Urinary hydroxylated metabolites of polycyclic aromatic hydrocarbons as biomarkers of exposure in asphalt workers.
BACKGROUND
Fumes and vapours released during laying of hot asphalt mix have been recognised as a major source of exposure for asphalt workers.


OBJECTIVE
We investigated the relationships between inhalation exposure to asphalt emissions and urinary biomarkers of polycyclic aromatic hydrocarbons (PAHs) in asphalt workers (AW, n=75) and in ground construction workers (CW, n=37).


METHODS
Total polyaromatic compounds (PAC) and 15 priority PAHs in inhaled air were measured by personal sampling. Hydroxylated PAH metabolites (OH-PAHs) (2-naphthol, 2-hydroxyfluorene, 3-hydroxyphenanthrene, 1-hydroxypyrene, 6-hydroxychrysene and 3-hydroxybenzo[a]pyrene) were determined in urine spot samples collected in three different times during the work week.


RESULTS
Median vapour-phase PAC (5.5 microg m(-3)), PAHs (<or=50 ng m(-3)) and OH-PAHs (0.08-1.11 microg l(-1)) were significantly higher in AW than in CW, except in the cases of air naphthalene and 2-naphthol. Airborne levels of particle-phase contaminants were similar in the two groups and much lower than vapour-phase levels; metabolites of particulate PAHs were never found in quantifiable amounts. An appreciable increase in OH-PAH levels during the work day and work week was found in AW; median levels for 2-hydroxyfluorene, 3-hydroxyphenanthrene and 1-hydroxypyrene were, respectively, 0.29, 0.08 and 0.18 at baseline; 0.50, 0.18 and 0.29, pre-shift; 1.11, 0.44 and 0.44 microg l(-1), post-shift. Each OH-PAH exhibited a characteristic profile of increase, reflecting differences in half-lives of the parent compounds. In non-smoking subjects, positive correlations were found between vapour-phase PAC or PAHs and OH-PAHs both in pre- and post-shift samples (0.34 <or= r<or=69). Smokers exhibited 2-5-fold higher OH-PAHs than non-smokers, at any time and at both workplaces.


CONCLUSIONS
Our results suggest that OH-PAHs are useful biomarkers for monitoring exposure to asphalt emissions. The work-related exposure to PAC and PAHs was low in all AW, but urinary metabolites reflected exposure satisfactorily.
Buratti
M
M
Department of Occupational and Environmental Health, University of Milan and Fondazione IRCCS Ospedale Maggiore Policlinico, Mangiagalli e Regina Elena, Via S. Barnaba, Milan, Italy.
Campo
L
L
Fustinoni
S
S
Cirla
P E
PE
Martinotti
I
I
Cavallo
D
D
Foa
V
V
D000328:Adult; D000368:Aged; D000388:Air / Q000032:analysis; D000395:Air Pollutants, Occupational / Q000032:analysis*; D001580:Benzopyrenes / Q000032:analysis; D015415:Biomarkers / Q000652:urine*; D002911:Chrysenes / Q000652:urine; D004784:Environmental Monitoring / Q000379:methods; D005449:Fluorenes / Q000652:urine; D006801:Humans; D006838:Hydrocarbons; D006900:Hydroxylation; D019570:Inhalation Exposure; D007558:Italy; D008297:Male; D008875:Middle Aged; D009284:Naphthols / Q000652:urine; D016273:Occupational Exposure / Q000032:analysis*; D010616:Phenanthrenes / Q000652:urine; D011084:Polycyclic Aromatic Hydrocarbons / Q000378:metabolism / Q000652:urine*; D011721:Pyrenes / Q000032:analysis; D012907:Smoking / Q000652:urine
D000395:Air Pollutants, Occupational; D001580:Benzopyrenes; D015415:Biomarkers; D002911:Chrysenes; D005449:Fluorenes; D006838:Hydrocarbons; D009284:Naphthols; D010616:Phenanthrenes; D011084:Polycyclic Aromatic Hydrocarbons; D011721:Pyrenes; C087203:6-hydroxychrysene; C021338:3-hydroxybenzo(a)pyrene; C006647:asphalt; C477779:2-hydroxyfluorene; C033146:1-hydroxypyrene; C028405:2-naphthol