School of Civil Engineering and the Environment, University of Southampton, Highfield, Southampton SO17 1BJ, UK.
Sci Total Environ. 2011 May 1;409(11):2272-80. doi: 10.1016/j.scitotenv.2009.12.040. Epub 2010 Jan 21.
Mercury (Hg) is released either naturally in the environment or by anthropogenic activities. During its global circulation, Hg presents in a diversity of chemical forms and transforms between each other. Among Hg species, methylmercury (MeHg) is readily absorbed by humans via the aquatic food chain and thus it is very neurotoxic to exposed populations including fetuses due to perinatal exposure. In 2005, a survey was carried out in Temirtau, an Hg-contaminated site in North Central Kazakhstan, to investigate Hg concentrations in the hair samples of the residents and the relationship between Hg exposure levels and the related factors. Among the 289 hair samples, Hg concentrations ranged from 0.009 to 5.184µg/g with a mean of 0.577µg/g. Nearly 17% of the population exceeded 1µg/g for hair Hg, which corresponds to the reference of dose (RfD) 0.1µg/kg body weight/day developed by the United States Environmental Protection Agency (USEPA). Subgroups of males, people aged over 45 and fishermen or anglers were found to have elevated Hg exposure levels in their hair. A positive correlation was found between Hg concentrations in hair and frequencies of river fish consumption. As a result, the finding that people were exposed to high levels of Hg was expected due to the frequent consumption of fish caught from the polluted River Nura or the neighbouring lakes. A regression model showed that approximately 41% of variance of Hg concentrations in the study population's hair was attributed to the variables of gender, residential location, age and fishery occupation. The model implied that demographic characteristics together with dietary behaviour should be taken into account in studies associated with Hg exposure risk, in order to clearly define the group potentially sensitive to Hg exposure.
汞(Hg)在环境中要么自然释放,要么由人为活动释放。在其全球循环过程中,汞以多种化学形态存在,并在彼此之间转化。在汞的各种形态中,甲基汞(MeHg)很容易通过水生食物链被人类吸收,因此对包括胎儿在内的暴露人群具有很强的神经毒性,因为其在围产期会暴露于甲基汞。2005 年,在哈萨克斯坦中北部受汞污染的铁米尔套(Temirtau)进行了一项调查,以调查居民头发样本中的汞浓度以及暴露水平与相关因素之间的关系。在 289 个头发样本中,汞浓度范围从 0.009 到 5.184µg/g,平均值为 0.577µg/g。将近 17%的人群头发中的汞含量超过 1µg/g,这对应于美国环境保护署(USEPA)制定的参考剂量(RfD)0.1µg/kg 体重/天。研究发现,男性、45 岁以上人群和渔民或垂钓者的头发中的汞暴露水平较高。头发中的汞浓度与河流鱼类食用频率呈正相关。因此,由于经常食用从受污染的 Nura 河或附近湖泊捕获的鱼类,人们接触到高浓度汞的可能性很大。回归模型显示,研究人群头发中汞浓度的约 41%可归因于性别、居住地点、年龄和渔业职业等变量。该模型表明,在与汞暴露风险相关的研究中,人口统计学特征和饮食行为应被纳入考虑,以便明确界定可能对汞暴露敏感的群体。