Biological monitoring of wood-smoke exposure

Abstract

It has been clearly established that exposure to wood smoke is associated with a variety of adverse health effects in humans. However, we still have much to learn about the relationship between wood-smoke exposure and disease, including determination of what should be considered a "safe" level of exposure, and whether wood smoke should be regulated separately from other sources of air pollution. To help answer these questions, improved measures of exposure in populations exposed to wood smoke are required. In this mini-review we discuss how biomarkers of exposure can be used to complement the current suite of methods used to assess wood-smoke exposures. We critically review the compounds that are currently being evaluated as biomarkers of exposure to wood smoke, and we identify the strengths and weaknesses of these compounds. We find that, in general, these compounds show promise in situations where wood-smoke exposures are high, but where exposures are low non-wood-smoke sources are likely to be the major determinants of biomarker levels. We also outline a research framework that will move this field forward and maximize the potential for wood-smoke biomarkers to add value to epidemiological studies of wood-smoke health effects.

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

“…This is the first study that we know of measuring all three proposed urinary woodsmoke biomarkers, 17 i.e. urinary levoglucosan, 19 methoxyphenols, 32 and OH-PAHs.…”

“…Diet can also be a potential source for methoxyphenols (food containing woodsmoke flavoring) and levoglucosan (caramelized sugar). 17 Hence, all three urinary woodsmoke biomarker classes are limited with regard to specificity, and OH-PAHs have the most potential sources. Nonetheless, in a well-designed study, the alternative sources can be avoided or minimized by employing appropriate dietary and activity restrictions, which would enable linking the biomarkers with the target source.…”

“…Several chemicals or classes of chemicals have been proposed as woodsmoke exposure biomarkers, 17 such as urinary levoglucosan 18–20 and methoxyphenols. 21 Urinary hydroxylated PAHs (OH-PAHs), a group of PAH metabolites, 22–25 have been used as biomarkers of exposure to PAHs, with 1-hydroxypyrene (1-PYR) as the most commonly used indicator.…”

Human urinary mutagenicity after wood smoke exposure during traditional temazcal use

“…Existing monitoring methods for wood smoke exposure assessment include personal exposure devices for particulate matter, monitoring of exhaled or blood carbon monoxide (CO) levels and monitoring of urinary concentrations of various components of wood smoke such as PAHs (or their metabolites), potassium, methoxyphenols and levoglucosan (for a review see Simpson and Naeher) (14). Urinary methoxyphenol concentration was assessed in individuals from the same study population as that examined in the current work, comparing levels between individuals who use open fires for cooking versus vented wood stoves (i.e.…”

Secondary organic aerosol formation from biomass burning intermediates: phenol and methoxyphenols

“…Emission rates for methoxyphenol species from biomass burning have been estimated to range from 420-900 mg kg −1 fuel (Hawthorne et al, 1989;Hawthorne et al, 1992;Schauer et al, 2001). In addition to the significant emission factors of these compounds, guaiacol, which is emitted from both hard and soft wood combustion, and syringol, which is emitted primarily from soft woods, have been proposed as aerosol markers for wood combustion as well as biomarkers to determine human exposure levels (Dills et al, 2001;Simpson and Naeher, 2010).…”