PNNL

Abstract

Exposure assessment is an integral part of industrial hygiene and occupational health. To ensure the health and safety of workers, integrated industrial hygiene methodologies often include biological monitoring strategies. Exhaled breath is an ideal matrix for measuring volatile biomarkers, particularly since the non-invasive collection of breath may improve volunteer participation. A real-time, field-portable system was developed to analyze undiluted exhaled air from experimental animals and humans. The system combines 1) an ion-trap mass spectrometer capable of atmospheric sampling; 2) a breath interface for continual analysis of the exhaled breath stream; 3) chemical dosimeters that are analyzed in the field/workplace; and 4) physiologically based pharmacokinetic (PBPK) models to estimate total exposure and internal target tissue dosimetry. The intent of this development was to provide new instrumentation to evaluate volatile chemical exposures as part of a daily monitoring program. For example, the system was designed to monitor a worker every time they enter and leave a work environment - a vast improvement over current 8-hr integrated monitoring strategies. To evaluate the system in actual work environments, field tests were conducted using volunteers providing exhaled breath samples before and after each specific job task. In these field studies, several volunteers had post-task breath levels higher than pre-task levels. Compared to the breath analysis findings, chemical dosimeters underpredicted exposures, particularly for longer sampling intervals where the volume of air sampled may have diluted exposures. The results of these field studies illustrate the utility of monitoring workers for exposures at numerous times throughout the day, particularly when job-specific tasks may indicate a potential for exposure.