Custer Thomas W, Custer Christine M, Goatcher Buddy L, Melancon Mark J, Matson Cole W, Bickham John W
U.S. Geological Survey, Upper Midwest Environmental Sciences Center, 2630 Fanta Reed Road, La Crosse, WI 54603, USA.
Environ Monit Assess. 2006 Oct;121(1-3):543-60. doi: 10.1007/s10661-005-9153-x. Epub 2006 Jun 9.
Current and historical point source discharges, storm water runoff, and accidental spills have contaminated the water, sediment, and biota within the Calcasieu Estuary in southwestern Louisiana. In 2003, barn swallow (Hirundo rustica) eggs and nestlings were collected beneath two bridges that cross Bayou d'Inde, the most contaminated waterway within the Calcasieu Estuary. Samples were also collected from a bridge over Bayou Teche, a reference site in south central Louisiana. Polychlorinated biphenyl (PCB) concentrations in barn swallow eggs and nestlings were significantly higher at the downstream site on Bayou d'Inde (2.8 micro g/g PCBs in eggs and 1.5 micro g/g PCBs in nestlings) than at the other two sites (< 0.2 micro g/g PCBs in eggs and nestlings at both sites). Ethoxyresorufin-O-dealkylase activity in nestling livers was significantly higher at the downstream site on Bayou d'Inde (50 pmol/min/mg) compared to the other two locations (24 pmol/min/mg, each), probably because of exposure to PCBs. Polychlorinated dibenzo-p-dioxin and polychlorinated dibenzofuran concentrations in eggs and polycyclic aromatic hydrocarbons in nestlings were at background concentrations at all sites. Trace element concentrations in barn swallow eggs and nestling livers were at background levels and did not differ among the three sites. A biomarker of DNA damage did not differ among sites.
当前及历史上的点源排放、雨水径流和意外泄漏已污染了路易斯安那州西南部卡尔卡苏河口内的水体、沉积物和生物群。2003年，在卡尔卡苏河口内污染最严重的水道——印第安湾上的两座桥下方收集了家燕（Hirundo rustica）的卵和雏鸟。还从路易斯安那州中南部的一个参考地点——特谢湾上的一座桥上采集了样本。印第安湾下游地点家燕卵和雏鸟中的多氯联苯（PCB）浓度（卵中为2.8微克/克PCB，雏鸟中为1.5微克/克PCB）显著高于其他两个地点（两个地点的卵和雏鸟中均<0.2微克/克PCB）。与其他两个地点（均为24皮摩尔/分钟/毫克）相比，印第安湾下游地点雏鸟肝脏中的乙氧基异吩唑酮 - O - 脱烷基酶活性显著更高（50皮摩尔/分钟/毫克），这可能是由于接触了多氯联苯。所有地点卵中的多氯二苯并 - p - 二恶英和多氯二苯并呋喃浓度以及雏鸟中的多环芳烃浓度均处于背景浓度。家燕卵和雏鸟肝脏中的微量元素浓度处于背景水平，三个地点之间没有差异。各地点之间DNA损伤的生物标志物没有差异。
