Besser R E, Moscoso Rojas B, Cabanillas Angulo O, González Venero L, Minaya León P, Rodríguez Pajares M, Saldaña Sevilla W, Seminario Carrasco J L, Highsmith A K, Tauxe R V
University of California, Department of Pediatrics, San Diego 92103-8454, USA.
Bol Oficina Sanit Panam. 1995 Sep;119(3):189-94.
Unboiled, unchlorinated drinking water is known to have been associated with epidemic transmission of cholera in Trujillo, Peru, in February 1991. In September of that same year, chlorination of the main water supply system was begun. Water quality in Trujillo at the central level is monitored at dams and principal distribution points, but the effects of this surveillance on the quality of the water distributed are not known. In order to evaluate water quality in the residential areas of Trujillo, water samples were collected in February 1993 from 30 systematically selected houses. The chlorine levels in the samples were measured, and cultures for coliform bacteria were done. The free chlorine concentration varied from 0 to 1.5 mg/L (median = 0.4 mg/L). No free chlorine was detected in 5 samples (17%), and in 14 (47%) the concentrations were less than 0.4 mg/L. Coliforms were found in 16 samples (53%), but none were fecal coliforms. These results demonstrate the wide variability in chlorine concentrations in the municipal water that is distributed to dwellings. This variability, together with the need to store drinking water in the house because of shortages, supports the recommendation of the Ministry of Health that residents should treat drinking water in their homes. The simple sampling framework employed in this study provided a rapid evaluation of the quality of municipal water supplied to consumers. Similar studies could be carried out easily in other metropolitan areas where water quality is suspect, in order to rapidly obtain essential information on water quality at the level of the consumer.
1991年2月，在秘鲁特鲁希略，未煮沸、未加氯的饮用水被认为与霍乱的流行传播有关。同年9月，开始对主要供水系统进行氯化处理。特鲁希略市中心的水质在水坝和主要配送点进行监测，但这种监测对所配送水的质量的影响尚不清楚。为了评估特鲁希略居民区的水质，1993年2月从30所系统选取的房屋中采集了水样。测量了样本中的氯含量，并进行了大肠菌培养。游离氯浓度在0至1.5毫克/升之间（中位数为0.4毫克/升）。5个样本（17%）中未检测到游离氯，14个样本（47%）中的浓度低于0.4毫克/升。16个样本（53%）中发现了大肠菌，但均非粪大肠菌。这些结果表明，配送至住宅的市政用水中氯浓度差异很大。这种差异，再加上由于缺水需要在家中储存饮用水，支持了卫生部关于居民应在家中对饮用水进行处理的建议。本研究采用的简单抽样框架对供应给消费者的市政用水质量进行了快速评估。在其他水质可疑的大都市地区，可以轻松开展类似研究，以便迅速获取消费者层面的水质基本信息。
