某非规范垃圾填埋场地下水中污染物的健康风险评价

Health Risk Assessment for Ground Water Pollution Caused by a Substandard Landfill Site

目的评价华北某非规范垃圾填埋场地下水中污染物的健康风险。方法于2007年5月,采集华北某市附近一非规范垃圾填埋场附近5口有代表性的民用水井(即采样点1～5)水样,按照GB/T 5750—2006《生活饮用水标准检验方法》测定样品中的氨氮、硝酸盐氮、亚硝酸盐氮、挥发酚、锌、六价铬、汞、锰、pH值、氟化物、总硬度指标,并进行健康风险评价。结果仅采样点2的水样中检出化学致癌性污染物(六价铬),其由饮水途径所导致健康危害的个人年风险为7.60×10-4/a。水样中非致癌污染物饮水途径健康危害的风险平均为16.060×10-9/a。不同采样点各种非致癌性污染物由饮水途径所致健康危害的个人年风险比较,由高至低依次为:采样点2(24.861×10-9/a)>采样点4(17.753×10-9/a)>采样点3(17.701×10-9/a)>采样点5(11.718×10-9/a)>采样点1(8.265×10-9/a)。各种非致癌性污染物由饮水途径所致健康危害的个人年风险比较,由高至低依次为:汞(5.694×10-9/a)>硝酸盐氮(5.178×10-9/a)>氟化物(3.186×10-9/a)>挥发酚(0.869×10-9/a)>锰(0.532×10-9/a)>氨氮(0.344×10-9/a)>锌(0.250×10-9/a)>亚硝酸盐氮(0.006×10-9/a)。结论采样点2地下水受致癌性污染物和非致癌性污染物污染比较严重,不宜作为饮用水源。

Objective To assess the health risk of the ground water pollution caused by a substandard landfill site in northern China. Methods In May 2007, the water samples were collected from five representative civil wells situated near a substandard landfill site nearby a city in northern China. Ammonia nitrogen, nitrate nitrogen, nitrite nitrogen, volatile phenol, zinc, sexavalent chrome, mercury, manganese, pH values, fluoride, total hardness of the samples were determined according to the standard determination methods of domestic drinking water GB/T 5750-2006. The assessment of health risk was carried out. Results Only in the water samples collected from the sampling site 2, the carcinogenic toxicant （sexavalent chrome） could be detected. The health annual risk caused by sexavalent chrome via drinking water was 7.60×10^-4/a. The average value of health annual risk caused by noncarcinogenic toxicants was 16.060 ×10^-9/a. The values of health annual risk via drinking water caused by noncarcinogenic toxicants in water samples obtained from different water sampling sites were compared and arranged in descending order, sampling site 2 （24.861×10^-9/a）〉 sampling site 4 （17.753×10^-9/a）〉 sampling site 3 （17.701×10^-9/a）〉 sampling site 5 （11.718×10^-9/a）〉sampling site 1 （8.265×10^-9/a）. The values of health annual risk via drinking water caused by different non-carcinogenic toxicants arranged in descending order, mercury （5.694×10^-9/a）〉 nitrate nitrogen （5.178×10^-9/a）〉 fluoride （3.186×10^-9/a）〉 volatile phenol （0.869×10^-9/a）〉 manganese （0.532×10^-9/a）〉 ammonia nitrogen （0.344×10^-9/a）〉 zinc （0.250×10^-9/a）〉 nitrite nitrogen（0.006×10^-9/a）. Conclusion The carcinogenic toxicant pollution in water collected from sampling site 2 is serious, so it is can not be used as the drinking water source.