Trihalomethanes and associated potential cancer risks in the water supply in Ankara, Turkey.
ABSTRACT The occurrence of trihalomethanes (THMs) in the water supply in the Ankara, Turkey was investigated. Total THMs and total organic carbon measurements were carried seasonally in the samples collected form 22 different districts along with the samples taken from the Ivedik Water Treatment Plant serving 90% of the city. The average summer nonpurgeable organic carbon (NPOC) concentration in the raw water was 4.2 mg/L, and the NPOC removal achieved in the treatment plant was 31%. The concentration of total THMs ranged from 25 to 74 microg/L, from 28 to 73 microg/L, and from 25 to 110 microg/L in winter, spring, and summer, respectively. In all of the samples chloroform existed at the highest concentrations, while bromoform was almost absent. The total THM concentrations were highest in summer for all districts. However, none of the concentrations detected exceeded the USEPA's Stage I limit of 80 microg/L and the EU's limit of 100 microg/L. However, the total THM level in 64% of the districts exceeded the USEPA's Stage II limit of 40 microg/L. The risk estimations carried out indicated that each year 1 of the 5 million Ankara residents could get cancer from the daily intake of water, mainly because of exposure to chloroform through oral ingestion.
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ABSTRACT: A total of 29 surface waters from different regions of Turkey were sampled once a month during 2004. Filtered raw water samples were characterized, chlorinated and the concentrations of disinfection by-products (DBPs) were measured. All waters were low in DOC ranging from 0.91 to 4.42 mg/L. The range of annual average trihalomethanes (THMs) and haloacetic acids (HAAs) concentrations in all waters was 21-189 and 18-149mug/L, respectively. Total mass contributions of halides in THMs and HAAs to absorbable organic halides (AOX) ranged between 10 and 56% in all waters on annual average basis, indicating that significant amounts of other DBPs are being formed in the majority of the tested waters. A strong linear correlation was obtained between the concentrations of THMs and HAAs. Rather poor correlations were found for THMs-AOX and HAAs-AOX levels. For both THMs and HAAs, chlorinated species dominated over brominated ones since the majority of water sources had very low bromide levels. While chloroform and trichloroacetic acid were the major THM and HAA compounds, respectively; the extent of formation and speciation of DBPs varied greatly by season and water source. No consistent general trends were observed in terms of seasonal variations in DBP levels, suggesting that the characteristics of NOM moieties and their chlorine reactivity vary by season in almost all waters tested.Journal of Hazardous Materials 05/2007; 142(1-2):526-34. · 4.17 Impact Factor