[Correlation of the risk of gastric cancer in the province of Soria and the nitrate content of drinking water].

Diverse previous epidemiological studies have associated the risk of gastric cancer (CG) with the nitrate content of drinking water in certain high risk areas in Columbia and Denmark, but in other countries no relation has been found and the topic is still controversial. In the present study and analysis is made of the differential risk of gastric cancer in the province of Soria (Spain) in terms of mortality and incidence in each of the natural regions of this province, investigating an eventual correlation with the nitrate content of the drinking water. Although the maximum nitrate content found barely exceeded the maximum limits suggested by the WHO, these values have a statistically significant positive linear correlation with the adjusted mortality (p less than 0.01) and incidence rates of gastric cancer in men (p less than 0.05). The authors discuss the need for further investigation of the topic in Spain since the nitrate values encountered might not reflect the true magnitude of environmental nitrate exposure, or there could be other factors related to agricultural work in the grain-producing regions where the maximum rates of gastric cancer in men are recorded.