title: Application of biochar to soil reduces cancer risk via rice consumption: a case study in Miaoqian village, Longyan, China.
abstract: Consumption of rice contaminated with potentially toxic elements (PTEs) is a major pathway for human exposure to PTEs. This is particularly true in China's so called "Cancer Villages". In this study, sewage sludge biochar (SSBC) was applied to soil (at 5% and 10%) to suppress PTE phytoavailability and as a consequence to reduce PTE levels in rice grown in mining impacted paddy soils. Risk assessment indicated that SSBC addition (10%) markedly (P≤0.05) decreased the daily intake, associated with the consumption of rice, of PTEs (As, Cd, Co, Cu, Mn, Pb and Zn by: 68, 42, 55, 29, 43, 38 and 22%, respectively). In treatments containing SSBC (10%) the health quotient (HQ) indices for PTEs (except for As, Cu and Mn) were <1, indicating that SSBC suppressed the health risk associated with PTEs in rice. The addition of SSBC (10%) markedly (P≤0.01) reduced AsIII (72%), dimethylarsinic acid (DMA) (74%) and AsV (62%) concentrations in rice. Consequentially, following SSBC application (10%), the incremental lifetime cancer (ILTR) value for iAs (AsIII+AsV) associated with the consumption of rice was significantly (P≤0.01) reduced by 66%. These findings suggest that SSBC could be a useful soil amendment to mitigating PTE exposure, through rice consumption, in China's "Cancer Villages".
authors.affiliation: Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; Department of Environmental Science, University of Peshawar, Peshawar, Pakistan.
authors.forename: Sardar
authors.initials: S
authors.lastname: Khan
authors.affiliation: School of Environmental Sciences, University of East Anglia, Norwich, UK.
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Reid
authors.affiliation: Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China.
authors.forename: Gang
authors.initials: G
authors.lastname: Li
authors.affiliation: Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China. Electronic address: ygzhu@rcees.ac.cn.
authors.forename: Yong-Guan
authors.initials: YG
authors.lastname: Zhu
mesh_terms: D018533:Biomass; D002606:Charcoal / Q000737:chemistry*; D002681:China; D004032:Diet; D004781:Environmental Exposure; D005506:Food Contamination / Q000517:prevention & control*; D006801:Humans; D019216:Metals, Heavy / Q000737:chemistry / Q000378:metabolism; D009369:Neoplasms / Q000517:prevention & control*; D012275:Oryza / Q000737:chemistry* / Q000378:metabolism; D018515:Plant Leaves / Q000737:chemistry / Q000378:metabolism; D018547:Plant Stems / Q000737:chemistry / Q000378:metabolism; D012307:Risk Factors; D012639:Seeds / Q000737:chemistry / Q000378:metabolism; D012722:Sewage / Q000737:chemistry; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000737:chemistry / Q000633:toxicity*
chemical_list: D019216:Metals, Heavy; D012722:Sewage; D012987:Soil; D012989:Soil Pollutants; C540010:biochar; D002606:Charcoal
keywords: As speciation; Bioaccumulation; Biochar; Cancer risk; Daily intake; Metals; Rice