Environmental Radioactivity and High Incidence Rates of Stomach and Esophagus Cancer in the Van Lake Region: A Causal Relationship?

This study examined the incidence rates of cancer cases (averages for 2006-2010) and relationships withenvironmental radioactivity levels. Soil and water samples were collected from provincial and district centersof Van city and the outdoor gamma doses were determined using a portable gamma scintillation detector. Grossalpha and beta, (226)Ra, (232)Th, and (40)K activities were measured in both tap water and soil samples. Althoughhigh rates of stomach and esophagus cancers have been reported previously in Van the underlying reasons havenot hitherto been defined. Incidences of cancers were highest in the Gurpınar (326.0) and Ozalp (377.1) counties(p<0.001). As to the results of the gross alpha and gross beta radioactivity measurements in the drinking water,these two counties also had high beta radionuclide levels: Gurpınar (140 mBq/dm³) and Ozalp (206 mBq/dm³).Even if within the normal range, a relation between the higher rate of the incidence of stomach and esophaguscancers with that of the higher rate of beta radionuclide activity was clear. On Spearman correlation analysis,the relation between higher beta radionuclide levels and cancer incidence was found to be statistically significant(p<0.01). According to the results of the analysis, Van residents receive an average 1.86 mSv/y annual dose fromoutdoor gamma radiation, ingestion of radionuclides in the drinking water, and indoor 222Rn activity. Moreover,gross alpha and beta activities were found to be extremely high in all of the lakes around the city of Van, Turkey.Further investigations with long-term detailed environmental radiation measurements are needed regardingthe relationship between cancer cases and environmental radioactivity in the city of Van.