Selenium levels in rice samples from high and low risk areas for esophageal cancer

ABSTRACT

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. 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. 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]. 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