Effects of atmospheric deposition on heavy metal contamination in paddy field systems under different functional areas in ChangZhuTan, Hunan Province, China

Pengyue Yu; Xingyuan Shao; Maodi Wang; Zhen Zhu; Zhenglong Tong; Jianwei Peng; Yaocheng Deng; Ying Huang

doi:10.1016/j.scitotenv.2024.172953

Effects of atmospheric deposition on heavy metal contamination in paddy field systems under different functional areas in ChangZhuTan, Hunan Province, China

Sci Total Environ. 2024 May 10:933:172953. doi: 10.1016/j.scitotenv.2024.172953. Online ahead of print.

Authors

Pengyue Yu¹, Xingyuan Shao¹, Maodi Wang¹, Zhen Zhu¹, Zhenglong Tong¹, Jianwei Peng¹, Yaocheng Deng², Ying Huang³

Affiliations

¹ National Engineering Laboratory of High Efficient Use on Soil and Fertilizer, College of Resources, Hunan Agricultural University, Changsha 410128, China.
² College of Environment & Ecology, Hunan Agricultural University, Changsha 410128, China. Electronic address: dengyaocheng@hunau.edu.cn.
³ National Engineering Laboratory of High Efficient Use on Soil and Fertilizer, College of Resources, Hunan Agricultural University, Changsha 410128, China. Electronic address: huangying@hunau.edu.cn.

PMID: 38734112
DOI: 10.1016/j.scitotenv.2024.172953

Abstract

In recent decades, the problem of heavy metal contamination in rice paddies has attracted widespread attention. However, most studies on heavy metal contamination in paddy fields are biased towards soil and/or rice plants, without taking atmospheric deposition into account. In this study, atmospheric deposition, paddy soil, and rice samples were collected from three functional areas (area proximity to factories, along the roadside, and suburban) in ChangZhuTan, Hunan Province. The pollution characterization, translocation, and health risk of heavy metals were reassessed. The findings revealed that Cd and As contamination in the study area's soils was more severe, with point exceedance rates reaching 70 % and 35.9 %, respectively. The highest concentrations of As, Ni, Cd, and Pb in atmospheric deposition were found along the roadside, with 1.42 μg/m²/day, 3.21 μg/m²/day, 0.34 μg/m²/day, and 8.28 μg/m²/day, respectively. In area proximity to factories, As and Ni in atmospheric deposition showed to be lowest, whereas Cd and Pb concentrations showed lowest in suburban areas. Furthermore, the accumulation of Cd and Pb in rice grains in regions proximity to factories was significantly higher than in other regions. The human health risk assessment indicated the health risk caused by rice intake in areas proximity to factories was the highest and requires attention, which was mainly due to Cd accumulation, with HQ value reached 3.19. Correlation tests indicate that atmospheric deposition has a positive effect on heavy metal enrichment in rice grains. Further Random Forest analysis revealed that the transport of heavy metals from atmospheric deposition to leaves and shells were important influencing factors for As, Cd, Ni and Mg accumulation in rice grain. Therefore, more attention should be paid to the effects of atmospheric deposition on the accumulation of heavy metals in paddy fields in order to maintain the production safety of crops.

Keywords: Cadmium; Foliar uptake; Potential health risk assessment; Rice; Translocation.