Drinking water and esophageal cancer in northern Iran

ABSTRACT

Fifty-one out of one-thousand stations were selected in Northern Iran for evaluating the genotoxicity of daily consumed drinking water. This part of Iran has one of the highest prevalences of esophageal cancer in the world. Water sampling was carried out from river, stored rain water, spring, canal, deep and shallow wells. Extracts prepared from river and stored-rain waters induced high mutagenicity in Salmonella typhimurium TA98 strain, while the TA100 strain did not show any response. Spring and canal water extracts caused a significant increase in the TA98 his+ revertants which was not observed in TA100. Among the 40 sampled deep and shallow well water concentrates, only 1/3 of the latter induced significant mutagenicity in the TA98 strain, 2/3 of extracts of both sources showed no sign of mutagenicity in TA100, while the remaining 1/3 caused various levels of lethalities in this strain. No lethalities were detected in this strain when river and stored rain water extracts were tested. Among all of the prepared extracts, only those belonging to river and stored rain water caused remarkable induction of DNA breaks in V79 fibroblasts