Breath measurements as volatile organic compound biomarkers.

Abstract

A brief review of the uses of breath analysis in studies of environmental exposure to volatile organic compounds (VOCs) is provided. The U.S. Environmental Protection Agency's large-scale Total Exposure Assessment Methodology Studies have measured concentrations of 32 target VOCs in the exhaled breath of about 800 residents of various U.S. cities. Since the previous 12-hr integrated personal air exposures to the same chemicals were also measured, the relation between exposure and body burden is illuminated. Another major use of the breath measurements has been to detect unmeasured pathways of exposure; the major impact of active smoking on exposure to benzene and styrene was detected in this way. Following the earlier field studies, a series of chamber studies have provided estimates of several important physiological parameters. Among these are the fraction, f, of the inhaled chemical that is exhaled under steady-state conditions and the residence times, t, in several body compartments, which may be associated with the blood (or liver), organs, muscle, and fat. Most of the targeted VOCs appear to have similar residence times of a few minutes, 30 min, several hours, and several days in the respective tissue groups. Knowledge of these parameters can be helpful in estimating body burden from exposure or vice versa and in planning environmental studies, particularly in setting times to monitor breath in studies of the variation with time of body burden. Improvements in breath methods have made it possible to study short-term peak exposure situations such as filling a gas tank or taking a shower in contaminated water.

Relationships between levels of volatile organic compounds in air and blood from the general population

“…For example, while Egeghy et al (2000) found that benzene in personal air and exhaled breath were highly correlated (r ¼ 0.77 for the logged levels) following short (1-10 min) exposures at levels ranging from approximately 4 p.p.b. to 10 p.p.m., Wallace et al (1996) would not recommend exhaled breath as a surrogate for VOC exposure at levels less than 1 p.p.m. (Wallace et al, 1996).…”

“…to 10 p.p.m., Wallace et al (1996) would not recommend exhaled breath as a surrogate for VOC exposure at levels less than 1 p.p.m. (Wallace et al, 1996). Similarly, our previous study of benzene biomarkers found that albumin adducts of some reactive benzene metabolites, namely, benzene oxide and 1,4-benzoquinone, were clearly related to occupational benzene exposures above 1 p.p.m.…”

Capillary thermal desorption unit for near real-time analysis of VOCs at sub-trace levels. Application to the analysis of environmental air contamination and breath samples

“…The possibility of using breath tests to evaluate exposure to ETS is very promising given that it is a procedure that is safe and easy to perform. Preliminary studies have suggested that some VOCs detected in breath samples may be biomarkers (e.g., 1,3-butadiene, benzene, 2,5-dimethylfuran) [8][9][10][11][12][13][14][15][16].…”

Approaches to environmental exposure assessment in children.

“…Several urinary metabolite assays are available but these methods generally lack sensitivity and/or specificity when applied to environmental exposures. However, breath sampling of VOCs is a valid method for evaluating environmental exposure (32,33). This methodology is especially well suited for children because of its noninvasiveness and ease with which samples can be collected.…”