DrinkingWater Disinfection By-products and Their Carcinogenicity, A Review of Unseen Crisis

Context: Cancer continues to be the first cause of mortality and morbidity all over the world, while the incidence of cancer is expected to increase by 50% over the next 20 years. Since the incidence of most of the cancers is increasing daily, it has been more important to find related environmental risk factors. The epidemiological evidence indicates the effect of disinfection byproducts (DBPs) through drinking water, as an environmental exposure, on most of the cancers. The goal of the current study was to combine the results of most recent publications regarding the relationship between DBPs and their carcinogenic effects. Evidence Acquisition: Using the main keywords of “cancer”, “drinking water”, and “disinfection byproducts”, a comprehensive search was done among several research databases. Results: Based on the previous studies, DBPs could cause most types of cancers, mainly including gastrointestinal, renal, bladder, breast, liver, and thyroid cancers. Liver and renal cancers are the most common target organs for toxicity by DBPs. Among the various DBPs, trihalomethanes are the most studied due to their relatively high prevalence and concentration in drinking water. Also, haloacetic acids, such as trichloroacetic acid and dichloroacetic acid, have been known as one of the most affecting risk factors. Unregulated DBPs, such as Mutagen X and Formaldehyde, are also of importance as they mostly have irreversible systemic effects. Providing safe drinking water resources, restriction of unreasonable usage of disinfectants, and alternating disinfectants with less harmful products could be the possible ways to overcome this crisis. Conclusions: Disinfection byproducts can result in cancer development, especially in liver and kidneys. Providing safe drinking water resources, using the membrane filters and changing the chlorination point are effective ways to encounter the risk of DBP poisoning.