Disinfection Byproducts in Drinking Water and Evaluation of Potential Health Risks of Long-Term Exposure in Nigeria

Abstract

Levels of trihalomethanes (THMs) in drinking water from water treatment plants (WTPs) in Nigeria were studied using a gas chromatograph (GC Agilent 7890A with autosampler Agilent 7683B) equipped with electron capture detector (ECD). The mean concentrations of the trihalomethanes ranged from zero in raw water samples to 950 μg/L in treated water samples. Average concentration values of THMs in primary and secondary disinfection samples exceeded the standard maximum contaminant levels. Results for the average THMs concentrations followed the order TCM > BDCM > DBCM > TBM. EPA-developed models were adopted for the estimation of chronic daily intakes (CDI) and excess cancer incidence through ingestion pathway. Higher average intake was observed in adults (4.52 × 10−2 mg/kg-day), while the ingestion in children (3.99 × 10−2 mg/kg-day) showed comparable values. The total lifetime cancer incidence rate was relatively higher in adults than children with median values 244 and 199 times the negligible risk level.

Evaluation of Human Health Risks Associated with Exposure to Disinfection by-Products (Dbps) in Drinking Water of Wassit Province Southeast Iraq

“…The second approved risk assistant model was the US.EPA approved risk assistant model which adopted by many researchers (14,15,16,17). Carcinogenic risks resulted from the exposure to both THMs and HAAs concentrations were calculated using the US.EPA method.…”

Occurrence of disinfectant by‐products in desalinated drinking water in Egypt

“…Total organic halogen (TOX), a measure of the total concentration of halogenated materials in water (Hua et al , 2006; Kristiana et al , 2015), presents a strategy for water industry and regulators to estimate and quantify all halogen incorporation into DBPs to better protect the public health from the probable health risks (Richardson et al , 2007). Although advanced analytical techniques have significantly increased the group of DBPs with different structures and molecular weights, the sum of detected halogenated DBPs even now represent noticeably less than 50% of TOX produced by the chlorination of water (Barrett et al , 2000; Krasner et al , 2006; Benson et al , 2017), revealing that an important part of halogenated DBPs continue to be unknown or unidentified (Savitz et al , 2006; Itoh et al , 2011; Pan and Zhang, 2013; Liu et al , 2017; Li and Mitch, 2018). Trihalomethanes (THMs) and haloacetic acids (HAAs) are the most studied DBPs in desalinated and blended water (Kim et al , 2015).…”

Humic Acid Removal by Electrocoagulation Process from Natural Aqueous Environments

“…These problems include creating adverse aesthetic effects corresponding to color, taste, and odor in drinking water [5,6], transportation of toxic metals [3,7], Reducing the desired effect of water treatment processes on the pollution removal [8,9], corrosion of metallic facilities [10][11][12], adverse effects on the coagulation [13], adsorption, processes [14], adverse effect on the functionality of membranes [15], contribution to regrowth of microorganisms in water supplying systems and water storage tanks [16,17], increasing the amount of disinfecting agents utilization in water treatment processes, and more importantly, during the water disinfection process, humic acid compounds may react with the disinfecting agents and result in production of over 600 types of disinfecting agent byproducts such as THMs and HAAs which could cause cancers naming bladder and intestine cancers as the most important ones [18][19]. Currently, the paramount reason stated for removal of these compounds from water is acetic acids (HAAs), the threshold limit values of which are determined as 60 µg/L and 80 µg/L in drinking water at the first stage of applying the regulations and 30 µg/L and 40 µg/L at the second sage by United States Environmental Protection Agency [20]. The World Health Organization has also set the threshold limit value of THMs in drinking water as 100 µg/L [21].…”