近年钦州沿海海水、沉积物及牡蛎重金属污染分析和评价

Analysis and evaluation of heavy metals pollution in seawater,sediments and oysters of Qinzhou coastal area in recent years

【目的】综合评价钦州沿海海水、沉积物及牡蛎重金属污染情况,为钦州沿海海域环境保护、牡蛎产业发展及其食用安全提供参考依据。【方法】采用单项污染指数法、综合污染指数法和潜在生态危害指数法对近年钦州沿海海水、沉积物及牡蛎重金属污染进行分析和评价。【结果】2009—2016年钦州沿海海水中Cu、Cd和As均未超标,而Pb和Hg超标较严重。沉积物中仅2010年的Cd和Hg处于中污染程度,其余重金属元素均为低污染程度,各年份沉积物综合污染程度低;2010年Cd和Hg处于较高潜在生态风险,2014年Cd处于中潜在生态风险,沉积物综合潜在生态风险除2010年处于中风险外,其余年份均处于低风险。根据《海洋生物质量标准》评价,钦州沿海牡蛎在2008、2010、2015和2016年受Cu和Cd重度污染;根据《食品安全国家标准食品中污染物限量》评价,牡蛎在2008年受Cd和As及2010年受Cd重度污染。【结论】近来钦州沿海海水主要重金属污染元素是Pb和Hg;沉积物综合污染水平和综合潜在生态风险值低;牡蛎出现重金属污染现象,但污染程度呈下降趋势。今后应加强对钦州沿海海域环境的监测和管理,避免影响海域水产养殖和引发食品安全问题。

【Objective】The purpose of the study was to comprehensively evaluate the heavy metals pollution of seawater,sediments and oysters in Qinzhou coastal area,and provide reference for environmental protection,oyster industry development and food safety in Qinzhou coastal area.【Method】Three methods contained single pollution index,comprehensive pollution index and potential ecological hazard index were used to analyze and evaluate the heavy metals pollution of seawater,sediments and oysters in Qinzhou coastal area in recent years.【Result】In seawater of Qinzhou coastal areas during 2009-2016,Cu,Cd and As in the seawater were not exceeded,but Pb and Hg polluted seriously.Among the sediments,only Cd and Hg were in the middle pollution level in 2010,other heavy metals were in low pollution level;the comprehensive pollution index of sediments was at low pollution level in all years tested.Cd and Hg were in strong potential ecological risk in 2010,Cd was in the middle potential ecological risk in 2014.The comprehensive potential ecological risk was in medium intensity only in 2010,and in low risk in other years.Oysters were heavily polluted by Cu,Cd,Zn according to Marine Biological Quality Standards in 2008,2010,2015 and 2016.Nevertheless,oysters only suffered serious pollution by Cd and As in 2008 and by Cd in 2010 according to the National Food Safety Standards Limit of Pollutants in Foods.【Conclusion】In recent years,the main heavy metals pollution elements in the coastal water of Qinzhou are Pb and Hg,the comprehensive pollution level and comprehensive potential ecological risk index of sediments are low.The oysters have been polluted by heavy metals,but the pollution degree is decreasing.The monitoring and management of the coastal environment in Qinzhou should be strengthened to avoid affecting aquaculture and causing food safety problems in the sea area.