School of Environmental and Science and Engineering, Huazhong University of Science and Technology, Wuhan, China.
Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, China.
PLoS One. 2018 Oct 4;13(10):e0205026. doi: 10.1371/journal.pone.0205026. eCollection 2018.
This study was initiated to document information on the levels of sediment contamination with organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs). Moreover, it was intended to identify compounds which impose major ecological risks to aquatic organisms. Surficial sediments were collected from 46 locations within the streams and rivers of the Awash River Basin. In total 30 compounds were included in this study: 16 OCPs, 7 PCBs and 7 PBDEs. The total concentrations of OCPs, PCBs, and PBDEs ranged from 6.63 to 206.13 ng g-1- dry weight (dw), 0.85 to 26.56 ng g-1-dw and 3.71 to 18.95 ng g-1-dw respectively. Out of all the tested OCPs, heptachlor, heptachlor epoxide, p,p'-dichlorodiphenyltrichloroethane (p,p'-DDT) and β-hexachlorocyclohexane (β-HCH) were the most abundant in the study area. The ratio of (β-HCH/∑HCHs) indicated that HCHs were originally from earlier usage of HCH in the area whereas the ratio of (p,p'-DDT/p,p'-DDE) showed that the majority of DDT components were recently introduced into most of the sampling locations. Even though there were relatively low concentrations of PBDEs and PCBs across the sampling sites, substantial amounts of PCBs were observed in Addis Ababa City. According to the established ecological risk indices, p,p'-DDT and γ-HCH are the major concerns for potential adverse ecological impacts. This study provided the first comprehensive information on organohalogenated compounds' (OCs') occurrences, spatial distributions, and ecological risks in sediments of the Awash River Basin. Thus, the report will be very useful background information for further studies on sediment contamination with OCs' in the region. It also adds important first-hand data to the field of fresh water ecology and provides useful empirical evidence for setting pollution control priorities for an ecologically important, yet largely understudied region.
本研究旨在记录奥克氯苯（OCPs）、多氯联苯（PCBs）和多溴二苯醚（PBDEs）在沉积物中的污染水平，并确定对水生生物构成主要生态风险的化合物。在 Awash 河流域的溪流和河流中，从 46 个地点采集了表层沉积物。本研究共包括 30 种化合物：16 种 OCPs、7 种 PCBs 和 7 种 PBDEs。OCPs、PCBs 和 PBDEs 的总浓度范围分别为 6.63 至 206.13ng g-1-干重（dw）、0.85 至 26.56ng g-1-dw 和 3.71 至 18.95ng g-1-dw。在所测试的所有 OCPs 中，七氯、七氯环氧化物、p,p'-滴滴涕（p,p'-DDT）和β-六氯环己烷（β-HCH）在研究区域内最为丰富。（β-HCH/∑HCHs）比值表明 HCHs 最初来自该地区早期使用 HCH，而（p,p'-DDT/p,p'-DDE）比值表明 DDT 成分主要是最近引入到大多数采样点的。尽管在采样点之间存在相对较低浓度的 PBDEs 和 PCBs，但在亚的斯亚贝巴市观察到大量的 PCBs。根据既定的生态风险指数，p,p'-DDT 和γ-HCH 是对潜在不利生态影响的主要关注。本研究提供了 Awash 河流域沉积物中有机卤代化合物（OCs）的发生、空间分布和生态风险的综合信息。因此，该报告将为该地区进一步研究 OCs 沉积物污染提供非常有用的背景信息。它还为淡水生态学领域增加了重要的第一手数据，并为确定具有重要生态意义但研究不足的地区的污染控制优先事项提供了有用的经验证据。
