The overarching aim of this study is to quantify the link between occupational exposure to property fire smoke and cancer risk among structural firefighters in the State of Ohio. Previous studies have relied on qualitative measures of exposure such as career length and career number of fire calls to determine the cancer risk of structural firefighting. In addition to this approach, the determination of cancer risk in the current study will also be investigated based on quantitative measures of exposure comprising of measurements of contaminants that are emitted during property fires in biological fluid. These include flame retardants (ploybrominated diphenyl ethers [PBDEs]), dioxin-like compounds, and polycyclic aromatic hydrocarbons (PAHs). Comparisons of the blood concentrations of the contaminants will be made between firefighters who have recently been diagnosed with cancer and those who have never been diagnosed with the disease. The study aims to collect quantitative measures of occupational exposures of structural firefighters to property fire smoke by measuring contaminants emitted during structural and vehicular fires in the blood (PBDEs) and urine (organophosphate flame retardants [OPFRs]). The study will also investigate factors that are associated with exposure. It is expected that the accomplishment of the study objectives will contribute towards the identification and documentation of health risks of fire smoke exposures among structural firefighters, and contribute knowledge relevant for developing more effective exposure mitigation strategies and for assessing the effectiveness of such strategies in reducing exposure and related cancer risk.