Airborne lead: A vital factor influencing rice lead accumulation in China.
JOURNAL OF HAZARDOUS MATERIALS 2022;
427:128169. [PMID:
34979386 DOI:
10.1016/j.jhazmat.2021.128169]
[Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2021] [Revised: 12/05/2021] [Accepted: 12/27/2021] [Indexed: 06/14/2023]
Abstract
Traditionally, lead (Pb) in rice grains has been thought to be mostly derived from soil, and the contribution of aerosol Pb remains so far unknown. Based on a meta-analysis, we surprisingly found rice Pb content decreased proportionally with urban atmospheric Pb concentrations in major rice-growing provinces in China during 2001-2015, suggestive of the strong influence of long-range Pb transport on agricultural environment. With the combination of field survey, field experiment, as well as a predictive model, we confirmed high contribution of atmospheric exposure to rice grain Pb in China. We for the first time developed a predictive mathematical model which revealed that aerosol Pb accumulation ratios of rice grains were related to both grain weight and accumulation types. We successfully predicted the national-scale rice Pb in China on the basis of the public data of urban PM2.5 from 19 rice-growing provinces and proposed a seasonal atmospheric Pb limit of 0.20 µg m-3 based on the safe threshold level of Pb in rice, which was much lower than the current limit of 1 µg m-3 set in China.
Collapse