【作者】 钟莉莉；

【导师】 周永章；

【作者基本信息】 中山大学 ， 矿物学、岩石学、矿床学， 2007， 硕士

【摘要】 Pb是自然界常见的有毒重金属元素之一。系统剖析铅的区域分布特征、赋存规律,以及与地方流行病的关系具有重要的环境意义。本研究主要选择全国三大肝癌高发区之一的佛山市顺德区和南海区作为研究区,分析研究区土壤和饮用水体中Pb全量、有效量以及元素有效性及其主要影响因素,评价Pb的局部背景水平和异常程度,剖析Pb的异常特征,分析异常成因,分析地球化学环境与地方性疾病的相关性。本研究取得了以下主要结论和认识:(1)研究区Pb污染程度较轻,达到国家土壤环境标准的二级标准。表层土与深层土的全Pb含量没有显著的相关关系。大多数采样点表层和深层土壤全Pb含量与pH值有较明显的相关关系。(2)选取肝癌高发区杨滘村和相对低发区大闸村的土壤纵向剖面进行对比分析显示,在0～40cm,两条剖面的土壤全Pb含量均有明显波动,波动程度随着深度加深而降低;在40cm深度以下,土壤全Pb含量接近土壤环境质量标准的自然背景值,随深度下降变化不明显。同一深度进行比较发现,大闸剖面9个层位的土壤全Pb含量均稍大于杨滘剖面的土壤全Pb含量。(3)与南海区域背景值相比,研究区的农业土壤全Pb含量均值比南海区背景值低27.6 mg/kg,约为南海区背景值的63.67%。顺德区乐从镇的农业土壤全Pb含量与南海区的基塘地区、北部的狮山、南部的丹灶的农业土壤全Pb含量相当。(4)应用土壤重金属污染的地累积系数法和单因子污染指数评价方法评价指示:研究区内表层土壤的污染程度较轻,在空间分布上未见明显规律。以国家土壤环境质量自然背景值和广东省土壤背景值为基准,研究区内大部分的表层土样基本无污染,小部分为低至中度污染。(5)采用七步萃取法进行Pb形态提取分析指示:有效态(水溶态、可交换态、碳酸盐结合态之和)含量最高的是19(大闸)、18(水藤)号点,均大于6 mg/kg。其次9、11、17、16、3号点,有效态含量在3.0～5.1 mg/kg之间。2(杨滘）、13(水藤)、7(罗沙)号点的有效态含量最少,小于1 mg/kg。(6)研究区域内,Pb有效态的空间分布较均匀。最高值出现在研究区东部和东南部(大闸村),最低值出现在研究区的西北部罗沙村附近和北围工业区附近。肝癌高发区的杨滘、罗沙、水藤村Pb有效态的分布无明显规律。与肝癌低发区大闸村对比,两区的Pb有效态最高值和最低值非常接近。(7)潜在可利用态(腐殖酸结合态、铁锰氧化结合态、强有机结合态之和)含量最高的是6(罗沙)号点,为40.03mg/kg,其次是4(杨滘）、13(水藤)号点,在30～40mg/kg范围,8(罗沙)号点最低,15.45 mg/kg,其余点的潜在可利用态含量在15～30 mg/kg之间。潜在可利用态与全铅的相关性非常好。(8)与1987年的前人对顺德肝癌高发区和低发区的地球化学调查结果对比,本研究区肝癌高发区表层农业土壤和井水中的全Pb含量均值偏低,但全Pb含量取值范围都在1987年所测值范围内。本次研究结果也符合全Pb含量与肝癌发病率呈负相关关系的规律。本研究区的铅地球化学特征与地方流行病肝癌的成因无显著关系。更多还原

【Abstract】 Lead is one of natural poisonous heavy metal elements. It has important environmental meanings to study systematically characteristics of existing、distributing of lead and the relation between lead and regional epidemic.This research chose one of the three areas which had frequent liver cancers in the whole country——the Shunde and Nanhai in Foshan City as the research object. Then analysis total quantity of the lead in soil and drinking water, valid quantity and chemical element usefulness and its main impact factors. And evaluated background level of lead and excrescent degree in the area, analysis excrescent characteristics of lead and abnormality reason. Finally we find out the relationship between geochemistry environment and regional epidemic in the area.It is concluded that:(1) Lead contamination’s degree was light in the study area. It attained second class of the National Soil Environment Standard. The total quantity content of lead in the surface layer of soil didn’t related significantly to it in the deep soil. Total lead contents of most soil samples related significantly to pH value both surface layer and deep layer.(2) Compared Yangjiao village which is known as higher frequent liver cancer with Dazha village which has lower frequent liver cancer. The lead’s total quantities of two soil sections have both obvious difference lengthways from 0 to 40 centimeters, they descend along with the depth adds. The total quantities of the lead in soil sections near the natural background value of the quality standard of the soil environment, and they don’t change obviously along with the depth adds from 40 centimeters depth to the bottom. The lead’s total quantities in 9 layers of the Dazha section are slightly higher at the same depth than them in the Yangjiao soil section.(3) Compared with the soil background value in the Nanhai district, the total lead average content of the agriculture soil in the research area is lower 27.6 mgs/kg than it in the Nanhai area, and the number is about 63.67% of Nanhai area. The total lead average content of agriculture soil in the Lecong town is close to it in the Jitang region of the Nanhai district, of the Shishan area in northeast Nanhai district and of the agriculture soil at south Danzao area in northeast Nanhai district.(4) The conclusions are as the following if the ground enrichment factors method and single factor index method are used: the pollution degree is light in the research area, and the distributing rule of pollution is not obvious. With the national natural background value of the soil and soil background in Guangdong province, a majority of surface layer soil was free from pollution, and small part had low to medium pollution in the study area.(5) The conclusions are as the following by adopting 7 extracts method: the highest metal availability (containing the water dissolve form, the exchangeability form, and the carbonate to combine form) is in the 19th point (in Dazha village) and in the 18th point (in Shuiteng village), they were more than 6 mg/kg. Secondly, in 9th, 11th, 17th, 16th and 3rd points, the availabilities were between 3.0 to 5.1 mg/kg. And the availabilities of 2nd (in Yangjiao village), 13th (in Shuiteng village) and 7th (in Luosha village) minimal, lower than 1 mg/kg.(6) The geography position of the lead valid form distributes were even inside the study district. The highest value appeared in the east and the southeast (in Dazha village); the lowest value appeared in the northwest hereabout Luosha village and Beiwei industrial area. In the frequent liver cancer area——Yangjiao, Luosha and Shuiteng village, the lead valid form distributed to have no obvious regulation. Contrast with Dazha village, the lead valid form value of the 2 areas was very close between the highest one and the lowest one.(7) Latent useful form contained the humic acid combine form, iron manganese to oxidize to combine form and strong organic combine form. The highest latent useful form is the 6th point (in Luosha village), for 40.03 mgs/kg is in the 4th point (in Yangjiao village) and the 13th point (in Shuiteng village). Secondly, at 30 to 40 mgs/kg scope. The 8th point (in Luosha village) was lowest, only 15.45 mgs/kg. The rest points of latent useful form were between 15 to 30 mgs/kg. Latent useful form with the relativity of total lead value very good.(8) Compared to the former study result of the geochemistry research in Shunde higher and lower frequent liver cancer area in 1987, the total quantity of the lead were on the low side in the surface layer agriculture soil and well. And the value range was inside of the former result. But the value scopes were the result scope gained by past study. The result we gained accord with the rule that the total quantity of the lead are minus the incidence of liver cancer. The cause of liver cancer formation without specially related relation by lead geochemistry characteristic in the Shunde area.更多还原