近岸海域典型水体中镉的水生态风险评估

为了解我国近岸海域重金属污染现状,以镉为目标污染物,选择北部湾、渤海湾、杭州湾、辽东湾、闽江口、珠江口、长江口、黄河口等8个典型海湾、河口区域作为评估目标区域进行水生态风险评估。研究结果显示:北部湾、渤海湾、杭州湾、闽江口、长江口、珠江口、黄河口等7个海域水体中镉的暴露水平较低,从2005至2013年其急、慢性暴露的最高潜在影响比例均低于5%,且整体呈下降趋势。辽东湾水体中镉从2005至2013年对水生生物的最高潜在影响比例为28.67%(95%置信区间26.29%~30.06%),5%、10%、15%、20%超过率对应的潜在影响比例分别为18.95%(17.84%~20.23%)、12.51%(11.65%~13.61%)、8.26%(7.40%~9.15%)、5.45%(4.62%~6.16%),其在2005—2010年间呈现略微上升趋势,2010—2013年间呈现下降趋势。水体中镉暴露水平主要受入海河流污染物输入的影响,其中五里河、大凌河影响最强。

Ecological Risk Assessment of Cadmium in Chinese Typical Offshore Marine Environment

Probabilistic assessments method was used to assess the ecological risk of cadmium in 8 Chinese typical offshore marine environment including Beibu Gulf, Bohai Bay, Hangzhou Bay, Liaodong Bay, Minjiang Estuary, Pearl Estuary, Huanghe Estuary, Yangtze Estuary. The results showed that there have low risk of cadmium in Beibu Bay, Bohai Bay, Hangzhou Bay, Yangtze Estuary, Minjiang Estuary, Pearl River Estuary, Huanghe Estuary. The highest potential affected fractions (PAF) of acute and chronic toxicity were lower than 5%, and overall potential for adverse effects decreased . The PAF of cadmium in Liaodong Bay is relative high, the highest PAF is 28.67% (with 95% confidence interval of 26.29%-30.06%), and the PAF corresponding to exceedance of 5%, 10%, 15%, 20% are 18.95% (17.84%-20.23%), 12.51% (11.65%-13.61%), 8.26% (7.40%-9.15%), 5.45% (4.62%-6.16%), respectively. The overall trend of cadmium concentration in Liaodong Bay is increasing from 2005-2010 and then declining from 2010-2013. It also indicated that the Wuli River and Daling River were main pollution source in the Liaodong Bay.