# Innovative Approaches for Minimizing Disinfection
## 3 DBPs
### Health Effects of DBPs  
C-DBPs in tap water raise significant concerns due to their suspected carcinogenic properties [3]. Epidemiological and toxicity studies have linked prolonged consumption of chlorinated water to adverse health effects, including spontaneous abortions, congenital disabilities, and an elevated risk of gastrointestinal and urinary tract cancers. DBPs have various harmful effects, including cytotoxicity, mutagenicity, genotoxicity, carcinogenicity, and teratogenicity, posing significant health risks through different exposure routes. They have diverse precursors, including humic acid, carbohydrates, lipids, and amino acids [1,13]. Additionally, DBPs discharged into the natural aquatic environment can be toxic to aquatic organisms, such as zooplankton, algae, crustaceans, fish, and others [4]. Exposure to DBPs in drinking water over a long period, whether through drinking, breathing, or skin contact, raises the likelihood of adverse health outcomes. The International Agency for Research on Cancer (IARC) classifies specific forms of THMs and HAAs as Group 2B, indicating a potential heightened risk of liver cancer [10]. Research indicates a link between prolonged exposure to high concentrations of THMs in drinking water and a higher likelihood of developing bladder cancer. Additionally, such exposure could potentially lead to reproductive and growth-related impacts. The mechanism is believed to be related to the carcinogenic properties of certain THM compounds [14]. Furthermore, the genotoxic and overall toxic properties of more than 100 DBPs have been identified by examining thousands of water samples. Further, 22 DBPs (excluding various nitrosamines) have been subject to cancer assessments in rodent studies [14]. As a typical N-DBP, dihaloacetonitrile (DCAN) exhibits higher levels of cytotoxicity and genotoxicity when compared to other prevalent DBPs [15]. Looking back at the history of DBPs, the initial discoveries revolved around volatile compounds. In 1974, chloroform was the first DBP discovered among the volatile compounds in treated drinking water. By 1976, its link to hepatocellular carcinomas in mice and renal tumors in rats raised considerable alarm about the possible health effects of DBPs. This led to regulatory measures by the United States Environmental Protection Agency (USEPA) in 1979, targeting a group of volatile DBPs with similar structures, including THMs like bromodichloromethane and dibromochloromethane [9]. In 1986, the USEPA suggested establishing a maximum contaminant level (MCL) of 80 mg L\({}^{-1}\) for four THMs as part of Stage I regulations, aiming to later reduce it to 40 mg L\({}^{-1}\) under Stage II guidelines to mitigate human health hazards. They also enforced a cap of 60 mg L\({}^{-1}\) on HAAs, encompassing the combined concentration of five species in treated water. In contrast, the United Kingdom and the European Union set the limit for THMs at 100 mg L\({}^{-1}\)[6]. After over 40 years of research, more than 800 DBPs have been identified [1; 16]. There is a reasonably good understanding of the mechanisms behind their formation and the concentrations at which they occur. Several treatment and disinfection methods have been developed and put into practice to reduce DBP levels while ensuring the safety of drinking water from a microbiological standpoint. Most developed nations utilize advanced water treatment technologies and have established regulations or guidelines concerning DBPs. For example, the USEPA lowered the permissible concentration of the combined four THMs from 100 to 80 ug L\({}^{-1}\) and regulated seven more DBPs. As a result of these research endeavors, the potential global risk of bladder cancer linked to drinking water in many regions has likely decreased compared to previous conditions. This highlights the collaborative efforts of numerous scientists, supported by both public and private sectors, working to equip regulators with the necessary tools and knowledge to improve public health.