid aerosol, ozone followed by sulfuric acid aerosol, ozone followed by air, or air followed by air to determine whether ozone preexposure sensitizes guinea pigs to the airway constrictive effects of sulfuric acid aerosol. All first exposures to ozone or air were 2 h in duration; all second exposures to sulfuric acid or air were for 1 h. All ozone and sulfuric acid exposures were 0.8 ppm and 12 mg/m3, respectively. ⋯ Ozone significantly (p less than 0.05) increased trapped gas volumes, which were 44% (ozone-acid) to 68% (ozone-air) greater than in the air-air group. Trapped gas volume was 23% greater in the ozone-acid group than in the air-acid group, but the difference was not statistically significant (p less than 0.20). Thus, ozone increased gas trapping but did not significantly sensitize guinea pigs to the bronchoconstrictive action of sulfuric acid.
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J Toxicol Environ Health · Jan 1986
Comparative StudyBenzene levels in ambient air and breath of smokers and nonsmokers in urban and pristine environments.
Benzene levels in human breath and in ambient air were compared in the urban area of San Francisco (SF) and in a more remote coastal pristine setting of Stinson Beach, Calif. (SB). Benzene analysis was done by gas chromatography-mass spectroscopy (GC-MS). Ambient benzene levels were sevenfold higher in SF (2.6 +/- 1.3 ppb, n = 25) than SB (0.38 +/- 0.39 ppb, n = 21). ⋯ Of special interest was the finding that benzene in breath of SF nonsmokers (2.5 +/- 0.8 ppb) was greater than that in nonsmokers ambient air (1.4 +/- 0.1 ppb). The same was true in SB, where benzene in nonsmokers breath was greater than ambient air (1.8 +/- 0.2 ppb versus 1.0 +/- 0.1 ppb on d 1 and 1.3 +/- 0.3 ppb versus 0.23 +/- 0.18 ppb on d 2). This suggests an additional source of benzene other than outdoor ambient air.
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J Toxicol Environ Health · Jan 1986
Effects of sulfuric acid mist inhalation on mucous clearance and on airway fluids of rats and guinea pigs.
The responses of guinea pigs and rats to inhaled sulfuric acid aerosols were compared to define species differences and to determine the small-animal model most relevant to human exposures. Rats were exposed for 6 h to 1, 10, and 100 mg H2SO4/m3. Guinea pigs were exposed for 6 h to 1, 10, and 27 mg H2SO4/m3. ⋯ A tendency toward faster clearance was observed at high concentrations of H2SO4 for both guinea pigs and rats (statistically significant only for the rats). The speeding of mucous clearance was correlated with increases in airway sialic acid and also with the appearance of excess tracheal secretions, detected using scanning electron microscopy in both rats and guinea pigs. The responses of guinea pigs to sulfuric acid exposures were more similar to those reported for humans than were those of rats.