Simmons G, Hope V, Lewis G, Whitmore J, Gao W
Auckland Healthcare Public Health Protection, Private Bag 92 605, Symonds St, Auckland, New Zealand.
Water Res. 2001 Apr;35(6):1518-24. doi: 10.1016/s0043-1354(00)00420-6.
One-hundred and twenty-five domestic roof-collected rainwater supplies in four rural Auckland districts were investigated in a cross-sectional survey to determine water quality. Samples of cold faucet water were analysed for physico-chemical and microbiological determinands, including metals (zinc, copper and lead), bacterial indicator organisms--heterotrophic plate count (HPC), total coilforms (TC), faecal coliforms (FC), enterococci (ENT), bacterial pathogens including Salmonella spp., Legionella spp., Campylobacter spp., Aeromonas spp. and the protozoa, Cryptosporidium and Giardia. Twenty-two supplies (17.6%) exceeded one or more of the maximum acceptable values (MAV) or maximum guideline values for chemical determinands of the New Zealand Drinking Water Standards (NZDWS) and 70 (56.0%) supplies exceeded the microbiological criteria of < 1 FC/100 mL. Eighteen supplies (14.4%) exceeded the NZDWS MAV for lead of 0.01 mg/L and three (2.4%) exceeded that for copper, of 2 mg/L. Those supplies with lead or galvanised iron comprising part of the roof or collecting system were more likely to show lead contamination (p = 0.019) as were those supplies with a pH less than 7 (p = 0.013). The presence of the indicator organisms HPC, TC, FC and ENT were all significantly correlated with one another. Aeromonas spp. were identified in 20 (16.0%) supplies. There was a positive association between the presence of Aeromonas and the bacterial indicator organisms. Households reporting at least one member with gastrointestinal symptoms in the month prior to sampling, were more likely to have Aeromonas spp. identified in their water supply than those households without symptoms (odds ratio 3.22, 95% CI 1.15-9.01, p = 0.021). Salmonella typhimurium was detected in one of 115 (0.9%) supplies. Legionella spp. and Campylobacter spp. were not detected. There were 50 supplies sampled for protozoa (sampling criteria: > or = 30 FC or > or = 60 ENT). Cryptosporidium oocysts were detected in 2 (4%) of these. Giardia was not detected. This study demonstrates that roof-collected rainwater systems provide potable supplies of relatively poor physiochemical and microbiological quality in the Auckland area. Further research is required on Aeromonas spp. as potential indicators of both microbiological quality and health risk along with design and maintenance strategies to minimise contamination of potable roof-collected rainwater supplies.
在一项横断面调查中，对奥克兰四个农村地区的125个家庭屋顶收集雨水供应进行了调查，以确定水质。分析了冷水龙头水的物理化学和微生物指标，包括金属（锌、铜和铅）、细菌指示生物——异养平板计数（HPC）、总大肠菌群（TC）、粪大肠菌群（FC）、肠球菌（ENT）、细菌病原体，包括沙门氏菌属、军团菌属、弯曲杆菌属、气单胞菌属以及原生动物隐孢子虫和贾第虫。22个供应源（17.6%）超过了新西兰饮用水标准（NZDWS）化学指标的一个或多个最大可接受值（MAV）或最大指导值，70个供应源（56.0%）超过了微生物标准<1 FC/100 mL。18个供应源（14.4%）超过了NZDWS铅的MAV 0.01 mg/L，3个（2.4%）超过了铜的MAV 2 mg/L。屋顶或收集系统部分由铅或镀锌铁组成的那些供应源更有可能显示铅污染（p = 0.019），pH值小于7的那些供应源也是如此（p = 0.013）。指示生物HPC、TC、FC和ENT的存在彼此之间都显著相关。在20个（16.0%）供应源中鉴定出气单胞菌属。气单胞菌的存在与细菌指示生物之间存在正相关。在采样前一个月报告至少有一名家庭成员有胃肠道症状的家庭，其供水系统中比没有症状的家庭更有可能鉴定出气单胞菌属（优势比3.22，95%可信区间1.15 - 9.01，p = 0.021）。在115个供应源中的1个（0.9%）中检测到鼠伤寒沙门氏菌。未检测到军团菌属和弯曲杆菌属。对50个供应源进行了原生动物采样（采样标准：≥30 FC或≥60 ENT）。在其中2个（4%）中检测到隐孢子虫卵囊。未检测到贾第虫。这项研究表明，在奥克兰地区，屋顶收集雨水系统提供的饮用水在物理化学和微生物质量方面相对较差。需要对气单胞菌属作为微生物质量和健康风险的潜在指标以及设计和维护策略进行进一步研究，以尽量减少屋顶收集的饮用水供应的污染。
