A new method of predicting the contribution of TGM to Hg in white rice: Using leaf THg and implications for Hg risk control in Wanshan Hg mine area. (1st November 2021)

• Record Type: Journal Article
• Authors: Chang, Chuanyu; Yin, Runsheng; Huang, Fang; Wang, Ruirui; Chen, Chongying; Mao, Kang; Feng, Xinbin; Zhang, Hua
• Is Part Of: Environmental pollution. Volume 288(2021)
• Publication Date: 2021-11-01
• Subjects: TGM -- Soil -- Contribution -- Rice -- Wanshan Hg mine; 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.2021.117727
• Languages: English
• ISSNs: 0269-7491

Abstract

Abstract: Rice plants accumulate Hg from the soil and ambient air, however, evaluating the contribution of Hg from these two sources remains challenging. Here, we proposed a practical method to predict the contribution of total gaseous mercury (TGM) to Hg in white rice in Wanshan Hg mine area (WMM). In this study, rice was planted in the same low-Hg soil at different sites of WMM with varying TGM levels. Comparing to the control sites at IG (Institute of Geochemistry, Guiyang), TGM is the dominant source of Hg in rice leaves and white rice at TB (Tianba) and ZJW (Zhangjiawan) sites of WMM. Subsequently, a good correlation between the Hg concentrations in rice leaves and the concentration contributions of TGM to Hg in white rice was obtained. Such a correlation enabled feasible quantification of the contribution of TGM to Hg in white rice collected from the Wanshan Hg mine. The contribution of TGM to Hg in white rice across the WMM area was also estimated, demonstrating that white rice receives 14–83% of Hg from the air. Considering the high contribution of TGM to Hg in white rice, we compared the relative health risks of Hg via inhalation and rice consumption and found that inhalation, rather than rice consumption, was the major pathway for bioaccessible Hg exposure in adults at high-TGM sites. This study provides new knowledge of Hg biogeochemistry in Hg-mining areas. Graphical abstract: Image 1 Highlights: Leaf THg is used to predict the contribution of TGM to IHg in white rice at WMM. TGM contributes to 14%–83% of IHg in rice in the WMM area. Inhalation is the major pathway for bioaccessible THg intake at the high-TGM sites.