Toxicity Evaluation of Exposure to an Atmospheric Mixture of Polychlorinated Biphenyls by Nose-Only and Whole-Body Inhalation Regimens
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- 作者：Xin Hu ; Andrea Adamcakova-Dodd ; Hans-Joachim Lehmler ; Katherine Gibson-Corley ; Peter S. Thorne
- 刊名：Environmental Science & Technology
- 出版年：2015
- 出版时间：October 6, 2015
- 年：2015
- 卷：49
- 期：19
- 页码：11875-11883
- 全文大小：590K
- ISSN：1520-5851
文摘
The health risk of inhalation exposure to polychlorinated biphenyls (PCB) cannot be assessed with high confidence due to the lack of rigorous inhalation studies. One uncertainty rests on exposure regimen, as whole-body exposure systems allow oral PCB intake that confounds the exposure. We conducted contemporaneous PCB inhalation exposures with whole-body and nose-only exposure methods. Female Sprague鈥揇awley rats were concurrently exposed to vapor-phase PCBs (533 卤 93 渭g/m3) generated from PCB11-supplemented Chicago Air Mixture resembling the Chicago airshed, 4 h/day, 6 days/week, for 4 weeks. Congener-specific analysis showed 1.5-fold higher 鈭慞CBs in the lungs of nose-only exposed than the whole-body exposed animals (p = 0.0024). Higher 鈭慞CB concentrations were also found in the sera, livers, brains, and adipose tissue of nose-only exposed animals (1.1鈥?.5-fold), but these increases were not statistically significant. Congener profiles of five tissue types were dominated by PCB 28/31 and higher-chlorinated congeners in both groups reflecting rapid metabolism of other lower-chlorinated PCBs. No toxicity was seen regarding metabolic enzyme expression, glutathione, or histopathology. However, diminished weight gain and reduced plasma total thyroxine levels were found in both groups compared with controls, after exposure to 76 渭g/m3 鈭慞CBs as adjusted for continuous exposure. Hepatic lipid peroxidation was also elevated in the nose-only group. Our study shows that prolonged nose-only exposure was well-tolerated and eliminated the need for housing animals outside the vivarium, thus was preferred for long-term PCB inhalation studies.