2005－2020年广西近岸海域表层沉积物重金属含量特征及风险评价

为了了解近15年来广西近岸海域表层沉积物的环境质量状况，本研究应用2005－2020年广西近岸海域表层沉积物重金属数据，运用统计、相关分析、因子分析及风险评价等方法，对广西近岸海域表层沉积物的重金属含量特征、变化趋势及生态风险进行了分析。分析结果表明:2005－2020年，广西近岸海域表层沉积物99.0%的As、98.1%的Cu、99.0%的Pb、99.6%的Cd、100%的Hg、97.9%的Zn、100%的Cr含量低于《海洋沉积物质量标准》（GB 18668—2002）的一类标准限值要求，且58%的站位沉积物重金属含量近15年来无统计意义上的年际变化。地累积指数评价结果显示，广西近岸海域约37.5%的站位表层沉积物存在轻度?中度污染，Hg、As及Cd是主要污染因子；潜在生态风险指数评价结果显示，广西近岸海域表层沉积物重金属总体处于低风险状态。

Assessment on the pollution and risk of heavy metals in surface sediments of Guangxi offshore from 2005 to 2020

The monitoring data of heavy metals in surface sediments from 2005 to 2020 were analyzed in order to discriminate the quality of sediments environmental in Guangxi offshore. In this study, statistical methods, correlation analysis, factor analysis and risk assessment were introduced to analyze the characteristics, trends and ecological risks of heavy metals in surface sediments in Guangxi offshore. The results indicate that approximately 99.0% As, 98.1% Cu, 99.0% Pb, 99.6% Cd, 100% Hg, 97.9% Zn and 100% Cr of monitoring data met the first grade sediment quality of China between 2005 and 2020, and the sediment heavy metal indicators of 58% of the stations have no statistically significant inter-annual changes in the past 15 years. The evaluation results of geo-accumulation index show that about 37.5% of monitoring station in the Guangxi offshore have mild to moderate pollution, and Hg, As and Cd were the main pollution factors. The evaluation results of the potential ecological risk index show that the surface sediments in Guangxi offshore are generally in a low-risk state.