In vitro data for fire pollutants: contribution of studies using human cell models towards firefighters’ occupational

ABSTRACT

Firefighters are the principal line of defense against fires, being at elevated risk of exposure to health-relevant pollutants released during fires and burning processes. Although many biomonitoring studies exist, only a limited number of human in vitro investigations in fire risk assessment are currently available. In vitro studies stand out as valuable tools to assess the toxicity mechanisms involved following exposure to fire pollutants at a cellular level. The aim of the present review was to contextualize existing in vitro studies using human cell models exposed to chemicals emitted from fire emissions and wood smoke and discuss the implications of the observed toxic outcomes on adverse health effects detected in firefighters. Most of the reported in vitro investigations focused on monocultures respiratory models and exposure to particulate matter (PM) extracts collected from fire effluents. Overall, (1) a decrease in cellular viability, (2) enhanced oxidative stress, (3) increased pro-inflammatory cytokines levels and (4) elevated cell death frequencies were noted. However, limited information remains regarding the toxicity mechanisms initiated by firefighting activities. Hence, more studies employing advanced in vitro models and exposure systems using human cell lines are urgently needed taking into consideration different routes of exposure and health-related pollutants released from fires. Data are needed to establish and define firefighters’ occupational exposure limits and to propose mitigation strategies to promote beneficial human health.

KEYWORDS:

• Firefighters´ occupational exposure
• fire pollutants
• particulate matter
• in vitro assays
• toxicity
• human cell cultures

Acknowledgments

This work received additional support through UIDB/50006/2020, UIDP/50006/2020, and LA/P/0008/2020 by Fundação para a Ciência e a Tecnologia (FCT), Ministério da Ciência, Tecnologia e Ensino Superior. M.J. Bessa thanks to the FCT Post-Doc grant under the framework of the 4FirHealth project. M. Oliveira and F. Rodrigues thanks to the scientific contracts CEECIND/03666/2017 and CEECIND/01886/2020 financed by FCT/MCTES—CEEC Individual Program Contracts.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

Data sharing is not applicable to this article as no new data were created or analyzed in this study.

Additional information

Funding

This work was funded by the Portuguese Foundation for Science and Technology (FCT) through the projects 4FirHealth (PCIF/SSO/0090/2019) and Gum4Fires (2022.05381.PTDC).