Dietary Intake of Benzo(α)pyrene and Risk of Esophageal Cancer in Iran

Abstract

Background: Residents of the northeastern region of Iran experience high mortality rates from esophageal squamous cell carcinoma (ESCC). One etiologic factor might be exposure to high levels of polycyclic aromatic hydrocarbons, including benzo(|α|)pyrene (BαP). We examined whether food or water are the major sources of BαP exposure in this population.

Materials and Methods: We used a dietary questionnaire to assess the daily intake of staple foods (rice and bread) and water in three groups: 40 ESCC cases living in the high-risk area of northeastern Iran, 40 controls from the same area, and 40 controls from low-risk area of southern Iran. We then measured, by high-performance liquid chromatography combined with fluorescence detection (HPLC-FL), the BαP concentration of bread, rice, water in 90 samples obtained from these three groups, and derived the daily intake of BαP by multiplying daily food or water intake by their BαP concentration.

Results: Mean BαP concentration of staple foods and water was similar and within standard levels in both areas, but the daily intake of BαP was higher in controls from the high-risk area than in controls from the low-risk one (91.4 vs. 70.6 ng/day, p‹0.01), and remained significant after adjusting for living place (urban, rural) and indoor PAH sources including smoking, opium, heating and cooking fuel.

Conclusion: Although B‹P levels in staple food and water were not highly elevated, people who lived in the high-risk area may be more exposed to carcinogenic polycyclic aromatic hydrocarbons through their diet.