Assessment of non-occupational exposure to polycyclic aromatic hydrocarbons through personal air sampling and urinary biomonitoring

Abstract

Non-occupational inhalation and ingestion exposure to polycyclic aromatic hydrocarbons (PAHs) has been studied in 8 non-smoking volunteers through personal air sampling and urinary biomonitoring. The study period was divided into 4 segments (2 days/segment), including weekdays with regular commute and weekends with limited traffic related exposures; each segment had a high or low PAH diet. Personal air samples were collected continuously from the subjects while at home, at work, and while commuting to and from work. All urine excretions were collected as individual samples during the study. In personal air samples, 28 PAHs were measured, and in urine samples 9 mono-hydroxylated metabolites (OH-PAHs) from 4 parent PAHs (naphthalene, fluorene, phenanthrene and pyrene) were measured. Naphthalene was found at higher concentrations in air samples collected at the subjects' residences, whereas PAHs with four or more aromatic rings were found at higher levels in samples taken while commuting. Urinary OH-PAH biomarker levels increased following reported high inhalation and/or dietary exposure. On days with a low PAH diet, the total amount of inhaled naphthalene during each 24-hour period was well correlated with the amount of excreted naphthols, as was, to a lesser extent, fluorene with its urinary metabolites. During days with a high dietary intake, only naphthalene was significantly correlated with its excreted metabolite. These findings suggest that this group of non-occupational subjects were exposed to naphthalene primarily through indoor air inhalation, and exposed to other PAHs such as pyrene mainly through ingestion.

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

“…3 Furthermore, inhalation is the dominant exposure route for small PAHs such as NAP in general population. 39,40 For most FLU, PHE and PYR metabolites, the amount of OH-PAHs excreted within 24 h after the dietary exposure was correlated or marginally correlated with the amount of ingested barbecued chicken, and thus, correlated with the amount of ingested PAHs. This is encouraging, especially considering the small sample size (9 participants or N=9).…”

“…Similar 1-NAP-specific spikes have also been observed in several previous studies on non-occupationally exposed reference populations. 34,40 Considering the wide usage of the carbaryl pesticides and its dominant contribution to urinary 1-NAP when exposed, we recommend not using 1-NAP, and relying on 2-NAP instead as the biomarker to naphthalene exposure in future biomonitoring studies.…”

“…The urinary biomarkers reflect total exposure from all sources, and inhalation can be the dominant exposure route for NAP in general population. 39,40 In addition, naphthalene analysis can be challenging and is often omitted in food analyses. 41 In this study, the food was analyzed by a commercial lab without using isotopically labeled internal standards and we did not have control over the data quality.…”

Sources and potential health risk of gas phase PAHs in Hexi Corridor, Northwest China

“…Inhalation has been thought to be a major route of human exposure to PAH because of the presence of high level PAHs in the atmosphere (ATSDR 1995;Li et al 2010). Atmospheric PAHs can be present in particulate matters or gas phase, depending on the different vapor pressure of PAH congeners (Chang et al 2006;Park et al 2002).…”

Noncovalent interactions between hydroxylated polycyclic aromatic hydrocarbon and DNA: Molecular docking and QSAR study

“…In most cases, PAHs can be hydroxylated by CYP450-oxidases, which is a key step in the activation process to produce the polar biochemically reactive electrophilic species (ultimate carcinogenic metabolites) capable of interacting with cellular macromolecules, particularly nucleic acids and proteins (Zhou et al, 2003). Most recently, hydroxylated PAHs (HO-PAHs) have emerged and are causing increasing concern due to their detection in human hair (Schummer et al, 2009), urine (Campo et al, 2010Li et al, 2010c), and expired air samples (Li et al, 2010c); these agents have even been found in the bile of deep-sea fish (Escartin and Porte, 1999). Previous studies have shown that certain HO-PAHs can affect hormone homeostasis, as they act as potent ligands for binding to the aryl hydrocarbon receptor (AhR) and even interact with DNA (Wang et al, 2009a;Wenger et al, 2009;Ohura et al, 2010;Wei et al, 2010).…”