关键词: 砷, 土壤-水稻系统, 形态转化, 生物有效性

Abstract: Arsenic (As) is an internationally recognized class I carcinogen, whose migration and transformation in the soil-rice system pose a continuous threat to global food security. There are diverse paddy soil types in China, with substantial variations in environmental behavior, health risks, and control effectiveness of arsenic. From the perspective of regional differences and environmental driving factors, we systematically elucidated the key processes of soil arsenic migration and transformation in four major typical agricultural ecological zones of China (southern acidic soil region, northeastern freeze-thaw region, southwestern karst region, and coastal saline-alkali region), and highlighted the core role of environmental factors such as pH, redox potential, carbonate, salinity, and freeze-thaw in jointly regulating arsenic speciation transformation and migration. The spatial pattern of arsenic accumulation in rice is high in the south and low in the north of China. Although anthropogenic factors (especially industrial and mining activities) are the main contributors to soil arsenic accumulation, rice arsenic accumulation is predominantly driven by arsenic biogeochemical processes coupled with regional environmental factors. We reviewed the regional applicability of existing control technologies, including water management, modified biochar, and microbial remediation, and explored the idea of establishing a zoned and classified precise control technology system based on process mechanisms, aiming to provide scientific references for zoned management of arsenic contamination in Chinese paddy fields and for the safe production of rice.

Key words: arsenic, soil-rice system, speciation transformation, bioavailability