High exposure to polycyclic aromatic hydrocarbons may contribute to high risk of esophageal cancer in northeastern Iran.
BACKGROUND
The northeastern region of Iran has some of the highest rates of esophageal squamous cell carcinoma (ESCC) in the world.


METHODS
To investigate the role of polycyclic aromatic hydrocarbons (PAHs) in the etiology of ESCC in northeastern Iran, we measured urine 1-hydroxypyrene glucuronide (1-OHPG), a stable PAH metabolite, in 99 inhabitants of this area.


RESULTS
The median urine 1-OHPG in participants of this study was 4.2 pmol/ml. Forty-two subjects (42%) had levels ranging from 1 to 5 pmol/ml, indicative of moderate PAH exposure, and 41 (41%) had levels above 5 pmol/ml, indicative of very high exposure. Further analysis showed that 1-OHPG levels were high in all subgroups of our study subjects, including both sexes, rural and urban dwellers, and smokers and non-smokers. Only 15% of the variance in 1-OHPG was explained by age, sex, residence, smoking, nass, or opium consumption. This pattern of PAH exposure parallels the ESCC incidence pattern seen in this area.


CONCLUSIONS
We conclude that people in northeastern Iran are exposed to widespread and very high levels of PAH, largely from unknown sources, and this may contribute to the high rates of ESCC observed in this area.
Kamangar
Farin
F
Cancer Prevention Studies Branch, Center for Cancer Research, National Cancer Institute, Bethesda, MD 21218, USA. kamangaf@mail.nih.gov
Strickland
Paul T
PT
Pourshams
Akram
A
Malekzadeh
Reza
R
Boffetta
Paolo
P
Roth
Mark J
MJ
Abnet
Christian C
CC
Saadatian-Elahi
Mitra
M
Rakhshani
Nasser
N
Brennan
Paul
P
Etemadi
Arash
A
Dawsey
Sanford M
SM
D000328:Adult; D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000139:chemically induced* / Q000209:etiology*; D004781:Environmental Exposure; D004938:Esophageal Neoplasms / Q000139:chemically induced* / Q000209:etiology*; D005260:Female; D005965:Glucuronates / Q000652:urine; D006801:Humans; D007492:Iran; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D011084:Polycyclic Aromatic Hydrocarbons / Q000009:adverse effects*; D011721:Pyrenes; D012306:Risk
C093851:1-hydroxypyrene-glucuronide; D005965:Glucuronates; D011084:Polycyclic Aromatic Hydrocarbons; D011721:Pyrenes