贵州省典型铅锌矿区和贵阳市居民汞暴露以及健康风险评估

Mercury exposure and health risk assessment in typical lead-zinc mining areas and Guiyang City.

选择贵州省赫章县铅锌矿区和贵阳市居民区,采集了居民日用食物(大米、土豆、鸡蛋、蔬菜、鱼肉、猪肉)、饮用水和农作物根际土壤,共计503个,测定了总汞和甲基汞的含量,并结合蒙特卡洛模拟评估了居民无机汞和甲基汞暴露风险。结果如下:(1)铅锌矿区的样品总汞和甲基汞的范围分别为0.11~39和0.028~1.7 ng·g^(-1),城市居民区的样品总汞和甲基汞的范围分别为0.07~18和0.01~7.7 ng·g^(-1),除蔬菜外的样品总汞含量低于我国食品限量标准,蔬菜总汞含量分别有14.7%(铅锌矿区)和17.7%(城市居民区)的样品超过我国《食品安全国家标准》(GB 2672—2017)规定的10 ng·g^(-1)。(2)两个地区无机汞日暴露量无差异(城市居民区:0.031μg·kg^(-1)·d-1,铅锌矿区:0.032μg·kg^(-1)·d-1),但城市居民区的甲基汞日暴露量(0.006μg·kg^(-1)·d-1)高出铅锌矿区(0.0032μg·kg^(-1)·d-1)近1倍。(3)两个地区居民无机汞和甲基汞的平均日暴露量分别低于联合国粮农组织/世界卫生组织食品添加剂联合专家委员会(JECFA)推荐的人体安全无机汞的临时容许每周摄入量(PTWI)4μg·kg^(-1)·week-1和美国环境保护署(USEPA)推荐的甲基汞参考剂量(RfD)0.1μg·kg^(-1)·d-1,暴露风险指数均小于1,表明处于健康安全水平。

To assess food contamination levels of organic(MeHg)and inorganic mercury associated with mining and urban environments in Guizhou,we analyzed 503 samples from Hezhang County(lead-zinc mining area)and Guiyang.The health risk associated with dietary consumption was assessed using Monte Carlo simulations.The highest levels of total mercury were 39 and 18 ng·g^(-1) in the samples from the mining area and the urban residential area,respectively.The corresponding highest measurement values for MeHg were 1.7 and 7.7 ng·g^(-1),respectively.The investigated foodstuffs such as rice,potatoes,chicken eggs,fish,pork did not contain significant levels of mercury contamination,with the exception of certain vegetables that frequently showed levels above the current limit standard of 10 ng·g^(-1).14.7%(lead/zinc mining area)and 17.7%(residential area)of vegetable samples exceeded the limit specified in China’s National Food Safety Standard(GB 2672-2017).Dietary inorganic mercury exposure was similar for food with different origins(residential area:0.031μg·kg^(-1)·d-1,lead-zinc mining area:0.032μg·kg^(-1)·d-1),while exposure to organic mercury was nearly twice greater in the urban environment(6.0 vs.3.2 ng·kg^(-1)·d-1).In general,the average daily exposure to inorganic mercury and MeHg was lower than the provisional weekly tolerable intake(PTWI)of 4μg·kg^(-1)·week-1 for IHg by WHO/JECFA and the reference dose(RfD)of 0.1μg·kg^(-1)·d-1 for MeHg established by USEPA,respectively.Hazard index in both regions was much less than unity,suggesting no obvious non-carcinogenic health risks.