| Mercury, a heavy metal pollutant, is toxic to human beings and animals. Any formof mercury in the environment can be transformed into methylmercury under certainconditions, which has much higher toxicity. The intake of mercury can take placethrough skin, breathing and mouth, jeopardizing human’s health. Since the MinamataDisease broke out in Japan in the1950s, mercury pollution has aroused great attention.In recent years, the mercury concentration in the global environment increases with time,which is caused by such human activities as metal smelting, combustion of fuel, mining,and so forth. Mercury is regarded as “a global pollutant” due to its long-distance,even transnational, transmission. Mercury could migrate and transform in the system ofsoil, water, atmosphere and human body. Soil and sediment are not only the importantgathering place of mercury, but also a main carrier for mercury entering into otherenvironmental media. Hair is able to directly reflect the levels of mercury content inhuman body. Hence, it is significant to study the mercury pollution in soils, sedimentsand hairs.This paper is aimed at studying the mercury pollution status and its potential risksin Xikou mercury mining area. Accordingly,10surface soil samples,7surface sedimentsamples, and14hair samples have been collected in the research area in March16,17,2013. Moreover, the content of total mercury has been analyzed, and environmentalrisks of mercury have also been evaluated. Preliminary conclusions of this research areas follows:(1) The total mercury concentrations of surface soil samples in the research arearanged from2.04to63.41mg/kg, with the average value26.653mg/kg. The totalmercury was significantly correlated with organic matter and cation exchange capacity，while has no obvious correlation with pH values. The analysis of mercury pollutiondegree in soil samples showed that1~9#samples were subjected to severe mercurypollution, while the10#sample was the exception because it was the background soil.The potential ecological risk assessment study results showed that1~9#samples hadextremely strong ecological hazards, while the10#sample had weak ecological hazards.(2) Health risk assessment of soil samples indicated that the average value of totalnon-carcinogenic hazard of mercury for adult through all exposure routes were4.01E-01and3.79E-01, respectively, when the land was utilized as either industrial land or residential land. Both average values were less than1, indicating that the noncarcinogenic risk of mercury on adults are acceptable whether the study area wasreclaimed as industrial land or residential land. When the study area was reclaimed asresidential land, the average value of total non-carcinogenic hazard of mercury onchildren through all exposure routes was2.25E+00(greater than1), indicating that thenon carcinogenic risk were unacceptable. This would have adverse effects on children’shealth, and the contribution rate of exposure ways followed by oral intake> skinintake> breathing intake.(3) The total mercury concentration of sediment in the research area ranged from3.66to87.36mg/kg, with the average value39.97mg/kg. The total mercuryconcentration in sediment samples had no obvious correlation with pH values. Theevaluation of total mercury pollution degree showed that all sediment samples had veryserious mercury pollution. Still, the potential ecological risk assessment results showedthat sediment samples had extremely strong ecological damage.(4) The mercury contents of hair collected in the research area was in the range of0.03~0.78mg/kg, with the average value0.19mg/kg. The mercury level of hair andhealth risk assessment of residents in the research area showed that people, donated hairsamples, did not suffer mercury contamination, and have no potential risk of mercuryexposure, which is probably due to less hair samples, the sampled locations and itsrandomness. |
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