Non-targeted GC/MS analysis of exhaled breath samples: Exploring human biomarkers of exogenous exposure and endogenous response from professional firefighting activity

ABSTRACT

A non-targeted analysis workflow was applied to analyze exhaled breath samples collected from firefighters pre- and post-structural fire suppression. Breath samples from firefighters functioning in attack and search positions were examined for target and non-target compounds in automated thermal desorption-GC/MS (ATD-GC/MS) selected ion monitoring (SIM)/scan mode and reviewed for prominent chemicals. Targeted chemicals included products of combustion such as benzene, toluene, xylenes, and polycyclic aromatic hydrocarbons (PAH) that serve as a standard assessment of exposure. Sixty unique chemical features representative of exogenous chemicals and endogenous compounds, including single-ring aromatics, polynuclear aromatic hydrocarbons, volatile sulfur-containing compounds, aldehydes, alkanes, and alkenes were identified using the non-targeted analysis workflow. Fifty-seven out of 60 non-targeted features changed by at least 50% from pre- to post-fire suppression activity in at least one subject, and 7 non-targeted features were found to exhibit significantly increased or decreased concentrations for all subjects as a group. This study is important for (1) alerting the firefighter community to potential new exposures, (2) expanding the current targeted list of toxicants, and (3) finding biomarkers of response to firefighting activity as reflected by changes in endogenous compounds. Data demonstrate that there are non-targeted compounds in firefighters’ breath that are indicative of environmental exposure despite the use of protective gear, and this information may be further utilized to improve the effectiveness of personal protective equipment.

KEYWORDS:

• Non-targeted analysis
• gas chromatography-mass spectrometry (GC/MS)
• automated thermal desorption (ATD)
• volatile organic compounds (VOC)
• breath research
• firefighters

Acknowledgments

The authors thank the volunteer subjects who provided breath samples. Individuals were compensated up to $599 to participate in this study. This study was approved by the NIOSH and University of Illinois Institutional Review Boards and was funded by the U.S. Department of Homeland Security Assistance to Firefighters Grant Fire Prevention & Safety program (EMW-2013-FP-00766). This study was also made possible through a partnership with the CDC Foundation. Dr. Sibel Mentese is grateful for the travel grant received from TUBITAK. The authors acknowledge Dr. Andrew McEachran and Dr. Jonathan Mosley from U.S. EPA for assisting with ACD/ChromGenius model development. This research has been subjected to EPA review and approved for publication. The findings and conclusions in this paper are those of the authors and do not necessarily represent the views of NIOSH or EPA. Mention of trade names and commercial products does not constitute endorsement or recommendation for use.

Conflict of interest

The authors declare no competing financial interest.

Supplementary material

Supplemental data for this article can be accessed here.