title: Repeated measurements for assessment of urinary 2-naphthol levels in individuals exposed to polycyclic aromatic hydrocarbons.
abstract: A repeated measurement cohort study was conducted to determine whether 2-napthol can be a suitable biomarker for evaluating the magnitude of exposure to PAHs from coke oven emissions. Time-course patterns of urinary 2-naphthol levels in coke-oven workers were examined. Also, the correlation between urinary 2-naphthol levels and PAHs from personal breathing zone samples was analyzed while examining and adjusting possible confounding factors, such as smoking alcohol consumption, and age of human subjects. A total of 8 spot urine samples were collected from each high-exposure group (topside-oven workers, n = 17) and low-exposure group (side-oven workers, n = 25) during the whole working cycle, which consists of six consecutive working days followed by 2 days off. Personal breathing zone samples were collected to quantify PAH intake. A questionnaire was distributed and collected from each worker for assessment of demographic parameters. Our results confirmed that the topside-oven area contained significantly higher PAH levels than the side-oven area. Urinary 2-naphthol levels correlated with the levels of PAH species, including pyrene, benzo[k]fluoranthene, benezo[g,h,i]pyrene, naphthalene, phenanthrene, anthracene, indeno[1,2,3-cd]pyrene, benzo[k]fluoranthene, and total PAHs. During the working cycle, urinary 2-naphthol levels remained stable at around 46-97 ng/mg creatinine during the working days and dramatically increased during the off days. After stratification of data based on smoking status, smokers had significantly higher urinary 2-naphthol levels than non-smokers, and 2-naphthol levels positively correlated with smoking status. Coke-oven emissions are a source of exposure to naphthalene. Also, smoking is a significant source of exposure to naphthalene and served as a confounder factor. Due to its abundance, positive association with total PAHs and certain carcinogenic PAH compounds, and slower elimination kinetics, urinary 2-naphthol may have the potential to serve as a biomarker for PAH exposure, when smoking status is carefully adjusted.
authors.affiliation: School of Community and Environmental Health, College of Health Sciences, Old Dominion University, Norfolk, Virginia, USA.
authors.forename: Hueiwang Anna
authors.initials: HA
authors.lastname: Jeng
authors.forename: Chih-Hung
authors.initials: CH
authors.lastname: Pan
authors.forename: Guo-Ping
authors.initials: GP
authors.lastname: Chang-Chien
authors.forename: Norou
authors.initials: N
authors.lastname: Diawara
authors.forename: Chiung-Yu
authors.initials: CY
authors.lastname: Peng
authors.forename: Ming-Tsang
authors.initials: MT
authors.lastname: Wu
mesh_terms: D000328:Adult; D000395:Air Pollutants, Occupational / Q000032:analysis / Q000652:urine*; D015415:Biomarkers / Q000652:urine; D015331:Cohort Studies; D003077:Coke; D015986:Confounding Factors, Epidemiologic; D019652:Extraction and Processing Industry; D006801:Humans; D008875:Middle Aged; D009284:Naphthols / Q000652:urine*; D016273:Occupational Exposure / Q000032:analysis*; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis / Q000652:urine*; D012907:Smoking; D013624:Taiwan; D013997:Time Factors
chemical_list: D000395:Air Pollutants, Occupational; D015415:Biomarkers; D003077:Coke; D009284:Naphthols; D011084:Polycyclic Aromatic Hydrocarbons; C028405:2-naphthol