Cadmium, lead, and arsenic contamination in paddy soils of a mining area and their exposure effects on human HEPG2 and keratinocyte cell-lines.
A mining district in south China shows significant metal(loid) contamination in paddy fields. In the soils, average Pb, Cd and As concentrations were 460.1, 11.7 and 35.1mgkg-1respectively, which were higher than the environmental quality standard for agricultural soils in China (GB15618-1995) and UK Clea Soil Guideline Value. The average contents of Pb, Cd and As in rice were 5.24, 1.1 and 0.7mgkg-1respectively, which were about 25, 4.5 or 2.5 times greater than the limit values of the maximum safe contaminant concentration standard in food of China (GB 2762-2012), and about 25, 10 or 1 times greater than the limit values of FAO/WHO standard. The elevated contents of Pb, Cd and As detected in soils around the factories, indicated that their spatial distribution was influenced by anthropogenic activity, while greater concentrations of Cd in rice appeared in the northwest region of the factories, indicating that the spatial distribution of heavy metals was also affected by natural factors. As human exposure around mining districts is mainly through oral intake of food and dermal contact, the effects of these metals on the viability and MT protein of HepG2 and KERTr cells were investigated. The cell viability decreased with increasing metal concentrations. Co-exposure to heavy metals (Pb+Cd) increased the metals (Pb or Cd)-mediated MT protein induction in both human HepG2 and KERTr cells. Increased levels of MT protein will lead to greater risk of carcinogenic manifestations, and it is likely that chronic exposure to metals may increase the risk to human health. Nevertheless, when co-exposure to two or more metals occur (such as As+Pb), they may have an antagonistic effect thus reducing the toxic effects of each other.



Metal contaminations in paddy soils and rice were influenced by anthropogenic activity; metal co-exposure induced MT protein in human cells.
School of Metallurgy and Environment, Central South University, Changsha 410083, China.
Shengguo
S
Xue
School of Metallurgy and Environment, Central South University, Changsha 410083, China.
Lizheng
L
Shi
School of Metallurgy and Environment, Central South University, Changsha 410083, China. Electronic address: wuchuan@csu.edu.cn.
Chuan
C
Wu
School of Metallurgy and Environment, Central South University, Changsha 410083, China.
Hui
H
Wu
Shenzhen Polytechnic, Shenzhen 518055, China.
Yanyan
Y
Qin
College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha 410128, China.
Weisong
W
Pan
Crop and Environment Sciences Department, Harper Adams University, Newport, Shropshire, TF10 8NB, United Kingdom.
William
W
Hartley
School of Metallurgy and Environment, Central South University, Changsha 410083, China.
Mengqian
M
Cui
D001151:Arsenic / Q000032:analysis / Q000378:metabolism / Q000633:toxicity*; D002104:Cadmium / Q000032:analysis / Q000378:metabolism / Q000633:toxicity*; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D002681:China; D005786:Gene Expression Regulation / Q000187:drug effects; D056945:Hep G2 Cells; D006801:Humans; D015603:Keratinocytes / Q000166:cytology / Q000187:drug effects; D007854:Lead / Q000032:analysis / Q000378:metabolism / Q000633:toxicity*; D008668:Metallothionein / Q000235:genetics / Q000378:metabolism; D008906:Mining; D012275:Oryza / Q000737:chemistry* / Q000378:metabolism; D012989:Soil Pollutants / Q000032:analysis / Q000633:toxicity*
D012989:Soil Pollutants; D002104:Cadmium; D007854:Lead; D008668:Metallothionein; D001151:Arsenic
Arsenic; Cadmium; Cell exposure effects; Lead; Soil contamination