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

Abstract

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.

Procarcinogen Activation and Mutational Signatures Model the Initiation of Carcinogenesis in Human Urothelial Tissues In Vitro

“…Our study supports a role for BaP in bladder carcinogenesis. BaP is a polycyclic aromatic hydrocarbon (PAH) procarcinogen found in cigarette smoke and detectable in the urine of smokers or healthy volunteers after a PAH-rich meal [8] . Cigarette smoking is the main risk factor for BLCA (estimated hazard ratio is 2–4 for current smokers [9] ).…”

A Review of the Impact of Selected Anthropogenic Chemicals from the Group of Endocrine Disruptors on Human Health

“…Epidemiological tests have concluded that PAHs have cancerogenic activity, e.g., contributing to lung cancer, as well as genotoxic and mutagenic activity, while BaP is a major promotor of pancreatic cancer and colorectal adenoma. Due to its affinity for fat, BaP is also detected in female milk, which puts babies at risk from the first days of their lives [ 1 , 38 , 60 , 61 ]. This is particularly important because of the influence of these chemicals on human reproductive activities.…”

“…Their presence in the human organism can lead to male infertility due to competition for aryl hydrocarbon receptors (AhRs) [ 1 , 62 ]. In women, it leads to malfunction of the ovaries, which may result in premature menopause [ 61 , 63 ]. Detailed information is provided in Table 6 .…”

Analytical chemistry, formation, mitigation, and risk assessment of polycyclic aromatic hydrocarbons: From food processing to in vivo metabolic transformation

“…The urinary concentrations of BaP-r-7,t-8,t-9,c-10-tetrahydrotetrol (BPT I-1) and BaP-r-7,t-8,c-9,c-10-tetrahydrotetrol were measured in smokers and nonsmokers and results showed that the median concentration of BPT I-1 in smokers' urine (0.069 pg/mL) was significantly higher than that in nonsmokers (0.043 pg/mL). Therefore, the authors suggested that the application of BPT I-1 as a biomarker warranted further investigation (Hilton, Trinidad, Hubbard, Li, & Sjödin, 2017). In addition to metabolites, parent PAHs have also been used as biomarkers to estimate PAH exposure.…”