title: Quality of drinking water and high incidence rate of esophageal cancer in Golestan province of Iran: a probable link.
abstract: Golestan province in north Iran is known to be a high-risk area for esophageal cancer (EC). Of a long list of multiple risk factors, this study focuses on a possible link between the epidemiologic patterns of EC and the anomalous concentration of some ions and elements in the drinking water sources. A total of 183 samples from 45 villages covering a wide range of EC mortality rates are collected and analyzed. The results demonstrate that NO(3)(-), SO(4)(2-), Sb, and Sr exceed the recommended maximum concentration level (MCL) in drinking water. This is more prominent in the villages with high esophageal cancer mortality rate, suggesting a possible link between EC incidence and water quality. Se concentration in drinking water increases from low to the high EC areas, a finding contrary to the expected trend. It is concluded that Se deficiency does not play a major role in the etiology of EC in the Golestan province. The statistical results obtained from Mann-Whitney and Kruskal-Wallis tests along with cluster analysis are consistent with the observed trend of EC mortality rate in Golestan province.
authors.affiliation: Department of Earth Sciences, College of Sciences, Shiraz University, 71454 Shiraz, Iran. bkeshavarzi@shirazu.ac.ir
authors.forename: Behnam
authors.initials: B
authors.lastname: Keshavarzi
authors.forename: Farid
authors.initials: F
authors.lastname: Moore
authors.forename: Ali
authors.initials: A
authors.lastname: Najmeddin
authors.forename: Farah
authors.initials: F
authors.lastname: Rahmani
authors.forename: Ahad
authors.initials: A
authors.lastname: Malekzadeh
mesh_terms: D016000:Cluster Analysis; D060766:Drinking Water / Q000032:analysis* / Q000737:chemistry; D004938:Esophageal Neoplasms / Q000453:epidemiology / Q000209:etiology*; D005260:Female; D006801:Humans; D015994:Incidence; D007492:Iran / Q000453:epidemiology; D008297:Male; D013058:Mass Spectrometry; D012307:Risk Factors; D018709:Statistics, Nonparametric; D060753:Water Quality
chemical_list: D060766:Drinking Water