Excretion Profiles and Half-Lives of Ten Urinary Polycyclic Aromatic Hydrocarbon Metabolites after Dietary Exposure

Abstract

Human exposure to polycyclic aromatic hydrocarbons (PAHs) can be assessed by biomonitoring of their urinary mono-hydroxylated metabolites (OH-PAHs). Limited information exists on the human pharmacokinetics of OH-PAHs. This study aimed to investigate the excretion half-life of 1-hydroxypyrene (1-PYR), the most used biomarker for PAH exposure, and 9 other OH-PAHs following a dietary exposure in 9 non-smoking volunteers with no occupational exposure to PAHs. Each person avoided food with known high PAH-content during the study period, except for a high PAH-containing lunch (barbecued chicken) on the first day. Individual urine samples (n = 217) were collected from 15 hours before to 60 hours following the dietary exposure. Levels of all OH-PAHs in all subjects increased rapidly by 9-141 fold after the exposure, followed by a decrease consistent with first order kinetics, and returned to background levels 24-48 hours after the exposure. The average time to reach maximal concentration ranged from 3.1 h (1-naphthol) to 5.5 h (1-PYR). Creatinine-adjusted urine concentrations for each metabolite were analyzed using a non-linear mixed effects model including a term to estimate background exposure. The background-adjusted half-life estimate was 3.9 h for 1-PYR and ranged 2.5-6.1 h for the other 9 OH-PAHs, which in general, were shorter than those previously reported. The maximum concentrations after the barbecued chicken consumption were comparable to the levels found in reported occupational settings with known high PAH exposures. It is essential to consider the relatively short half-life, the timing of samples relative to exposures, and the effect of diet when conducting PAH exposure biomonitoring studies.

Urinary polycyclic aromatic hydrocarbon metabolites as biomarkers to woodsmoke exposure — results from a controlled exposure study

“…The data for each OH-PAH were combined from all participants and analyzed using a non-linear mixed effects model 34 to calculate the mean background level, mean uptake level, mean decay rate parameter and the population median half-life ( t 1/2 ). The model took into account background exposure, first order decline of metabolites following exposure, and between-subject variation in pharmacokinetics.…”

Repeatedly high polycyclic aromatic hydrocarbon exposure and cockroach sensitization among inner-city children

“…Of the 258 children with age 9–10 urinary sample, 248 children had age 5 urinary samples (Fig.1). The urinary concentrations of 10 PAH metabolites were measured at CDC using a method described in detail previously (Li et al 2014). In brief, urine samples (1 mL) were first spiked with 13 C-labeled internal standards, subjected to overnight enzymatic deconjugation, and followed by semi-automated liquid-liquid extraction.…”

“…All OH-PAH analyses were subjected to a series of quality control and quality assurance checks as described elsewhere (Li et al, 2014). Two quality control materials (QCs)—QC High and QC Low—were prepared by spiking standard mixture into anonymous urine pools, and were analyzed along with each run of the urine samples.…”

Urinary metabolites of polycyclic aromatic hydrocarbons in Saudi Arabian schoolchildren in relation to sources of exposure

“…It has the advantages of strong correlation with metabolites of other PAH (Li et al 2008) and of having a relatively short biological half life, and hence being representative of recent exposure. Half-lives from inhalation exposure are reported as between 6 and 35 h (Brzeznicki et al 1997;Jongeneelen et al 1990), 4.4 h and 12 h after oral ingestion (Buckley and Lioy, 1992;Viau et al 1995) and 3.5-5.1 h for the first phase (Li et al, 2012). Hansen et al (2008) have reviewed 132 studies addressing the use of 1-hydroxypyrene as a biomarker of both occupational and environmental exposure to PAH.…”