Arsenic Concentrations in Paddy Soil and Rice and Health Implications for Major Rice-Growing Regions of Cambodia

• Published in: Environmental science & technology 2014-05, Vol.48 (9), p.4699-4706
• Main Authors: Seyfferth, Angelia L, McCurdy, Sarah, Schaefer, Michael V, Fendorf, Scott
• Format: Article
• Language: English
• Subjects: Agronomy. Soil science and plant productions; Air. Soil. Water. Waste. Feeding; Applied sciences; Arsenic - analysis; Arsenic content; Biological and medical sciences; Biological and physicochemical properties of pollutants. Interaction in the soil; Cambodia; Crops, Agricultural - chemistry; Earth sciences; Earth, ocean, space; Engineering and environment geology. Geothermics; Environment. Living conditions; Environmental Exposure; Environmental Monitoring; Exact sciences and technology; Food Contamination - analysis; Fundamental and applied biological sciences. Psychology; Groundwater; Humans; Iron - analysis; Irrigation; Medical sciences; Oryza - chemistry; Oryza sativa; Phosphorus - analysis; Pollution; Pollution, environment geology; Public health. Hygiene; Public health. Hygiene-occupational medicine; Rice; Sediments; Silicon - analysis; Soil and sediments pollution; Soil and water pollution; Soil Pollutants - analysis; Soil science; Soil sciences; Spectrophotometry, Atomic; Water Pollutants, Chemical - analysis
• ISSN: 0013-936X; 1520-5851
• DOI: 10.1021/es405016t

Despite the global importance of As in rice, research has primarily focused on Bangladesh, India, China, and the United States with limited attention given to other countries. Owing to both indigenous As within the soil and the possible increases arising from the onset of irrigation with groundwater, an assessment of As in rice within Cambodia is needed, which offers a “base-case” comparison against sediments of similar origin that comprise rice paddy soils where As-contaminated water is used for irrigation (e.g., Bangladesh). Here, we evaluated the As content of rice from five provinces (Kandal, Prey Veng, Battambang, Banteay Meanchey, and Kampong Thom) in the rice-growing regions of Cambodia and coupled that data to soil-chemical factors based on extractions of paddy soil collected and processed under anoxic conditions. At total soil As concentrations ranging 0.8 to 18 μg g–1, total grain As concentrations averaged 0.2 μg g–1 and ranged from 0.1 to 0.37 with Banteay Meanchey rice having significantly higher values than Prey Veng rice. Overall, soil-extractable concentrations of As, Fe, P, and Si and total As were poor predictors of grain As concentrations. While biogeochemical factors leading to reduction of As­(V)-bearing Fe­(III) oxides are likely most important for predicting plant-available As, husk and straw As concentrations were the most significant predictors of grain-As levels among our measured parameters.