Urinary 1-hydroxypyrene and mutagenicity in bus drivers and mail carriers exposed to urban air pollution in Denmark.
BACKGROUND
Previous studies in Denmark have shown that bus drivers and tramway employees were at an increased risk for developing several types of cancer and that bus drives from central Copenhagen have high levels of biomarkers of DNA damage.


OBJECTIVE
The present study evaluates 1-hydroxypyrene concentrations and mutagenic activity in urine as biomarkers of exposure in non-smoking bus drivers in city and rural areas on a work day and a day off and in non-smoking mail carriers working outdoors (in the streets) and indoors (in the office).


METHODS
Twenty-four hour urine samples were collected on a working day and a day off from 60 non-smoking bus drivers in city and rural areas and from 88 non-smoking mail carriers working outdoors (in the streets) and indoors (in the office). The concentration of 1-hydroxypyrene was measured by means of HPLC and the mutagenic activity was assessed by the Ames assay with Salmonella tester strain YG1021 and S9 mix. The N-acetyltransferase (NAT2) phenotype was used as a biomarker for susceptibility to mutagenic/carcinogenic compounds.


RESULTS
Bus drivers excreted more 1-hydroxypyrene in urine than did mail carriers. The differences were slightly smaller when NAT2 phenotype, cooking at home, exposure to vehicle exhaust, and performing physical exercise after work were included. The NAT2 slow acetylators had 29% (1.29 [CI: 1.15-1.98]) higher 1-hydroxypyrene concentrations in urine than the fast acetylators. Male bus drivers had 0.92 revertants/mol creatinine [CI: 0.37-1.47] and female bus drivers 1.90 revertants/mol creatinine [CI: 1.01-2.79] higher mutagenic activity in urine than mail carriers.


CONCLUSIONS
The present study indicates that bus drivers are more exposed to polycyclic aromatic hydrocarbons (PAH) and mutagens than mail carriers. Mail carriers who worked outdoors had higher urinary concentration of 1-hydroxypyrene, a marker of exposure to PAH, than those working indoors. The individual levels of urinary mutagenic activity were not correlated to excretion of 1-hydroxypyrene. This might be due to the fact that the most potent mutagenic compounds in diesel exhaust are not PAH but dinitro-pyrenes. Among bus drivers, fast NAT2 acetylators had higher mutagenic activity in urine than slow NAT2 acetylators and female bus drivers had higher mutagenic activity than male bus drivers.
Hansen
Ase Marie
AM
Department of Physiology, National Institute of Occupational Health, Lersø Parkallé 105, DK-2100 Copenhagen Ø, Denmark. aamh@ami.dk
Wallin
Håkan
H
Binderup
Mona Lise
ML
Dybdahl
Marianne
M
Autrup
Herman
H
Loft
Steffen
S
Knudsen
Lisbeth Ehlert
LE
D000328:Adult; D000397:Air Pollution / Q000009:adverse effects*; D001191:Arylamine N-Acetyltransferase / Q000235:genetics; D001334:Automobile Driving; D015415:Biomarkers; D004784:Environmental Monitoring; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009153:Mutagens / Q000032:analysis*; D016273:Occupational Exposure; D011084:Polycyclic Aromatic Hydrocarbons / Q000633:toxicity; D011177:Postal Service; D011721:Pyrenes / Q000032:analysis*; D012737:Sex Factors; D014504:Urban Health
D015415:Biomarkers; D009153:Mutagens; D011084:Polycyclic Aromatic Hydrocarbons; D011721:Pyrenes; D001191:Arylamine N-Acetyltransferase; C478900:NAT2 protein, human; C033146:1-hydroxypyrene