广州及周边地区森林土壤As、Se、Hg质量分数特征及污染评价

研究了广州及周边地区5处代表性森林土壤（鼎湖山、西樵山、华南植物园、黄埔和南昆山）As、Se、Hg质量分数特征及污染状况。结果表明,上述5地森林表层土壤As质量分数平均值分别为18.6、18.0、12.2、11.4、26.1 mg.kg-1,Se质量分数平均值分别为0.360、0.729、0.286、0.421、0.434 mg.kg-1,Hg质量分数平均值分别为0.201、0.270、0.139、0.224、0.087 mg.kg-1。除植物园土壤Se质量分数、南昆山土壤Hg质量分数较接近背景值外,5林地As、Se、Hg质量分数均超过背景值,可能存在外源As、Se、Hg输入。其中,南昆山As输入,西樵山Se、Hg输入,黄埔、鼎湖山Hg输入较明显。单因子污染指数分析结果表明在南昆山As为最严重的污染物,而在鼎湖山、植物园、西樵山和黄埔Hg为最严重的污染物。综合污染指数分析结果表明5林地土壤均受到不同程度的污染,其中西樵山土壤属重度污染,南昆山、黄埔、鼎湖山属中度污染,植物园污染较轻,属轻度污染。

Characteristics and pollution assessment of arsenic, selenium and mercury of forest soils in and around Guangzhou region

The present study addressed the spatial patterns and pollution assessment of arsenic（As）,selenium（Se） and mercury（Hg） in soils of five representative forest sites located in Dinghushan natural reserve（DHS） of Zhaoqing,Xiqiaoshan forest park（XQS） of Foshan,suburban South China Botanical Garden（BG） and urban industrially-polluted Huangpu district（HP） of Guangzhou,and remote Nankunshan reserve（NKS） of Huizhou.Mean As concentration in top soils of the forests were 18.6（DHS）,18.0（XQS）,12.2（BG）,11.4（HP） and 26.1（NKS） mg.kg-1.And mean Se and Hg concentration of the corresponding sites were 0.360,0.729,0.286,0.421 and 0.434 mg.kg-1 and 0.201,0.270,0.139,0.224,and 0.087 mg.kg-1,respectively.Soil As,Se,Hg contents were higher than the background values in all the studied sites except for Se in BG and Hg in NKS.These results clearly indicated that external input of As,Se and Hg may occur at most of those sites,particularly with significant input of As in NKS,Se and Hg in XQS,and Hg in HP and DHS.Single factor pollution index analyses indicated that As was the most concerned pollutant in NKS,and Hg in DHS,BG,XQS and HP.According to the comprehensive pollution index analyses,we inferred that XQS was the heavily polluted site,NKS,HP and DHS were moderate ones,and BG was the slightly polluted site.