National Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro, 76080, Pakistan,
Environ Monit Assess. 2014 Dec;186(12):8611-28. doi: 10.1007/s10661-014-4028-7. Epub 2014 Sep 16.
In the current study, the chemistry of fresh and stored rainwater of Thar Desert, Pakistan, was estimated during two consecutive monsoon periods. The present research deals with the variation in physicochemical parameters, total arsenic (As(t)), inorganic arsenic species (As(i), As(V), As(III)), and fluoride (F(-)) in stored rainwater (SRW) at different time intervals (1 week to 3 months). The pH of fresh rainwater (FRW) samples showed slightly acidic to neutral in nature (6.08-7.06) which were inconsistent with the reference pH value (5.6) of rainwater. The resulted data indicated that As(t) and F(-) levels in SRW were enhanced with time duration. The levels of As(t) and F(-) in SRW after different time intervals were found in the range of 194-683 μg/L and 10-35.4 mg/L, respectively. The values of As(t) and F(-) were 20-70 and 7-24 times higher than those of WHO permissible limits, 10 μg/L and 1.5 mg/L, respectively. The As(III) was dominant species in SRW, which corresponds to >60 % of As(i). The characteristics of the SRW revealed an unacceptable quality to consume for drinking and agricultural purposes in the studied area.
在当前的研究中，估计了巴基斯坦塔尔沙漠新鲜和储存雨水的化学性质，在两个连续的季风期间进行了研究。本研究涉及在不同时间间隔（1 周到 3 个月）储存雨水（SRW）中物理化学参数、总砷（As(t)）、无机砷形态（As(i)、As(V)、As(III)）和氟化物（F(-)）的变化。新鲜雨水（FRW）样品的 pH 值呈弱酸性至中性（6.08-7.06），与雨水的参考 pH 值（5.6）不一致。结果表明，SRW 中的 As(t)和 F(-)水平随时间的延长而增加。不同时间间隔后 SRW 中的 As(t)和 F(-)水平分别在 194-683μg/L 和 10-35.4mg/L 范围内。SRW 中的 As(t)和 F(-)值分别是世界卫生组织允许限值（10μg/L 和 1.5mg/L）的 20-70 倍和 7-24 倍。As(III)是 SRW 中的主要形态，占 As(i)的比例超过 60%。SRW 的特征表明，在研究区域内，其质量无法用于饮用和农业目的。
