Hudak Paul F
Department of Geography and Environmental Science Program, University of North Texas, Denton, TX 76203-5279, USA.
J Environ Sci Health A Tox Hazard Subst Environ Eng. 2004;39(11-12):2827-34.
Boron and selenium concentrations from 112 water wells in an irrigated agricultural region of south Texas were compiled, mapped, and statistically analyzed. Wells in the study area produce water from the Gulf Coast Aquifer System, comprising coastward sloping beds of clay, silt, sand, and gravel. Nearly 84 percent of boron observations exceeded the 600 ug/L advisory level for drinking water, 70% exceeded the 1250 ug/L level for sensitive crops, and 24% exceeded the 3750 ug/L level for tolerant crops. Additionally, 21% of selenium observations exceeded the 20 ug/L advisory level for irrigation water, and five percent surpassed the 50 ug/L standard for drinking water. Many wells with high boron concentrations also had high selenium concentrations, and several clusters of high concentrations were in irrigated parts of the study area. However, there was no association between selenium and well depth, and a direct rather than inverse association between boron and well depth. Progressively brackish water in downdip reaches of the aquifer largely controls observed boron patterns. Both irrigation practices and prevailing groundwater chemistry significantly influence selenium concentrations in the study area.
对得克萨斯州南部一个灌溉农业区112口水井中的硼和硒浓度进行了汇总、绘图并进行了统计分析。研究区域内的水井从墨西哥湾沿岸含水层系统取水，该系统由向海倾斜的粘土、粉砂、沙子和砾石层组成。近84%的硼观测值超过了饮用水600微克/升的建议水平，70%超过了敏感作物1250微克/升的水平，24%超过了耐受性作物3750微克/升的水平。此外，21%的硒观测值超过了灌溉用水20微克/升的建议水平，5%超过了饮用水50微克/升的标准。许多硼浓度高的水井硒浓度也高，研究区域的灌溉区有几处高浓度聚集区。然而，硒与井深之间没有关联，而硼与井深之间存在直接而非反向的关联。含水层下倾区域逐渐变咸的水在很大程度上控制了观测到的硼分布模式。灌溉方式和当地的地下水化学性质都对研究区域内的硒浓度有显著影响。
