Railway accident with benzene release into the environment in 2025: estimation of health risks from available data

The aim of the study was to assess potential health risks associated with a large-scale environmental release of benzene following a railway accident in Moravia, Czech Republic, in 2025, with emphasis on differences between population and occupational exposure.

An assessment of potential health risks associated with exposure was performed using available environmental monitoring data. Conservative exposure scenarios were defined for the general population and for remediation workers. Non-carcinogenic risk was expressed as the hazard quotient (HQ), and carcinogenic risk as excess lifetime cancer risk (ELCR).

Short-term peaks in ambient air benzene concentrations were observed in the period immediately following the accident and during remediation activities, with occasional hourly values reaching the order of tens of µg.m^-3. During the accident and its immediate aftermath, benzene concentrations at the accident site ranged from < LOQ-32.3 mg.m^-3 (LOQ - limit of quantification) in soil gas (March-April 2025), 0.0004-2.43 g.l^-1 in groundwater (March-May 2025), < LOQ-19.9 µg.l^-1 in surface water (March-June 2025), and < LOQ-849.7 mg.kg^-1 in soils (March-April 2025). Extreme values were confined to the immediate accident zone and represented the dominant exposure for workers rather than residents. For the general population, HQ values remained below 1 and ELCR ranged from 10^-6 to 10^-5. In contrast, remediation workers exhibited substantially higher risks, with HQ values reaching 10⁴-10⁵ and ELCR up to 10^-3, particularly for inhalation exposure.

While population exposure remained within acceptable limits, occupational exposure during remediation represented the dominant health risk. Two workers involved in remediation activities were excluded from further work based on the results of biological monitoring of benzene exposure. The results highlight the need for strict exposure control and health surveillance of exposed workers.