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. tau i 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.

A low cost MEMS based NDIR system for the monitoring of carbon dioxide in breath analysis at ppm levels

“…Data recorded from prior experiments in respiratory chambers demonstrated the concentration of CO2 exhaled must be measured to within an accuracy of 1.25 %. Exhaled CO2 is usually in the range of 4-5 % [7].…”

Applicability of non-invasively collected matrices for human biomonitoring

“…The gaseous fraction of exhaled breath can be a good biomonitor for a wide variety of volatile substances [58,59]. The monitoring of metals in exhaled breath is less well documented, although Mutti et al [60] show that toxic metals and transition elements are detectable in exhaled breath condensate (EBC).…”

“…This may have potential in the assessment of the target tissue dose for substances with potential pneumotoxic activity, such as Cd, Co or Ni [28,60]. A disadvantage of measuring biomarkers of exposure in the gaseous phase of exhaled air is that the residence time of substances are generally rather short, in the order of minutes or hours [58]. …”

Erfassung der Humanexposition mit organischen Verbindungen in Innenraumumgebungen

“…B. Blut, Blutplasma, Blutserum, Urin, Haar, Muttermilch und Atemluft. Die Atemluftanalyse dient vor allem dem Nachweis von Pathologien, findet aber auch Anwendung für die Expositionsermittlung und die Untersuchung von Stoffwechselvorgängen . Haar wurde verwendet, um Metalle und persistente organische Verbindungen zu analysieren .…”