ORIGINAL ARTICLES

Urinary naphthalene and phenanthrene as biomarkers of occupational exposure to polycyclic aromatic hydrocarbons

J R Sobus¹, S Waidyanatha¹, M D McClean², R F Herrick², T J Smith², E Garshick^3,4, F Laden^2,4, J E Hart^2,4, Y Zheng⁵, S M Rappaport⁶

¹ School of Public Health, University of North Carolina, Chapel Hill, North Carolina, USA
² Exposure, Epidemiology and Risk Program, Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts, USA
³ Pulmonary and Critical Care Medicine Section, Medical Service, VA Boston Healthcare System, Boston, Massachusetts, USA
⁴ Channing Laboratory, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, USA
⁵ National Institute for Occupational Health and Poison Control, Chinese Center for Disease Control and Prevention, Beijing, China
⁶ School of Public Health, University of California, Berkeley, California, USA

Professor S M Rappaport, School of Public Health, University of California, Berkeley, California 94720-7356, USA; srappaport{at}berkeley.edu

Objectives: The study investigated the utility of unmetabolised naphthalene (Nap) and phenanthrene (Phe) in urine as surrogates for exposures to mixtures of polycyclic aromatic hydrocarbons (PAHs).

Methods: The report included workers exposed to diesel exhausts (low PAH exposure level, n = 39) as well as those exposed to emissions from asphalt (medium PAH exposure level, n = 26) and coke ovens (high PAH exposure level, n = 28). Levels of Nap and Phe were measured in urine from each subject using head space-solid phase microextraction and gas chromatography-mass spectrometry. Published levels of airborne Nap, Phe and other PAHs in the coke-producing and aluminium industries were also investigated.

Results: In post-shift urine, the highest estimated geometric mean concentrations of Nap and Phe were observed in coke-oven workers (Nap: 2490 ng/l; Phe: 975 ng/l), followed by asphalt workers (Nap: 71.5 ng/l; Phe: 54.3 ng/l), and by diesel-exposed workers (Nap: 17.7 ng/l; Phe: 3.60 ng/l). After subtracting logged background levels of Nap and Phe from the logged post-shift levels of these PAHs in urine, the resulting values (referred to as ln(adjNap) and ln(adjPhe), respectively) were significantly correlated in each group of workers (0.71 Pearson r0.89), suggesting a common exposure source in each case. Surprisingly, multiple linear regression analysis of ln(adjNap) on ln(adjPhe) showed no significant effect of the source of exposure (coke ovens, asphalt and diesel exhaust) and further suggested that the ratio of urinary Nap/Phe (in natural scale) decreased with increasing exposure levels. These results were corroborated with published data for airborne Nap and Phe in the coke-producing and aluminium industries. The published air measurements also indicated that Nap and Phe levels were proportional to the levels of all combined PAHs in those industries.

Conclusion: Levels of Nap and Phe in urine reflect airborne exposures to these compounds and are promising surrogates for occupational exposures to PAH mixtures.

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

• Sobus, J. R., Mcclean, M. D., Herrick, R. F., Waidyanatha, S., Onyemauwa, F., Kupper, L. L., Rappaport, S. M. (2009). Investigation of PAH Biomarkers in the Urine of Workers Exposed to Hot Asphalt. ANN OCCUP HYG 53: 551-560 [Abstract] [Full Text]  
• Sobus, J. R., McClean, M. D., Herrick, R. F., Waidyanatha, S., Nylander-French, L. A., Kupper, L. L., Rappaport, S. M. (2009). Comparing Urinary Biomarkers of Airborne and Dermal Exposure to Polycyclic Aromatic Compounds in Asphalt-Exposed Workers. ANN OCCUP HYG 53: 561-571 [Abstract] [Full Text]