Firefighters' multiple exposure assessments in practice.

During the past decade, more research has focused on firefighters' multiple exposures via multi-route exposure. Multi-route exposure can alter the kinetics of chemicals; this has brought changes to the recommendations on biomonitoring. In addition, the possibility that the chemicals in smoke have additive and synergistic effects has not been consistently taken into account. In this study, biomonitoring and occupational hygienic measurements were used to determine smoke diving trainers' exposure to smoke in conventional and modern simulators. Biological action limit values (BALs) for 1-hydroxypyrene, linked with the ratio of pyrene to benzo[a]pyrene, were established for conventional and modern simulator types. The additive and synergistic effects for the main compounds detected in the air during the suppression of a fire were also calculated. According to the biomonitoring results, dermal exposure played a role in exposure to polycyclic aromatic hydrocarbons (PAHs), and it seemed to delay the excretion of 1-hydroxypyrene and 1-naphthol. The calculated BALs for 1-hydroxypyrene were 6 nmol/L and 53 nmol/L for the conventional and modern simulators, respectively. The combined cancer and eye disorders or upper respiratory tract irritation effects of volatile organic compounds (VOCs) in the conventional simulator were from 6.5 to 7.0-fold higher than in the modern simulator.