Abstract

Objectives: To assess the relationship between selenium (Se) concentration in rice and the incidence of esophageal cancer (EC) in a high risk area in Northern Iran. Methods: This ecological study was conducted in Golestan province of Iran in 2012. In this area, 45714 acres of land are cultivated by rice. A total of 69 rice samples were taken. We investigated Se concentrations by the voltammetric method. Statistical analysis was performed using the Pearson correlation test and Mann-Whitney U test. Results: The mean (+/- SD) Se level in rice samples was 0.229 (+/- 0.145) mg/kg. The Se concentration was significantly higher in rice samples from high EC rate areas (0.35 mg/kg) compared with low risk areas (0.16 mg/kg) (p<0.001). There was a significant positive correlation between the levels of Se in rice and the incidence rate of EC (p=0.03). Conclusion: We found a high rice Se concentration and a significant positive relationship between rice Se levels and EC rates in the Golestan province of Iran. High soil and rice Se levels may play a possible role in the pathogenesis of EC in this area.