Department of Agricultural Chemistry, National Taiwan University, No. 1, Sec. 4, Roosevelt Rd., Taipei 10617, Taiwan.
Department of Agricultural Chemistry, National Taiwan University, No. 1, Sec. 4, Roosevelt Rd., Taipei 10617, Taiwan.
J Hazard Mater. 2015 Apr 9;286:179-86. doi: 10.1016/j.jhazmat.2014.12.052. Epub 2015 Jan 8.
Rice consumption is a major route of As exposure to human for the population of worldwide. This study investigates the effect of phytotoxicity and rice genotypes on the content and speciation of As in rice grains grown in different levels of As-elevated paddy soils from Taiwan. Three levels of As-elevated soils and six rice genotypes commonly planted in Taiwan were used for this study. The results indicate that As contents in grains of rice is not proportional to soil As concentrations and they were equal or higher in indica genotypes than japonica genotypes used in this study. It was also found that the As phytotoxicity not only reducing the grain yields but also the As concentrations in grain of rice. The predominant As species found in rice grains were dimethylarsinic acid (DMA) and arsenite. The concentrations of DMA increased with total As concentrations, wherggeas the arsenite remained in a narrow range from 0.1 to 0.3 mg kg(-1). Because of the lower toxicity of DMA than inorganic As species, the health risks may not be increased through consumption of rice even when total As content in the grains is increased.
大米消费是全世界人类摄入砷的主要途径。本研究调查了在台湾不同砷污染稻田土壤中种植的不同水稻品种对砷在稻米中含量和形态的影响。本研究使用了三种砷污染土壤水平和六种在台湾常见的水稻品种。结果表明，稻米中砷的含量与土壤砷浓度不成比例，而且在所研究的籼稻品种中，其含量与在本研究中使用的粳稻品种相同或更高。还发现，砷的植物毒性不仅降低了稻谷产量，而且还降低了稻米中的砷浓度。在稻米籽粒中发现的主要砷形态是二甲基砷酸（DMA）和亚砷酸盐。DMA 的浓度随着总砷浓度的增加而增加，而亚砷酸盐的浓度则保持在 0.1 至 0.3mg/kg 的狭窄范围内。由于 DMA 的毒性比无机砷形态低，因此即使谷物中的总砷含量增加，通过食用大米摄入的健康风险也可能不会增加。
