Abstracts: ISEE 22nd Annual Conference, Seoul, Korea, 28 August-1 September 2010: Exposure Assessment by Various Media and Pathways
Drinking water chlorination treatments produce different disinfection by-products (DBPs) as a consequence of the reaction between chlorine in water and natural organic matter. This study is part of the international project HiWATE (Health Impacts of Long-Term Exposure to Disinfection By-Products in Drinking Water) supported by the EU Sixth Framework programme (FP6). The aim was to investigate the presence of DBPs in drinking water in different northern regions in Italy, where groundwater with low organic matter is generally supplied and where the use of chlorine dioxide as chlorination treatment is widespread.
Bromate, chlorite, chlorate, haloacetic acids and 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone (MX) and trihalomethanes levels were investigated in drinking water samples collected form 12 waterworks located in Emilia Romagna, Friuli Venezia Giulia, and Lombardia Regions. To investigate seasonal variability, water samples were collected for 4 seasons between 2007 and 2008.
MX and haloacetic acids were never detected (detection limit: 0.5 ng/L and 1 μg/L, respectively). Trihalomethanes were always found at very low concentrations regardless of the disinfection treatment (mean: 2.04 μg/L, maximum value: 26.9 μg/L). Bromate was detected only in one waterworks in which disinfection was performed by ozone and chloride dioxide (range: 2–14 μg/L). Chlorite was found only in chlorine dioxide-disinfected drinking water (4 waterworks; mean value: 136 μg/L; range:28–523 μg/L), whereas chlorate resulted the most widespread DBP (>85% of the samples), with concentrations ranging from 1 to 399 μg/L. No consistent general trends were observed, for DBPs seasonal variations, in the investigated Italian drinking waters.
DBPs levels in Italian drinking water appear generally low; however, individual DBPs and levels vary according to the different disinfection treatments: when chlorine dioxide is applied as disinfection method, high values of chlorite and chlorate could have been detected. Because of their potential health effects, the presence of chlorite and chlorate in drinking water deserve further investigation.