(1. 中南大學(xué) 冶金與環(huán)境學(xué)院，長(zhǎng)沙 410083；
2. 核工業(yè)北京地質(zhì)研究院，北京 100029；
3. 徐州市環(huán)境保護(hù)科學(xué)研究所，徐州 221006)
摘 要: 為了查明洞庭湖濕地周圍表層土壤重金屬污染及其對(duì)人體健康的風(fēng)險(xiǎn)，選擇2016~2018年洞庭湖區(qū)域周圍10個(gè)土壤采樣點(diǎn)，共采集了表層土壤(0~30 m)樣品100份，分析了其中的重金屬含量、分布，并采用地累積指數(shù)法(Igeo)、內(nèi)梅羅指數(shù)法(NI)和土壤健康風(fēng)險(xiǎn)評(píng)價(jià)法等方法進(jìn)行了風(fēng)險(xiǎn)評(píng)價(jià)。結(jié)果表明：土壤樣品中Pb、Cd、Hg、As和Cu 5種重金屬元素的平均濃度分別為53.33、1.62、0.27、26.8和37.72 mg/kg，高于研究區(qū)域土壤環(huán)境背景值。其中Cd、As的平均濃度，西洞庭湖、南洞庭湖和東洞庭湖Cd的濃度和南洞庭湖As的濃度均高于《土壤環(huán)境質(zhì)量標(biāo)準(zhǔn)》(GB 15618—2018)中農(nóng)用地土壤污染風(fēng)險(xiǎn)篩選值的標(biāo)準(zhǔn)。Cd、Hg、As和Cu的最大污染值在南洞庭湖，Pb的最大污染值在東洞庭湖。地累積指數(shù)法(Igeo)研究表明，三年時(shí)間里，Cd處于重度污染水平，Pb、Hg、As處于無污染到中度污染水平。內(nèi)梅羅指數(shù)法(NI)研究表明，三年時(shí)間里，西洞庭湖、南洞庭湖和東洞庭湖都處于輕度污染水平。運(yùn)用土壤健康風(fēng)險(xiǎn)評(píng)價(jià)體系中的無意吸食、皮膚接觸、呼吸接觸3種暴露因素對(duì)人體健康風(fēng)險(xiǎn)的評(píng)估表明：每百萬人口中，平均有13個(gè)成年人和8個(gè)兒童具有癌癥風(fēng)險(xiǎn)。研究結(jié)果為洞庭湖濕地土壤污染的來源和特征提供參考和建議。
關(guān)鍵字: 洞庭湖；土壤；重金屬；污染；人體健康風(fēng)險(xiǎn)評(píng)價(jià)
（1. School of Metallurgy and Environment, Central South University, Changsha 410083, China;
2. Beijing Research Institute of Uranium Geology, Beijing 100029, China;
3. Xuzhou Institute of Environmental Protection Science, Xuzhou 221006, China）
Abstract:In order to find out the pollution of heavy metals in surface soil around Dongting Lake wetland and its risk to human health, 10 soil sampling sites around Dongting Lake area were selected in this study from 2016 to 2018. 100 surface soil samples (0-30 m) were collected. The content and distribution of heavy metals were analyzed, and the methods of geo-accumulation index (Igeo), nemerow index (NI) and soil health risk assessment were used for risk assessment. The results show that the average concentrations of Pb, Cd, Hg, As and Cu in soil samples are 53.33, 1.62, 0.27, 26.8 and 37.72 mg/kg, respectively, which are higher than the background values of soil environment in the study area. Among them, the average concentrations of Cd and As, the concentrations of Cd in West Dongting Lake, South Dongting Lake and East Dongting Lake and the concentrations of As in South Dongting Lake are all higher than the criteria for screening the risk of agricultural land soil pollution in “Soil Environmental Quality Standard” (GB 15618—2018). The maximum pollution values of Cd, Hg, As and Cu are in South Dongting Lake, while the maximum pollution values of Pb are in East Dongting Lake. The study of geo-accumulation index (Igeo) show that Cd is at the level of serious pollution, and Pb, Hg and As are at the level of non-pollution to moderate pollution in three years. The nemerow index (NI) study shows that, in three years, West Dongting Lake, South Dongting Lake and East Dongting Lake are at slight pollution level. The assessment of human health risks using the three exposure factors of unintentional smoking, skin contact and breath contact in the soil health risk assessment system shows that the average of 13 adults and 8 children per million population are at risk of cancer. The results provide reference and suggestions for the sources and characteristics of soil pollution in Dongting Lake wetland.
Key words: Dongting Lake; soil; heavy metal; pollution; human health risk assessment
