Exposure to polycyclic aromatic hydrocarbons in occupational versus urban environmental air

To evaluate the balance between occupational and environmental exposure to suspended particulate matter (SPM) and polycyclic aromatic hydrocarbons (PAHs), comparison measurements were performed in a coal-fired power plant and the urban atmosphere from the town nearby.

The analysis of SPM for PAH content was done according to a high-performance liquid chromatography (HPLC)-based method. The microscopic assessment was performed using scanning electron microscopy (SEM) by silver coverage of the samples derived by air filter.

Contrary to expectations, the results showed low levels of particle-bound PAHs in the occupational environment (< 1 ng benzo(a)pyrene/m3 air) and high levels in urban air (range 80-1250 ng benzo(a)pyrene/m3). The SPM collected from the power plant exhibited non-respirable characteristics (particles larger than 10 microm), whereas urban SPM almost exclusively contained respirable airborne particles (<3 microm).

The PAH burden, combined with the enhanced probability of respiratory absorption, confers a much greater hazard potential to the urban SPM. Under these conditions, in areas or countries in which old technologies remain in use, occupational exposure to SPM containing PAHs might represent a severe underestimation of the total risk as it does not take into account the background air pollution.