potentially hazardous trihalomethanes (thms) levels in chlorinated swimming pools’ water in fars province, iran

background: trihalomethanes are toxic and dangerous substances that are formed in the presence of organic materials when water is chlorinated for disinfection. the iranian national standard, world health organization, european :union:, u.s. environmental protection agency and international agency for research in cancer standards have established a maximum contaminant level for trihalomethanes for the quality of consumable water. the aim of this study was to determine if the trihalomethanes level in the water of fars province swimming pools comply with these recommendations. methods: the laboratory study design was conducted by utilizing spectrophotometer hack dr5000 vis-uv equipment for evaluating trihalomethanes concentrations, digital photometer palin-test for measuring chlorine and ph to process different samples collected from 43 indoor and outdoor swimming pools in fars province, iran. the dependent variable was trihalomethanes and chlorine compounds were independent variables. precise laboratory experimental methods and appropriate statistical analysis were conducted using spss. results: mean concentration of trihalomethanes was found to be 242.1μg/l, ranging from 0 to 990μg/l for 43 public swimming pools in fars province. association of trihalomethanes and chlorine components with analysis of variance (anova) model was highly significant (p<0.0001). conclusion: study results showed that there were strong associations between chlorine compounds and trihalomethanes concentrations. the mean trihalomethanes was 1.2-times (241.2μg/l vs. 200.0μg/l) higher than the national and 3-folds (241.2μg/l vs. 80.0μg/l) higher than the worldwide standards. therefore, based upon standard recommendations, this conclusion could pose a hazard to public health.