Improving Cd risk managements of rice cropping system by integrating source-soil-rice-human chain for a typical intensive industrial and agricultural region

Cadmium (Cd) accumulation in rice (Oryza sativa L.) leads to a large number of human health risks. To better understand the critical processes of Cd-related health risks and to inform mitigation policies, an assessment method was integrated by coupling source-soil-rice-human systems with anthropogenic Cd sources historical survey, regional soil Cd concentration surveyed data and an extensive literature review of Cd related human diseases. This method was subsequently applied to a rapid developing industrial and agricultural area in China. Results indicated that Cd emission sources increased fourfold from 1990 to 2007, and remained high value about 140 × 103 kg yr−1 after 2008 in the study region. The Cd fluxes in 1990–2017 varied from 3.93 to 73.49 mg m−2. Raw coal consumption contributed to approximately 50% of total Cd fluxes. During 2003–2013, the annual increasing rate of soil Cd varied from −2.34 μg kg−1yr−1 to 7.94 μg kg−1yr−1 with an average 5.14 μg kg−1yr−1. Under the current industry and agriculture developing trends, farmland soil in 2030 will face significant Cd pollution risks and the average soil Cd concentration will increase to 0.35 mg kg−1 which is 1.75 times higher than that of 2003. Consequently, higher Cd concentrations were predicted in rice grain and human blood. About 3.43% of adults may have obesity and hypertension, and approximately 4.96% of children will also be the risk of physical, cognitive neurobehavioral development. The mitigation strategies of Cd source reduction and phytoremediation technology in rice system can significantly decrease Cd-related health risks. These strategies are far less effective in already heavily polluted soils. This study provides critical information on Cd emission factors, Cd related human diseases, and a novel useful tool for policy-makers on metals pollution management.