Measurement of urinary Benzo[a]pyrene tetrols and their relationship to other polycyclic aromatic hydrocarbon metabolites and cotinine in humans

• Published in: Chemosphere (Oxford) 2017-12, Vol.189, p.365-372
• Main Authors: Hilton, Donald C., Trinidad, Debra A., Hubbard, Kendra, Li, Zheng, Sjödin, Andreas
• Format: Article
• Language: English
• Subjects: 1-Hydroxypyrene; Benzo(a)pyrene - analysis; Benzo(a)pyrene - metabolism; Benzo[a]pyrene; Cotinine - analysis; Cotinine - urine; Environmental Exposure - analysis; Environmental Exposure - statistics & numerical data; Environmental Monitoring - methods; Gas Chromatography-Mass Spectrometry; Humans; Methylnaphthalene; PAH; Polycyclic aromatic hydrocarbons; Polycyclic Aromatic Hydrocarbons - analysis; Polycyclic Aromatic Hydrocarbons - urine; Pyrenes - urine; Tobacco smoke
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2017.09.077

Biomonitoring of exposure to polycyclic aromatic hydrocarbons (PAHs) typically uses measurement of metabolites of PAHs with four or less aromatic rings, such as 1-hydroxypyrene, even though interest may be in exposure to larger and carcinogenic PAHs, such as benzo[a]pyrene (B[a]P). An improved procedure for measuring two tetrol metabolites of B[a]P has been developed. Using 2 mL urine, the method includes enzymatic deconjugation of the tetrol conjugates, liquid-liquid extraction, activated carbon solid phase extraction (SPE) and Strata-X SPE, and gas chromatography–electron capture negative ionization–tandem mass spectrometric determination. Limits of detection were 0.026 pg/mL (benzo[a]pyrene-r-7,t-8,t-9,c-10-tetrahydrotetrol, BPT I-1) and 0.090 pg/mL (benzo[a]pyrene-r-7,t-8,c-9,c-10-tetrahydrotetrol, BPT II-1). We quantified BPT I-1 and BPT II-1 in urine from a volunteer who consumed one meal containing high levels of PAHs (barbequed chicken). We also measured urinary concentrations of BPT I-1 and BPT II-1 in smokers and nonsmokers, and compared these concentrations with those of monohydroxy PAHs (OH-PAHs) and cotinine. Urinary elimination of BPT I-1 and BPT II-1 as a function of time after dietary exposure was similar to that observed previously for OH-PAHs. While the median BPT I-1 concentration in smokers’ urine (0.069 pg/mL) significantly differs from nonsmokers (0.043 pg/mL), BPT I-1 is only weakly correlated with cotinine. The urinary concentration of BPT I-1 shows a weaker relationship to tobacco smoke than metabolites of smaller PAHs, suggesting that other routes of exposure such as for example dietary routes may be of larger quantitative importance. •Other B[a]P sources than tobacco smoke are significant among smokers and non-smokers.•Difference in urine level by smoking status is greater for PYE and smaller PAH metabolites than B[a]P.•Excretion profile for B[a]P and other PAH metabolites are similar after a dietary exposure.•Validated measurement method for B[a]P in urine is presented.