Stantec Consulting Ltd. St. John's, Newfoundland, Canada.
Sci Total Environ. 2011 Dec 15;412-413:132-7. doi: 10.1016/j.scitotenv.2011.10.037. Epub 2011 Nov 12.
The purpose of this study was to conduct an ecological risk assessment (ERA) for meadow voles (Microtus pennslvanicus) found at three arsenic contaminated sites in Nova Scotia, Canada (as well as two background locations) and to compare the numeric results to measured biomarkers of exposure and effect. The daily intake of arsenic by meadow voles was determined by three separate calculations: estimated daily intake (EDI), bioaccessible estimated daily intake (BEDI, with bioaccessibility of soil included), and actual daily intake (ADI, which is calculated with arsenic concentrations in the stomach contents). The median bioaccessibility of arsenic in soils from the contaminated locations was significantly greater than at background locations. The bioaccessible arsenic concentration in soil from all samples (both contaminated and background) was significantly less than the total concentration. Use of site-specific bioaccessibility (hazard quotients=38 at Upper Seal Harbour (USH); 60 at Lower Seal Harbour (LSH); and 120 at Montague tailings (MONT)) and stomach arsenic contents (hazard quotients=2.1 at USH; 7.9 at LSH; and 6.7 at MONT) in the ERA resulted in lower numeric risk than compared to risk calculated with 100% bioavailability (hazard quotient=180 at USH; 75 at LSH; and 680 at MONT). Further, the use of bioaccessibility on the calculation of risk was aligned with biomarker results (changes in glutathione and micronucleated erythrocytes) in voles captured at the sites. This study provides evidence that using site-specific bioaccessibility in ERAs may provide a more realistic level of conservatism, thereby enhancing the accuracy of predicting risk to wildlife receptors. Furthermore, when numeric risk assessments are combined with site-specific biological data (i.e., biomarkers of exposure and effect), both lines of evidence can be used to make informed decisions about ecological risk and site management.
本研究旨在对加拿大新斯科舍省三个砷污染地点（以及两个背景地点）发现的草原田鼠（Microtus pennslvanicus）进行生态风险评估（ERA），并将数值结果与暴露和效应的测量生物标志物进行比较。通过三种单独的计算方法确定草原田鼠的砷日摄入量：估计日摄入量（EDI）、可生物利用的估计日摄入量（BEDI，包括土壤的可生物利用性）和实际日摄入量（ADI，这是根据胃内容物中的砷浓度计算得出的）。污染地点土壤中砷的中位生物可利用性明显高于背景地点。所有样本（污染和背景）土壤中可生物利用的砷浓度明显低于总浓度。使用特定地点的生物可利用性（危险商数=Upper Seal Harbour（USH）的 38；Lower Seal Harbour（LSH）的 60；和 Montague 尾矿（MONT）的 120）和胃中砷含量（危险商数=USH 的 2.1；LSH 的 7.9；和 MONT 的 6.7）进行 ERA 导致的数值风险低于与 100%生物利用度（危险商数=USH 的 180；LSH 的 75；和 MONT 的 680）相比的风险。此外，在计算风险时使用生物可利用性与在这些地点捕获的田鼠的生物标志物（谷胱甘肽和微核红细胞的变化）结果一致。本研究提供了证据，表明在 ERA 中使用特定地点的生物可利用性可能提供更现实的保守水平，从而提高对野生动物受体风险预测的准确性。此外，当数值风险评估与特定地点的生物数据（即暴露和效应的生物标志物）相结合时，这两种证据都可以用于对生态风险和场地管理做出明智的决策。
