Annals of Occupational Hygiene Advance Access originally published online on December 12, 2005
Annals of Occupational Hygiene 2006 50(3):211-218; doi:10.1093/annhyg/mei072
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© 2005 British Occupational Hygiene Society Published by Oxford University Press
Original Article |
Sister Chromatid Exchange and Oxidative DNA Damage in Paving Workers exposed to PAHs
1 Department of Occupational Medicine, ISPESL Monteporzio Catone, Rome, Italy; 2 Laboratory of Public health, ASL-Florence, Italy; 3 Department of Prevention ASL RMG, Guidonia, Rome, Italy
* Author to whom correspondence should addressed. Tel: +39-6-94181409; fax: +39-6-94181410; e-mail: cavallo.d{at}tiscali.it
Paving workers are exposed during road paving to several polycyclic aromatic hydrocarbons (PAHs) contained in asphalt fumes. In this study early genotoxic and oxidative effects of exposure to bitumen fumes were evaluated in 19 paving workers and 22 controls. Environmental and biological monitoring of exposure was carried out, measuring, on personal air samples from exposed workers collected during three working days, the concentration of 14 PAHs and urinary OH-pyrene at the end of each of the three working days. Genotoxic effect was evaluated analysing sister chromatid exchange (SCE) frequency and direct-oxidative DNA damage by formamido–pyrimidine–glycosylase (Fpg)-modified comet assay on lymphocytes. Tail moment values from Fpg-enzyme treated cells (TMenz) and from untreated cells (TM) were used as parameters of direct and oxidative DNA damage, respectively. For each subject, the TMenz/TM ratio >2.0 was used to indicate the presence of oxidative damage. DNA damage was also evaluated analysing comet percentage. Personal air samples showed low level of total PAHs (2.843 µg m–3) with prevalence of 2–3 ring PAHs (2.693 µg m–3). Urinary OH-pyrene after work-shift of the three working days was significantly higher than that found at the beginning of the working week. SCE analysis did not show any difference between two groups while an oxidative DNA damage was found in 37% of exposed with respect to the absence in controls. Comet percentage was significantly higher (P = 0.000 ANOVA) in the exposed than in controls. The results demonstrate the high sensitivity of comet assay to assess early oxidative effects induced by exposure to bitumen fumes at low doses and confirm the suitability of urinary OH-pyrene as a biomarker of PAH exposure. In conclusion the study suggests the use of Fpg-modified comet test as a biomarker of early genotoxic effects and that of urinary OH-pyrene as a biomarker of PAH exposure to furnish indications in terms of characterization, prevention and management of risk in occupational exposure to mixtures of potentially carcinogenic substances.
Keywords: genotoxic effects • paving workers • polycyclic aromatic hydrocarbons • urinary 1-OH pyrene