The assessment of Haloacetic acids (HAAs) in residential tap water

Abstract

Haloacetic Acids (HAAs) are one of the disinfection by-product (DBPs) compound found in treated drinking water. During disinfection, DBPs were generated when chlorine reacts with natural organic matter (NOM). This study determine the type of HAAs compounds found in the tap water, the concentration of these compound and the potential health risk on human exposed to HAAs in household tap water. The data for HAAs and other physical and chemical parameters of water were collected between February to March 2015; from 3 districts in Perlis, namely Kangar, Kuala Perlis and Jejawi. The samples were collected from tap water. The method used to prepare the sample were EPA method 552.3. The HAAs concentrations were determined by gas chromatography with mass spectroscopy (GC-MS). Trichloroacetic acid (TCAA) and dichloroacetic acids (DCAA) are 2 compounds that are most detected in treated drinking water. The range concentration of trichloroacetic acid (TCAA) and dichloroacetic acids (DCAA) are 0.21 mg/L to 0.28 mg/L and 0.31 mg/L to 0.38 mg/L. The levels of concentration of HAAs in residential tap water are above the maximum contaminated levels specified by World Health Organization (WHO) standards. The maximum contaminant level of DCAA and TCAA according to WHO are 50 μg/L and 100 μg/L. The cancer risk value only available for DCAA only. The mean value for oral ingestion and inhalation are 4.69x10-4 and 4.38x10-13, respectively. The overall result of cancer risk obtained for HAAs were below than 10-4 as suggested by EPA standard. However, the result for non-cancer risk suggested that long term exposure to HAAs may resulted to high risk on human. The potential are cancer (liver, kidney & bladder), reproductive and development effects.