Use of physiologically-based pharmacokinetic modeling to simulate the profiles of 3-hydroxybenzo(a)pyrene in workers exposed to polycyclic aromatic hydrocarbons.

Biomathematical modeling has become an important tool to assess xenobiotic exposure in humans. In the present study, we have used a human physiologically-based pharmacokinetic (PBPK) model and an simple compartmental toxicokinetic model of benzo(a)pyrene (BaP) kinetics and its 3-hydroxybenzo(a)pyrene (3-OHBaP) metabolite to reproduce the time-course of this biomarker of exposure in the urine of industrially exposed workers and in turn predict the most plausible exposure scenarios. The models were constructed from in vivo experimental data in rats and then extrapolated from animals to humans after assessing and adjusting the most sensitive model parameters as well as species specific physiological parameters.

3-Hydroxybenzo(a)pyrene as a biomarker of dermal exposure to benzo(a)pyrene.

The aim of this study was to determine the percutaneous absorption flux of BaP (20 microg/cm(2) in ethanol) and the usefulness of urinary 3-OHBaP as a bio-indicator of dermal exposure to BaP. The percutaneous absorbed dose and absorption flux were estimated by comparison with intravenous administration of BaP (0.01 and 0.

In vivo and in vitro percutaneous absorption of [14C]pyrene in Sprague Dawley male rats: skin reservoir effect and consequence on urinary 1-OH pyrene excretion.

The skin reservoir effect of [14C]pyrene (in vivo and in vitro) on percutaneous absorption was determined in male Sprague Dawley rats. The urinary 1-OHpyrene (1-OHPy) excretion was compared between dermal exposure and intravenous administration. In vivo, the percutaneous absorption flux of [14C]pyrene (200 microg/cm(2); 50 microL/cm(2) of ethanol) determined by sacrificing batches of rats after different exposure times over 4.

Effects of type of smoking (pipe, cigars or cigarettes) on biological indices of tobacco exposure and toxicity.

Although all forms of smoking are harmful, smoking pipes or cigars is associated with lower exposure to the lethal products of tobacco products and lower levels of morbidity and mortality than smoking cigarettes. Cytochrome P-450-1A (CYP1A) is a major pathway activating carcinogens from tobacco smoke. Our primary aim was to compare CYP1A2 activity in individuals smoking pipes or cigars only, cigarettes only and in non-smokers.

Detection of 1-hydroxypyrene in urine by direct fluorometric analysis on a solid sorbing phase. Validation and application of the method to biological monitoring of PAH-exposed persons.

A new method for the detection and quantification of 1-hydroxypyrene (1-OHPy) in the urines of persons exposed to polycyclic aromatic hydrocarbons (PAH) has been evaluated. The method is based on extraction/concentration of the analyte onto a small element cut into tabs from an extraction disk (ENVI-Disk trade mark C18 from Supelco) combined with front-face synchronous fluorescence detection and direct quantification on the solid sorbent element. The limit of detection for 1-OHPy was estimated to be about 0.