INFERNO - how do chemicals affect the reproductive health of firefighters?

On September 1, 2021, Dr Jana Navrátilová, a postdoc at the Exposure and Health Risk Assessment group, began her two-year Marie Skłodowska-Curie Widening Fellowship (MSCA_WF) funded by the European Horizon 2020 program. MSCA_WF actions support the development of human resources, mobility, and the careers of researchers in the European Research Area. The INFERNO project, implemented at RECETOX (Masaryk University, Faculty of Science), involves close cooperation among RECETOX, Brno University Hospital Center for Assisted Reproduction, and the School and Training Facility of the Czech Fire and Rescue Services Brno.

INFERNO (Investigation of the effects of per- and polyfluoroalkyl substances on reproductive health in the fire-fighting environment) aims to clarify the influence of selected chemical substances on the reproductive health of firefighters. During training and interventions, firefighters are exposed to various toxic substances, such as perfluorinated and polyfluorinated substances, and harmful occupational conditions, such as extreme heat, which can adversely affect their fertility. The growing debate on the impacts of these chemicals on male fertility in the professional community, accompanied by the rise in infertility in the population as a whole, affecting at least one-fifth of Czech couples and up to 48.5 million couples worldwide, underscores the significance of this project.

Perfluorinated and polyfluorinated substances (PFAS) are a diverse group of organic substances which, due to their unique properties, are used in industry, in a wide range of consumer products, and in mixtures used for extinguishing specific types of fires, such as aviation and hydrocarbon fuel fires. However, being highly stable, these substances (due to fluorine atoms) are resistant to decomposition and thus are persistent and gradually accumulate in the environment. Some are considered dangerous to health simply due to the combination of their properties and persistence. They are carcinogenic, immune, and endocrine system disruptors and have adverse effects on fertility in both men and women.

Firefighters are exposed during their service to perfluorinated and polyfluorinated substances to a much greater extent than the general population. The use of fire-fighting foams containing a mixture of these substances is thus assumed to put firefighters at higher risk of being affected. In the INFERNO project, concentrations of these substances will be measured in the blood and semen of firefighters. Subsequently, these measurements ​​will be correlated with spermiograms (i.e., microscopic analysis of semen), evaluating the number, shape, and motility of the sperm. Additionally, the project will investigate the specific mechanism of action of perfluorinated and polyfluorinated substances affecting male fertility, using cell lines, such as testicular Leydig cells. Leydig cells, located in the seminiferous tubules of the testes, produce the sex hormone testosterone, thereby affecting genitals development and sperm maturation. Impairment in the function of these cells can significantly alter male fertility. The results of the spermiograms will be communicated individually to study participants.

Research results will also be communicated directly with fire rescue services and other relevant professionals to improve decontamination and other practices associated with exposure risks. Moreover, the results will provide valuable biomonitoring data in the context of the European Commission’s newly adopted EU Strategy for the Sustainability of Chemicals, which aims to ban entirely perfluorinated substances.