Biochar amendment mitigates the health risks of dietary methylmercury exposure from rice consumption in mercury-contaminated areas. (December 2020)

• Record Type: Journal Article
• Authors: Wang, Yongjie; Sun, Yafei; He, Tianrong; Deng, Hong; Wang, Zhigang; Wang, Jiangtao; Zheng, Xiangmin; Zhou, Limin; Zhong, Huan
• Is Part Of: Environmental pollution. Volume 267(2020)
• Publication Date: 2020-12
• Subjects: Paddy soils -- Methylmercury -- Biochar -- Health risks; Pollution -- Periodicals; Pollution -- Environmental aspects -- Periodicals; Environmental Pollution -- Periodicals; Pollution -- Périodiques; Pollution -- Aspect de l'environnement -- Périodiques; Pollution -- Effets physiologiques -- Périodiques; Pollution; Pollution -- Environmental aspects; Periodicals; Electronic journals; 363.73
• DOI: 10.1016/j.envpol.2020.115547
• Languages: English
• ISSNs: 0269-7491

Abstract

Abstract: The accumulation of methylmercury (MeHg) in rice is an important MeHg exposure pathway in humans in several mercury (Hg)-contaminated areas. In this study, the effects of low-dose biochar (BC) amendment (0.3%, w/w) on MeHg mobility/phytoavailability in different Hg-contaminated paddy soils, MeHg accumulation in rice plants and the health risks associated with MeHg-laden rice consumption were investigated. Soils amended with different doses of bamboo-derived BC (0.3, 0.5, and 1%, w/w) were incubated under anoxic conditions in microcosm experiments. In addition, pot experiments were conducted involving rice cultivation with a low BC application rate (0.3%, w/w). We observed that (1) the fraction of extractable MeHg in soils decreased with BC addition in both the microcosm and pot experiments; (2) MeHg concentrations in the rice grains (brown rice) significantly decreased by 56–88% in response to BC amendment, which may be attributed mainly to decreases in MeHg mobility/phytoavailability in the soil; and (3) the hazard quotient (HQ) values for adults and children and fetal intelligence quotient (IQ) decrements associated with MeHg-laden rice consumption were significantly alleviated under BC amendment. Taken together, our findings suggest that a low dose of BC (0.3%, w/w) could have great potential for mitigating the health risks of dietary MeHg exposure from the consumption of rice grown in mercury (Hg)-contaminated areas. Graphical abstract: Image 1 Highlights: Methylmercury (MeHg) mobility in soils decreased with biochar (BC) addition. A low application rate (0.3% of soil mass) of BC reduced MeHg accumulation in rice grains. BC amendment can mitigate the health risks of dietary MeHg exposure from rice consumption. Abstract : BC amendment can lead to a reduction both in the average daily intake of MeHg via rice consumption and in a variety of health risks.