广西环境镉污染重点地区居民饮用水、食物和空气镉暴露量调查

Levels of cadmium exposure via drinking water,food and air in residents living in environmental cadmium-contaminated areas in Guangxi

目的了解广西镉污染区饮用水、食用农产品和空气镉污染状况,对居民通过饮用水、食物和空气镉暴露水平进行评估。方法 2014-2015年在广西污染区和对照区分别采集饮用水、食物和空气样品,采用电感耦合等离子体质谱测定法(ICP-MS)检测重金属镉指标,应用点评估方法计算居民环境镉暴露量,评价暴露风险。结果污染区和对照区饮用水镉含量中位数分别为0.000 25和0.000 05 mg/L,合格率均为100.0%,污染区饮用水镉含量高于对照区,差异有统计学意义(P<0.05)。污染区空气镉含量中位数为12.4 ng/m3,高于对照区的2.69 ng/m3,差异有统计学意义(P<0.05);污染区食物中的大米、干豆类和蔬菜类镉含量中位数分别为0.389、0.216、0.052 mg/kg,均高于对照区(分别为0.119、0.161、0.025 mg/kg)。污染区和对照区调查对象每人每日从环境介质(饮水、食物和空气)摄入镉的暴露量分别为117. 46、39.55μg,其中食物镉摄入分别为116. 77和39.41μg,占比99%以上;每月膳食镉摄入量分别为61. 78、20.85μg/(kg·BW),每月通过膳食摄入镉的量分别是PTMI的2.47、0.83倍。结论广西污染区食物镉暴露对人群健康存在潜在影响。

Objective To investigate the status of cadmium pollution in drinking water,edible agricultural products and air in the cadmium-contaminated areas of Guangxi,and to assess the levels of cadmium exposure via drinking water,food and air in the residents. Methods Drinking water,food and air samples were collected in both contaminated and control areas in Guangxi in2014-2015. The concentration of heavy metal cadmium was detected by inductively coupled plasma mass spectrometry（ ICP-MS）,and the point estimate model was used to calculate the cadmium exposure levels in residents and evaluate the exposure risk. Results The medians of cadmium content in drinking water in the contaminated and control areas were 0. 000,25 mg/L and0.000,05 mg/L respectively,with the qualified rates being both 100%. The cadmium content in drinking water were higher in the contaminated areas than in the control areas,with a statistically significant difference（ P〈0.05）. So were the medians of cadmium contents in air（ 12.4 ng/m3 vs. 2.69 ng/m3）,rice（ 0.389 mg/kg vs. 0.119 mg/kg）,dried beans（ 0.216 mg/kg vs. 0.161 mg/kg）and vegetables（ 0.052 mg/kg vs. 0.025 mg/kg）. The daily per capita cadmium exposure through environmental media（ including drinking water,food and air） in participants from the contaminated and control areas were 117.46 μg and 39.55 μg respectively,of which the cadmium intakes from food were 116.77 μg and 39.41 μg respectively,accounting for 99% of the total. The monthly dietary cadmium intakes in the contaminated and control areas were 61.78 μg/（ kg·BW） and 20.85 μg/（ kg·BW） respectively,being 2.47 times and 0.83 times of provisional tolerated monthly intake（ PTMI） of cadmium. Conclusion Dietary cadmium exposure in cadmium-contaminated areas in Guangxi is a potential health risk.