Department of Fisheries and Wildlife, Michigan State University, East Lansing, MI 48824, USA.
Water Res. 2011 Dec 1;45(19):6505-14. doi: 10.1016/j.watres.2011.09.047. Epub 2011 Oct 14.
Recreational outbreaks associated with sprayparks are well recognized, and may be partly due to the engineering designs used for their water reclamation systems are problematic to control. This work is based on an outbreak of cryptosporidiosis linked to a spraypark in New York State, where it was determined, specifically that the spraypad (the main attraction) was the primary exposure point. We first determined the likely dose the spraypad users were exposed to, then modeled the efficacy of the treatment system and used this to inform a Monte Carlo method to estimate the probability of infection and illness for the users of the spraypad. The current treatment system which consists of; two holding tanks, a dual media filter and chlorine injection as well as two design change recommendations were modeled using three independent Markov chain models. Within the current treatment system design the receiving tank for the treatment train is also connected with a second pipe to the spraypad used to deliver the return (treated) water, this return pipe is acting potentially as a bypass for the treatment train. Based on the risk assessments performed it is recommended that the bypass pipe be removed from the treatment system since in doing so the probability of infection and illness were reduced appreciably. Secondarily including an ozone contactor was shown to slightly reduce the risk further and provide a multiple barrier.
人们已经认识到与喷雾公园有关的娱乐性爆发，这可能部分是由于用于其水回收系统的工程设计难以控制。这项工作基于与纽约州一个喷雾公园有关的隐孢子虫病爆发，具体来说，是确定了喷雾垫（主要景点）是主要的暴露点。我们首先确定了喷雾垫使用者可能接触的剂量，然后对处理系统的效果进行建模，并使用该模型通过蒙特卡罗方法来估计喷雾垫使用者感染和患病的概率。当前的处理系统由两个储水箱、一个双介质过滤器和氯气注入以及两个设计变更建议组成，使用三个独立的马尔可夫链模型进行建模。在当前的处理系统设计中，处理系统的接收水箱也通过第二根管道连接到喷雾垫，用于输送回用水（处理后的水），该回用水管道可能作为处理系统的旁路。根据进行的风险评估，建议从处理系统中移除旁路管道，因为这样做会大大降低感染和患病的概率。其次，包括臭氧接触器被证明可以进一步降低风险，并提供多重屏障。
