title: Potential health risk in areas with high naturally-occurring cadmium background in southwestern China.
abstract: In various parts of the world, high cadmium (Cd) concentrations in environment are not related to anthropogenic contamination but have natural origins. Less is known about health risks that arise under these conditions. This study aimed to discuss the pollution of Cd with natural sources, and to investigate the concentration of Cd in food crops and the urine of inhabitants in an area of southwestern China. The results showed that the arable soils are moderately contaminated by Cd (I(geo)=1.51) relative to the local background, with a high ecological risk (Er=218). The chemical fractions of Cd in soils with natural sources are probably controlled by parent materials and mostly in residual phase. The average Cd concentrations were 0.68 mg kg(-1) (fresh weight) in local vegetables, 0.04 mg kg(-1) in rice, and 0.14 μg L(-1) in water. Leafy vegetable tends to accumulate more Cd than the other crops. The calculated Target Hazard Quotient (THQ) had a much higher value (4.33) for Cd, suggesting that Cd represents a significant potential risk to the local population. The urinary Cd concentrations (mean at 3.92 μg L(-1) for male and 4.85 μg L(-1) for female) of inhabitants in the study area were significantly higher (p<0.05) than those from the control area (mean at 0.8 μg L(-1) for male and 0.42 μg L(-1) for female). Male and female test subjects had similar urinary Cd levels (p>0.05), but age seemed to lead to an increase in Cd in the urine. These findings show that naturally-occurring Cd in local soils is taken up appreciably by local food crops, and that dietary exposure of Cd through vegetable ingestion is a major exposure pathway for local populations, and a potential risk to public health in the study area.
authors.affiliation: State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China; University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Yizhang
authors.initials: Y
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China. Electronic address: xiaotangfu@vip.gyig.ac.cn.
authors.forename: Tangfu
authors.initials: T
authors.lastname: Xiao
authors.affiliation: Soil and Water Laboratory, Department of Civil and Environmental Engineering, Rensselaer Polytechnic Institute, Troy, NY 12180, USA.
authors.forename: Philippe C
authors.initials: PC
authors.lastname: Baveye
authors.affiliation: State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China.
authors.forename: Jianming
authors.initials: J
authors.lastname: Zhu
authors.affiliation: State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China.
authors.forename: Zengping
authors.initials: Z
authors.lastname: Ning
authors.affiliation: Health Bureau of Wushan County, Chongqing 404700, China.
authors.forename: Huajun
authors.initials: H
authors.lastname: Li
mesh_terms: D000328:Adult; D002104:Cadmium / Q000378:metabolism / Q000633:toxicity* / Q000652:urine; D002681:China; D002523:Edible Grain / Q000378:metabolism; D004784:Environmental Monitoring; D005260:Female; D005506:Food Contamination / Q000032:analysis*; D006801:Humans; D008297:Male; D013058:Mass Spectrometry; D008875:Middle Aged; D018570:Risk Assessment; D012989:Soil Pollutants / Q000378:metabolism / Q000633:toxicity* / Q000652:urine; D014675:Vegetables / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000378:metabolism / Q000633:toxicity* / Q000652:urine; D055815:Young Adult
chemical_list: D012989:Soil Pollutants; D014874:Water Pollutants, Chemical; D002104:Cadmium
keywords: Cadmium; Dietary exposure; Food crops; Health risk; Pollution