Sanderson J T, Elliott J E, Norstrom R J, Whitehead P E, Hart L E, Cheng K M, Bellward G D
Division of Pharmacology and Toxicology, Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, Canada.
J Toxicol Environ Health. 1994 Apr;41(4):435-50. doi: 10.1080/15287399409531855.
The Canadian Wildlife Service monitors levels of polychlorinated aromatic hydrocarbons in great blue heron (Ardea herodias) eggs in British Columbia as indicators of environmental contamination. The present project assessed the temporal effects of environmental contamination with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and other polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), and biphenyls (PCBs) on hepatic microsomal ethoxyresorufin O-deethylase (EROD) activities and several morphological parameters in heron hatchlings. Between 1990 and 1992, eggs were collected from two great blue heron colonies in British Columbia that had elevated levels of contamination in 1988: Vancouver in 1990 and 1992, and Crofton in 1991. Biological parameters in the hatchlings and chemical contaminant levels in matched eggs from the same clutch were measured and compared with the findings from the same colonies studied in 1988. Levels of TCDD and other PCDDs and PCDFs had decreased significantly in both colonies since 1988. A concomitant decrease in EROD activity and incidence of chick edema, increase in body weight, and improvement of the reproductive success of the Crofton colony was observed. Body, yolk-free body, stomach, and intestine weights, tibia wet, dry, and ash weights, and tibia length regressed negatively on TCDD level (p < .01; n = 54). Hepatic EROD activity regressed positively on TCDD level (r2 = .49; p = .00005; n = 54). Regression of these parameters on the sum of TCDD toxic equivalents (TEQ) resulted in similar relationships. The reduction in severity of the effects observed in the contaminated colonies in the recent collections, accompanied by the declines in levels of PCDDs and PCDFs, was consistent with the dose-response relationships determined in 1988.
加拿大野生动物服务局监测不列颠哥伦比亚省大蓝鹭（苍鹭）卵中多氯代芳烃的含量，以此作为环境污染的指标。本项目评估了2,3,7,8 - 四氯二苯并 - p - 二恶英（TCDD）以及其他多氯代二苯并 - p - 二恶英（PCDDs）、二苯并呋喃（PCDFs）和联苯（PCBs）对苍鹭幼雏肝脏微粒体乙氧基异吩恶唑酮 - O - 脱乙基酶（EROD）活性和若干形态学参数的时间效应。1990年至1992年期间，从不列颠哥伦比亚省两个大蓝鹭栖息地收集卵，这两个栖息地在1988年污染水平较高：1990年和1992年的温哥华，以及1991年的克罗夫顿。测量了幼雏的生物学参数以及同一窝匹配卵中的化学污染物含量，并与1988年对同一栖息地的研究结果进行比较。自1988年以来，两个栖息地的TCDD以及其他PCDDs和PCDFs含量均显著下降。观察到克罗夫顿栖息地的EROD活性降低、雏鸡水肿发生率降低、体重增加以及繁殖成功率提高。雏鸡的体重、去卵黄体重、胃重和肠重、胫骨湿重、干重和灰重以及胫骨长度与TCDD水平呈负相关（p < .01；n = 54）。肝脏EROD活性与TCDD水平呈正相关（r2 = .49；p = .00005；n = 54）。这些参数与TCDD毒性当量（TEQ）总和的回归分析得出了类似的关系。近期采集样本中，受污染栖息地观察到的效应严重程度降低，同时伴随着PCDDs和PCDFs含量下降，这与1988年确定的剂量 - 反应关系一致。
