Nitrosamines in Drinking Water and Surface Water in Wuhan During the COVID-19 Outbreak

The extensive use of disinfectants during the coronavirus disease 2019 (COVID-19) outbreak may have generated disinfection by-products (DBPs) in surface water and drinking water. As representative species of emerging DBPs, nitrosodimethylamine (NDMA) and seven other nitrosamines were surveyed in drinking water and surface water in Wuhan during the COVID-19 outbreak in May 2020. NDMA was predominant in surface water with an 88% detection rate. The NDMA concentration ranged from not detected to 59.4 ng/L in the Hanshui River and Yangtze River and was generally higher than that of the other target nitrosamines. The median concentrations of target nitrosamines in surface water decreased in the following order: NDMA>nitrosomethylethylamine>nitrosodibutylamine>nitrosodipropylamine. NDMA was also the predominant species in tap water, with concentrations of 143.00 ng/L (tap water 1) and 72.10 ng/L (tap water 2), one of which exceeded the 100 ng/L surface water standards of the World Health Organization and China. Using nontarget analysis and statistical analysis, a variety of pharmaceuticals and personal care products, pesticides, and industrial products were identified and could be divided into two groups (the Hanshui River and Yangtze River), which suggests that there were different distributions of these pollutants in the two rivers. None of the target DBPs were correlated with one another in surface water. NDMA posed a medium ecological risk to algae, but only at one sampling site in the Yangtze River. These DBPs may no longer be a concern because the use of disinfectants has markedly declined owing to the successful control of COVID-19.