Espigares Miguel, Lardelli Pablo, Ortega Pedro
Department of Preventive Medicine and Public Health, University of Granada, School of Pharmacy, Campus Universitario de Cartuja, Granada E-18071, Spain.
J Environ Health. 2003 Oct;66(3):9-13, 20.
The presence of trihalomethanes (THMs) in potable-water sources is an issue of great interest because of the negative impact THMs have on human health. The objective of this study was to correlate the presence of trihalomethanes with more routinely monitored parameters of water quality, in order to facilitate THM control. Water samples taken at various stages of treatment from a water treatment plant were analyzed for the presence of trihalomethanes with the Fujiwara method. The data collected from these determinations were compared with the values obtained for free-residual-chlorine and combined-residual-chlorine levels as well as standard physico-chemical and microbiological indicators such as chemical oxygen demand (by the KMnO4 method), total chlorophyll, conductivity, pH, alkalinity, turbidity, chlorides, sulfates, nitrates, nitrites, phosphates, ammonia, calcium, magnesium, heterotrophic bacteria count, Pseudomonas spp., total and fecal coliforms, and fecal streptococci. The data from these determinations were compiled, and statistical analysis was performed to determine which variables correlate best with the presence and quantity of trihalomethanes in the samples. Levels of THMs in water seem to correlate directly with levels of combined residual chlorine and nitrates, and inversely with the level of free residual chlorine. Statistical analysis with multiple linear regression was conducted to determine the best-fitting models. The models chosen incorporate between two and four independent variables and include chemical oxygen demand, nitrites, and ammonia. These indicators, which are commonly determined during the water treatment process, demonstrate the strongest correlation with the levels of trihalomethanes in water and offer great utility as an accessible method for THM detection and control.
由于三卤甲烷（THMs）对人体健康有负面影响，饮用水源中三卤甲烷的存在是一个备受关注的问题。本研究的目的是将三卤甲烷的存在与更常规监测的水质参数相关联，以便于控制三卤甲烷。采用藤原法分析了从一家水处理厂不同处理阶段采集的水样中三卤甲烷的存在情况。将这些测定收集的数据与游离余氯和化合余氯水平以及标准理化和微生物指标（如化学需氧量（采用高锰酸钾法）、总叶绿素、电导率、pH值、碱度、浊度、氯化物、硫酸盐、硝酸盐、亚硝酸盐、磷酸盐、氨、钙、镁、异养细菌计数、假单胞菌属、总大肠菌群和粪大肠菌群以及粪链球菌）所获得的值进行比较。对这些测定的数据进行整理，并进行统计分析，以确定哪些变量与样品中三卤甲烷的存在和数量最相关。水中三卤甲烷的水平似乎与化合余氯和硝酸盐的水平直接相关，而与游离余氯的水平呈负相关。进行了多元线性回归统计分析以确定最佳拟合模型。所选模型包含两个至四个自变量，包括化学需氧量、亚硝酸盐和氨。这些指标在水处理过程中通常会被测定，它们与水中三卤甲烷的水平显示出最强的相关性，并作为一种可获取的三卤甲烷检测和控制方法具有很大的实用性。
