The researchers studied the presence of six haloacetamides in drinking water in Japan, which are byproducts of water disinfection. They found that these compounds were present in all samples, with concentrations ranging from 0.3 to 3.8 μg/L. The most common haloacetamides detected were 2,2-dichloroacetamide and 2-bromo-2-chloroacetamide. The levels of these compounds increased with longer chlorination times and were influenced by the pH of the water. The study also found a correlation between the concentrations of haloacetamides and trihalomethanes in the water.