McLaughlin Laura A, Levy Karen, Beck Nicola K, Shin Gwy-Am, Meschke J Scott, Eisenberg Joseph N
University of Washington, Seattle, WA 98195, USA.
J Environ Health. 2009 Apr;71(8):48-53.
Although the efficacy of chlorine disinfection under controlled laboratory conditions is well known, the effectiveness of chlorine under field point-of-use (POU) conditions is still not clearly understood and may be impacted by a variety of factors. This study evaluated the effectiveness of POU chlorine disinfection in rural Ecuador under typical use conditions and compared this effectiveness with the efficacy in controlled laboratory conditions. While reductions of indicator organisms were slightly higher in households that used chlorination, no significant differences were seen between households employing POU chlorination and the households with no chlorination (1-1.5 log10 median reductions for chlorinating households and 0.31-0.55 log10 for nonchlorinating households, depending on the indicator organism). In contrast, significant reduction of all test organisms was found when simulating POU conditions in the laboratory. This study demonstrates that POU chlorination can be considerably less effective under actual field conditions than would be predicted based on its laboratory efficacy (3-5 log10 median reductions for chlorinated and 0-0.3 log10 for nonchlorinated samples). Human factors (including improper storage and chlorine dosing) and uncontrolled water quality effects are hypothesized to impact significantly the effectiveness of chlorine disinfection.
虽然在实验室控制条件下氯消毒的效果是众所周知的，但在现场使用点（POU）条件下氯的有效性仍未得到清楚了解，并且可能受到多种因素的影响。本研究评估了在典型使用条件下厄瓜多尔农村地区POU氯消毒的有效性，并将该有效性与实验室控制条件下的效果进行了比较。虽然使用氯化处理的家庭中指示微生物的减少量略高，但采用POU氯化处理的家庭与未进行氯化处理的家庭之间未观察到显著差异（根据指示微生物的不同，氯化处理家庭的中位数减少量为1 - 1.5个对数10，未氯化处理家庭为0.31 - 0.55个对数10）。相比之下，在实验室模拟POU条件时，所有测试微生物都有显著减少。本研究表明，POU氯化处理在实际现场条件下的效果可能比根据其实验室效果预测的要低得多（氯化处理样本的中位数减少量为3 - 5个对数10，未氯化处理样本为0 - 0.3个对数10）。据推测，人为因素（包括储存不当和氯投加量不当）以及不受控制的水质影响会显著影响氯消毒的效果。
