van Geen A, Zheng Y, Cheng Z, He Y, Dhar R K, Garnier J M, Rose J, Seddique A, Hoque M A, Ahmed K M
Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY 10964, USA.
Sci Total Environ. 2006 Aug 31;367(2-3):769-77. doi: 10.1016/j.scitotenv.2006.01.030. Epub 2006 May 24.
Soil and soil-water As profiles were obtained from 4 rice paddies in Bangladesh during the wet growing season (May-November), when surface water with little arsenic is used for irrigation, or during the dry season (January-May), when groundwater elevated in arsenic is used instead. In the upper 5 cm of paddy soil, accumulation of 13+/-12 mg/kg acid-leachable As (n=11) was observed in soil from 3 sites irrigated with groundwater containing 80-180 microg/L As, whereas only 3+/-2 mg/kg acid-leachable As (n=8) was measured at a control site. Dissolved As concentrations averaged 370+/-340 microg/L (n=7) in the upper 5 cm of the soil at the 3 sites irrigated with groundwater containing 80-180 microg/L As, contrasting with soil water As concentrations of only 18+/-7 microg/L (n=4) over the same depth interval at the control site. Despite the accumulation of As in soil and in soil water attributable to irrigation with groundwater containing elevated As levels, there is no evidence of a proportional transfer to rice grains collected from the same sites. Digestion and analysis of individual grains of boro winter rice from the 2 sites irrigated with groundwater containing 150 and 180 microg/L As yielded concentrations of 0.28+/-0.13 mg/kg (n=12) and 0.44+/-0.25 mg/kg (n=12), respectively. The As content of winter rice from the control site was not significantly different though less variable (0.30+/-0.07; n=12). The observations suggest that exposure of the Bangladesh population to As contained in rice is less of an immediate concern than the continued use of groundwater containing elevated As levels for drinking or cooking, or other potential consequences of As accumulation in soil and soil-water.
在雨季生长季节（5月至11月），当使用含砷量低的地表水进行灌溉时，或者在旱季（1月至5月），当使用砷含量升高的地下水进行灌溉时，从孟加拉国的4块稻田获取了土壤和土壤 - 水砷（As）剖面。在稻田土壤上部5厘米处，在3个用含80 - 180微克/升砷的地下水灌溉的地点的土壤中，观察到酸可浸出砷积累量为13±12毫克/千克（n = 11），而在一个对照地点仅测得3±2毫克/千克酸可浸出砷（n = 8）。在3个用含80 - 180微克/升砷的地下水灌溉的地点，土壤上部5厘米处溶解态砷浓度平均为370±340微克/升（n = 7），而对照地点在相同深度区间的土壤水砷浓度仅为18±7微克/升（n = 4）。尽管由于使用砷含量升高的地下水灌溉导致土壤和土壤水中砷有所积累，但没有证据表明会按比例转移到从同一地点采集的稻谷中。对来自用含150和180微克/升砷的地下水灌溉的2个地点的冬季硼稻单粒进行消化和分析，得到的浓度分别为0.28±0.13毫克/千克（n = 12）和0.44±0.25毫克/千克（n = 12）。对照地点冬季稻的砷含量虽变异性较小但无显著差异（0.30±0.07；n = 12）。这些观察结果表明，与持续使用砷含量升高的地下水用于饮用、烹饪或砷在土壤和土壤水中积累的其他潜在后果相比，孟加拉国人口接触稻米中所含砷的问题并非当务之急。
