Exposure to Polycyclic Aromatic Hydrocarbons Among Never Smokers in Golestan Province, Iran, an Area of High Incidence of Esophageal Cancer – a Cross-Sectional Study with Repeated Measurement of Urinary 1-OHPG in Two Seasons

Abstract

Studies have suggested a possible role of polycyclic aromatic hydrocarbons (PAHs) in the etiology of esophageal cancer in Golestan Province, Iran, where incidence of this cancer is very high. In order to investigate the patterns of non-smoking related exposure to PAHs in Golestan, we conducted a cross-sectional study collecting questionnaire data, genotyping polymorphisms related to PAH metabolism, and measuring levels of 1-hydroxypyrene glucuronide (1-OHPG), a PAH metabolite, in urine samples collected in two seasons from the same group of 111 randomly selected never-smoking women. Beta-coefficients for correlations between 1-OHPG as dependent variable and other variables were calculated using linear regression models. The creatinine-adjusted 1-OHPG levels in both winter and summer samples were approximately 110 μmol/molCr (P for seasonal difference = 0.40). In winter, red meat intake (β = 0.208; P = 0.03), processed meat intake (β = 0.218; P = 0.02), and GSTT1-02 polymorphism (“null” genotype: β = 0.228; P = 0.02) showed associations with 1-OHPG levels, while CYP1B1-07 polymorphism (GG versus AA + GA genotypes: β = –0.256; P = 0.008) showed an inverse association. In summer, making bread at home (> weekly versus never: β = 0.203; P = 0.04), second-hand smoke (exposure to ≥3 cigarettes versus no exposure: β = 0.254; P = 0.01), and GSTM1-02 “null” genotype (β = 0.198; P = 0.04) showed associations with 1-OHPG levels, but GSTP1-02 polymorphism (CT + TT versus CC: β = –0.218; P = 0.03) showed an inverse association. This study confirms high exposure of the general population in Golestan to PAHs and suggests that certain foods, cooking methods, and genetic polymorphisms increase exposure to PAHs.

Food preparation methods, drinking water source, and esophageal squamous cell carcinoma in the high-risk area of Golestan, Northeast Iran

“…Elevated levels of carcinogenic PAH in the kitchen air and meat following frying meat have been reported elsewhere (14). A positive association between red meat intake and urinary 1-OHPG has also been reported in high-risk areas of Golestan (41). …”

Dietary food groups intake and cooking methods associations with pancreatic cancer: A case–control study

“…PAH is a carcinogen type A which is mostly associated with smoking and cooking methods such as barbecuing and grilling [19][20][21][22][23][24]. A recent case-control study reported an increased risk of PC associated with high intakes of various HCAs [25].…”

Environmental risk factors for oesophageal cancer in Malawi: A case-control study

“…Specifically, wood-burning with subsequent release of polycyclic aromatic hydrocarbons (PAH) has been shown to be a risk factor in other settings. [11][12][13] On mycotoxins, our hypothesis was that m'gaiwa (whole grain maize flour), being the least processed type of local maize flour, harbours the most fumonisins and aflatoxins compared to other types of maize flour. Fumonisins and aflatoxins are types of mycotoxins produced by Fusarium and Aspergillus species of fungi, respectively, and have been associated with oesophageal cancer in other studies in the region, 8,[14][15] and in Iran.…”