Schets Franciska M, van den Berg Harold H J L, Lynch Gretta, de Rijk Sharona, de Roda Husman Ana Maria, Schijven Jack F
National Institute for Public Health and the Environment, Centre for Zoonoses and Environmental Microbiology, P.O. Box 1, 3720 BA Bilthoven, the Netherlands.
National Institute for Public Health and the Environment, Centre for Zoonoses and Environmental Microbiology, P.O. Box 1, 3720 BA Bilthoven, the Netherlands; Utrecht University, Faculty of Veterinary Medicin, Institute for Risk Assessment Sciences, Yalelaan 1, 3584 CL Utrecht, the Netherlands.
Environ Int. 2020 Apr;137:105516. doi: 10.1016/j.envint.2020.105516. Epub 2020 Jan 31.
Swimming ponds are artificial ecosystems for bathing in which people imitate the conditions of natural waters. Swimming in natural water may pose health risks if the water quality is microbiologically poor. Swimming ponds are small water bodies that may be used by relatively large groups of people, moreover, the water is not disinfected, e.g. by using chlorine. The draft new swimming pool legislation in the Netherlands includes water quality requirements for swimming ponds. This study focused on the examination and evaluation of the new microbiological water quality requirements, including Escherichia coli, intestinal enterococci, Pseudomonas aeruginosa and Staphylococcus aureus, in thirteen public swimming pools. In eight of thirteen swimming ponds the water quality met the requirements for fecal indicators; 93-95% of the samples met the requirement for E. coli (≤100/100 ml) and intestinal enterococci (≤50/100 ml). The requirement for P. aeruginosa (≤10/100 ml) was met in eleven of thirteen swimming ponds (99% of the samples). In 68% of the samples the requirement for S. aureus (<1/100 ml) was met. A linear mixed effect analysis showed that E. coli and intestinal enterococci concentrations were significantly dependent on the log of turbidity. P. aeruginosa concentrations were significantly dependent on water temperature. 31-45% of the variation between swimming ponds was explained by considering 'pond' as a random effect in the analysis. The monitoring of microbiological parameters in swimming pond water needs selective analytical methods, such as those used in this study, due to large numbers of background bacteria. The draft new Dutch swimming pool legislation provides proper guidance to ensure the microbiological safety of swimming pond water; it would benefit from inclusion of turbidity as an extra parameter. S. aureus is a relevant parameter for non-fecal shedding, although scientific literature does not provide evidence for a norm value based on a dose-response relation for exposure to S. aureus in water.
游泳池塘是供人沐浴的人工生态系统，人们在其中模拟自然水域的条件。如果自然水域的水质微生物状况不佳，在其中游泳可能会带来健康风险。游泳池塘是小型水体，可能会有相对较多的人群使用，而且水不进行消毒处理，例如不使用氯消毒。荷兰新的游泳池法规草案包含了对游泳池塘的水质要求。本研究聚焦于对13个公共游泳池塘中包括大肠杆菌、肠道肠球菌、铜绿假单胞菌和金黄色葡萄球菌在内的新微生物水质要求进行检测和评估。在13个游泳池塘中的8个，水质符合粪便指标要求；93% - 95%的样本符合大肠杆菌（≤100/100毫升）和肠道肠球菌（≤50/100毫升）的要求。13个游泳池塘中的11个（99%的样本）符合铜绿假单胞菌（≤10/100毫升）的要求。68%的样本符合金黄色葡萄球菌（<1/100毫升）的要求。线性混合效应分析表明，大肠杆菌和肠道肠球菌的浓度显著依赖于浊度的对数。铜绿假单胞菌的浓度显著依赖于水温。在分析中将“池塘”视为随机效应，解释了游泳池塘之间31% - 45%的差异。由于背景细菌数量众多，游泳池塘水微生物参数的监测需要选择性分析方法，如本研究中使用的方法。荷兰新的游泳池法规草案为确保游泳池塘水的微生物安全提供了适当指导；将浊度作为额外参数纳入会更有益。金黄色葡萄球菌是一个与非粪便排放相关的参数，尽管科学文献没有基于水中接触金黄色葡萄球菌的剂量 - 反应关系提供标准值的证据。
