【作者】 罗锦洪；

【导师】 郑丙辉； 黄民生；

【作者基本信息】 华东师范大学 ， 环境工程， 2012， 博士

【摘要】 饮用水源地的水华事件已成为威胁饮用水源安全和暴露人体健康的环境污染问题。合理地评价水华具有的人体健康风险,是开展饮用水源地水华应急管理的基础。开展饮用水源地水华健康风险评价,需要以保护人体健康为目的,以水华水体急性暴露的健康风险大小为研究对象,采用污染物健康风险评价模型,评价水华污染水体具有的人体健康风险大小饮用水源地水华的危害识别结果表明,饮用水源地受水华污染时,水体中主要污染物为MCs和DBPs。MCs作为一类肝毒素,主要作用于人体的肝细胞和肝巨噬细胞,最终导致人体患肝病。DBPs主要表现为致癌性和生殖毒性。采用水体中污染物急性暴露安全阈值(浓度)的计算方法,确定了MCs和DBPs的急性暴露安全阈值(浓度)。MC-LR、三氯甲烷、一溴二氯甲烷、三溴甲烷、二氯乙酸、三氯乙酸经饮用水暴露的急性暴露安全(阈值)浓度,分别为0.004、18、0.25、0.2、2、0.13、0.5mg/L。氯化过程中MC-LR和DBPs污染特征的结果表明,原水氯化后水体中MC-LR浓度范围为0.11-3.89μg/L。不同水质指标与氯化后水体巾MC-LR的线性相关性结果表明：MC-LR浓度与水体Chl-a、TP和NH3-N呈线性正相关,线性相关系数分别为0.85、0.75和0.81。MC-LR浓度与N/P成线性负相关性,R2=0.73。原水中不同有机质组分的树脂分离结果表明：原水中溶解性有机质以疏水酸性物质为主。氯化后水体检出的主要DBPs为：三氯甲烷、一溴二氯甲烷、二溴一氯甲烷、三溴甲烷、一氯乙酸、二氯乙酸和三氯乙酸,其生成量的范围分别为：1.85-52.5、1.31-183、1.32-194、0.19-15.8、0.22-118、0.15-85.3和1.05-28.4μg/L。原水水质指标与DBPs生成量之间的线性相关性表明：HAAs与水体Chl-a浓度相关性最高(R2=0.75),与DOC浓度、NH3-N及1n(藻密度)的相关性次之,与TN和TP的相关性较差。THMs的生成量与水体中DOC浓度相关性最高(R2=0.87),与水体N/P的相关性最差(R2=0.27)。按照污染物暴露量计算模型,确定了不同人群的日均暴露量。当水体Chl-a浓度范围为21.40-195.6μg/L时,成人对MC-LR、THMs、HAAs的日均暴露剂量分别为：3.14×10-6～1.11×10-4、2.04×10-4～1.17×10-2、7.94×10-5～3.81×10-3μg/kg·day;儿童对MC-LR、THMs、HAAs的日均暴露剂量分别为：1.10×10-5～3.89×10-4、7.15×10-4～4.44×10-2、2.78×10-4～1.33×10-2μg/kg·day。采用污染物急性健康风险表征方法,表征了不同水华污染水体的健康风险,结果表明：当水体中Chl-a浓度范围属于21.4-195.6μg/L时,水华非致癌风险值随Chl-a浓度的增加,呈逐渐上升的趋势,健康风险值介于0.17-4.39之间。水华致癌风险级别介于1.26×10-5-9.25×10-4/a之间。界定了3个不同的水华健康风险级别,当水体中Chl-a浓度低于80μg/L时,为无风险级；介于80-120μg/L时,为低风险级；高于120μg/L时,为高风险级。饮用水源地水华健康风险评价不仅采用健康风险评价的手段,指导饮用水源地管理的一个新尝试,也是污染物急性人体健康风险评价的初步探索,具有一定的理论创新性和应用价值。更多还原

【Abstract】 Algal blooms occurred in drinking water source is a threat to drinking water source safety and human health in China. It is the precondition of algae bloom emergency management to assess the human health risk reasonably. In order to protect human health, the risk of acute exposure to algae bloom water was evaluated by health risk assessment chemical model.The human health hazard chemicals are mainly Microcystins (MCs) and Disinfection By-Products (DBPs) in algae bloom polluted water. MCs are one kind of hepatic toxin, act on liver cells and liver macrophages, leading to human liver disease. The health hazards of DBPs are carcinogenicity and reproductive toxicity. Based on the method of acute exposure safety threshold, the acute safety thresholds of MCs and DBPs were calculated. The safety threshold of MC-LR, chloroform, Bromodichloromethane, bromoform, dichloroacetic acid, trichloroacetic acid are0.004,18,0.25,0.2,2,0.13,0.5mg/L, respectively.The pollution characteristics of MCs and DBPs in chlorination were investigated. The MC-LR concentration is0.11-3.89μg/L in chloride water. Linear correlation analysis of water quality index and MC-LR concentration were conducted. The correlation of MC-LR and Chl-a, TP, NH3-N are positive, R2are0.85,0.81and0.75, respectively. The correlation of MC-LR with N/P is negative correlation. By the Resin adsorption method, the DOM fractions were characterized. The results show that HIS is the mainly fraction in raw water. chloroform, bromodichloromethane, dibromochlomethane, bromoform chloroactic acid, dichloroacetic acid and trichloroacetic acid are detected in chloride water. Other DBPs species are observed some time. The vary concentration range of chloroform, bromodichloromethane, dibromochlomethane, bromoform, chloroactic acid, dichloroacetic acid and trichloroacetic acid are:1.85～52.5,1.31～183.25,1.32～194.35,0.19～15.83,0.22～118.6,0.15-85.3and1.05～28.46μg/L, respectively. The correlation analysis between water quality index and DBPs yields shows that HAAs is highly correlated with the concentration of Chl-a (R2=0.75), but the linear correlation with TN and TP correlation is lower. THMs is correlated with the highest concentration of DOC (R2=0.87), and the correlation with N/P is the worst (R2=0.27).The average daily exposure dosage of different chemical was calculated. As the Chl-a concentration in the range of21.4～195.6μg/L, the average daily dosage of adult to MC-LR, THMs, HAAs were3.14×10-6～1.11×10-4、2.04×10～4-1.17×10-2、7.94×10-5-3.81×10-3μg/kg·day, respectively. The average daily dosage of children to MC-LR, THMs, HAAs were:1.10×10-5-3.89×104、7.15×10-4～4.44×10-22.78×10-4-1.33×10-2μg/kg·day. The health risk of algae bloom was characterized. As the Chl-a concentration is during21.4～195.6μg/L, with the increased of Chl-a concentration, the non-cancer risk is increased frequently, the health risk value is during0.17-4.39. The cancer risk of different algae polluted water is between1.26×10-5～9.25×10-4/a. The human health risk covers three different risk levels:no risk level, low risk level and high risk level. When Chl-a concentration is below80μg/L, the water belongs to no risk level. When it is between80～120μg/L, the water belongs to low risk level. When it is beyond120μg/L, the water belongs to high risk level.Algae bloom health risk assessment is only a new attempt by using health risk assessment method to guide drinking water source management but also a preliminary research in acute human risk assessment of chemical. This research has certain theoretical innovation and application value.更多还原