Mercury contamination and health risk to crops around the zinc smelting plant in Huludao City, northeastern China.
ABSTRACT The Huludao zinc plant in Liaoning province, northeast China was the largest in Asia, and its smelting activities had seriously contaminated soil, water and atmosphere in the surrounding area. For the first time, we investigated the total mercury (THg) content in maize, soybean, broomcorn, 22 vegetables, and the soil around their roots from eight sampling plots near the Huludao zinc plant. THg contents of the seeds of maize, soybean, and broomcorn are 0.008, 0.006, and 0.057 mg kg(-1), respectively, with the broomcorn being the highest, exceeding the maximum level of contaminant in food (GB2762-2005) by 4.7 times. The edible parts of vegetables are also contaminated with a range of mercury contents of 0.001-0.147 mg kg(-1) (dry weight). THg contents in plant tissue decrease in the order of leaves > root > stalk > grain. Using correlation analysis, we show that mercury in the roots of these plants is mainly derived from soil, and the uptake of gaseous mercury is the predominant path by which the mercury accumulated in the foliage. The average and maximum mercury daily intake (DI) of adult around the Huludao zinc plant via consuming vegetables are 0.015 and 0.051 microg/kg/d, respectively, and those of children are 0.02 and 0.07 microg/kg/d, respectively. The average and maximum weekly intakes of total mercury for adult are 2.1 and 7.1%, respectively, of the provisional tolerable weekly intake (PTWI), and 2.8 and 9.7%, respectively, of the PTWI for children.
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ABSTRACT: A field survey of mercury pollution in environmental media and human hair samples obtained from residents living in the area surrounding the Chatian mercury mine (CMM) of southwestern China was conducted to evaluate the health risks of mercury to local residents. The results showed that mine waste, and tailings in particular, contained high levels of mercury and that the maximum mercury concentration was 88.50 μg g(-1). Elevated mercury levels were also found in local surface water, paddy soil, and paddy grain, which may cause severe health problems. The mercury concentration of hair samples from the inhabitants of the CMM exceeded 1.0 μg g(-1), which is the limit recommended by the US EPA. Mercury concentrations in paddy soil were positively correlated with mercury concentrations in paddy roots, stalks, and paddy grains, which suggested that paddy soil was the major source of mercury in paddy plant tissue. The average daily dose (ADD) of mercury for local adults and preschool children via oral exposure reached 0.241 and 0.624 μg kg(-1) body weight per day, respectively, which is approaching or exceeds the provisional tolerable daily intake. Among the three oral exposure routes, the greatest contributor to the ADD of mercury was the ingestion of rice grain. Open-stacked mine tailings have resulted in heavy mercury contamination in the surrounding soil, and the depth of appreciable soil mercury concentrations exceeded 100 cm.Environmental Geochemistry and Health 06/2012; · 2.08 Impact Factor
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ABSTRACT: The aim of this study was to investigate arsenic (As) accumulation in street dust and health risk of population. The investigation concentrated on: a. pollution levels of As in street dust; b. spatial distribution of As in street dust; c. physicochemical properties analysis of street dust; and d. assessment of population health risk due to As exposure to street dust. As concentration in street dust ranged from 3.33 to 185.1 mg kg(-1), with a mean of 33.10 mg kg(-1), which was higher than the background value of Liaoning soil. As contamination level of the area closing to Huludao Zinc Plant (HZP) was highest. Spatial variation showed that the pollution center was close to HZP, formed radial distribution pattern and extended to the northeast and southwest of HZP. The pH and organic matter of street dust were both higher than the background values of soil in Liaoning. There was significantly negative correlation between As concentration and the pH. The mass percentages of particles 180-100, <100-75, <75-63, and <63 μm were 29.8, 3.7, 21.3, and 4.2 %, respectively. The highest of As concentration was found in the smallest particle size (<63 μm). As loadings in the particles of grain size 180-100 and <75-63 μm were higher than other particle fractions. Results of the risk assessment indicated that the highest risk was associated with the ingestion of street dust particles. Health risk for different use scenarios to human decreased in the order of HZP > Industrial district > School > Commercial center > Residential area. Around HZP, Hazard Index (HI) for children and cancer risk of As by street dust exposure exceeded the acceptable values. It indicated that there was a potential adverse effect on children health by As exposure to the street dust of Huludao.Environmental Geochemistry and Health 06/2012; · 2.08 Impact Factor
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ABSTRACT: Cadmium (Cd) and zinc (Zn) in surface water, sediment, carp, and crab samples collected from upstream and downstream regions of the coastal watersheds along the Chinese Northern Bohai and Yellow Seas were analyzed to provide a comprehensive understanding and assessment of their environmental concentrations and bioaccumulations. The results showed that downstream waters contaminated with Zn would have adverse effects on aquatic organisms. Although nearly all sediments were contaminated with Cd due to human activities, little potential existed for Cd toxicity in sediment-dwelling fauna. The concentrations of Cd and Zn in most water, sediment, carp, and crab samples were below published values. The downstream carp and crabs had higher mean bioaccumulation factors and biota-sediment accumulation factors for Cd but lower mean biota-sediment accumulation factors for Zn than the upstream carp and crabs. Based on the relationships among the Cd and Zn concentrations in water, sediment, and biota, the authors can conclude that the Cd and Zn in crabs primarily derived from sediment exposure. Although Cd and Zn in the water and sediment originated from some of the same sources, the sources of Cd or Zn in water were likely different from those in sediment. Environ. Toxicol. Chem. © 2013 SETAC.Environmental Toxicology and Chemistry 01/2013; · 2.62 Impact Factor