Tohoku J. Exp. Med., 2012, 226(1)

Association of Nitrogen Compounds in Drinking Water with Incidence of Esophageal Squamous Cell Carcinoma in Shexian, China

NAN ZHANG,¹ CAO YU,² DENGGUI WEN,² JUN CHEN,¹ YIWEI LING,¹ KENSHI TERAJIMA,¹ KOHEI AKAZAWA,¹ BAOEN SHAN² and SHIJIE WANG²

¹Department of Medical Informatics, Niigata University Medical and Dental Hospital, Niigata, Japan
²Fourth Affiliated Hospital of Hebei Medical University, Shijiazhuang, China

The incidence of esophageal squamous cell carcinoma (ESCC), which is the eighth most common malignancy worldwide, is highest in China. The purpose of this study was to investigate the association between nitrogen compounds in drinking water with the incidence of ESCC by geographical spatial analysis. The incidence of ESCC is high in Shexian county, China, and environmental factors, particularly nitrogen-contaminated drinking water, are the main suspected risk factors. This study focuses on three nitrogen compounds in drinking water, namely, nitrates, nitrites, and ammonia, all of which are derived mainly from domestic garbage and agricultural fertilizer. The study surveyed 48 villages in the Shexian area with a total population of 54,716 (661 adults with ESCC and 54,055 non-cancer subjects). Hot-spot analysis was used to identify spatial clusters with a high incidence of ESCC and a high concentration of nitrogen compounds. Logistic regression analysis was used to detect risk factors for ESCC incidence. Most areas with high concentrations of nitrate nitrogen in drinking water had a high incidence of ESCC. Correlation analysis revealed a significant positive relationship between nitrate concentration and ESCC (P = 0.01). Logistic regression analysis also confirmed that nitrate nitrogen has a significantly higher odds ratio. The results indicate that nitrate nitrogen is associated with ESCC incidence in Shexian county. In conclusion, high concentrations of nitrate nitrogen in drinking water may be a significant risk factor for the incidence of ESCC.

keywords —— esophageal squamous cell carcinoma; geographic information system; nitrate nitrogen; spatial analysis; water pollution

© 2012 Tohoku University Medical Press

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Tohoku J. Exp. Med., 2012, 226, 11-17

Correspondence: Nan Zhang, Department of Medical Informatics, Niigata University Medical and Dental Hospital, Asahimachi-Dori 1-754, Niigata 951-8520, Japan.

e-mail: zhangnan@med.niigata-u.ac.jp