Meharg Andrew A, Rahman Md Mazibur
School of Biological Sciences, University of Aberdeen, Cruickshank Building, St. Machar Drive, Aberdeen, AB24 3UU, UK.
Environ Sci Technol. 2003 Jan 15;37(2):229-34. doi: 10.1021/es0259842.
Arsenic contaminated groundwater is used extensively in Bangladesh to irrigate the staple food of the region, paddy rice (Oryza sativa L.). To determine if this irrigation has led to a buildup of arsenic levels in paddy fields, and the consequences for arsenic exposure through rice ingestion, a survey of arsenic levels in paddy soils and rice grain was undertaken. Survey of paddy soils throughout Bangladesh showed that arsenic levels were elevated in zones where arsenic in groundwater used for irrigation was high, and where these tube-wells have been in operation for the longest period of time. Regression of soil arsenic levels with tube-well age was significant. Arsenic levels reached 46 microg g(-1) dry weight in the most affected zone, compared to levels below l0 microg g(-1) in areas with low levels of arsenic in the groundwater. Arsenic levels in rice grain from an area of Bangladesh with low levels of arsenic in groundwaters and in paddy soils showed that levels were typical of other regions of the world. Modeling determined, even these typical grain arsenic levels contributed considerably to arsenic ingestion when drinking water contained the elevated quantity of 0.1 mg L(-1). Arsenic levels in rice can be further elevated in rice growing on arsenic contaminated soils, potentially greatly increasing arsenic exposure of the Bangladesh population. Rice grain grown in the regions where arsenic is building up in the soil had high arsenic concentrations, with three rice grain samples having levels above 1.7 microg g(-1).
在孟加拉国，人们广泛使用受砷污染的地下水来灌溉该地区的主食——水稻（Oryza sativa L.）。为了确定这种灌溉方式是否导致稻田中的砷含量增加，以及通过食用大米摄入砷的后果，我们对稻田土壤和稻米中的砷含量进行了一项调查。对孟加拉国各地稻田土壤的调查显示，在用于灌溉的地下水中砷含量高且这些管井运行时间最长的区域，土壤中的砷含量有所升高。土壤砷含量与管井使用年限的回归分析具有显著性。在受影响最严重的区域，土壤砷含量达到46微克/克干重，而在地下水中砷含量低的地区，该含量低于10微克/克。孟加拉国一个地下水和稻田土壤中砷含量低的地区的稻米砷含量表明，其水平与世界其他地区的典型水平相当。模型分析确定，即使是这些典型的稻米砷含量，当饮用水中砷含量升高至0.1毫克/升时，也会对砷的摄入量有相当大的贡献。在受砷污染土壤上种植的水稻中，砷含量可能会进一步升高，这可能会大大增加孟加拉国人口的砷暴露量。在土壤中砷含量不断累积的地区种植的稻米砷浓度很高，有三个稻米样本的含量超过了1.7微克/克。
