Exposure and Health Risk Assessment of Heavy Metals Contained in Particulate Matter Emitted from Steel Plants

摘要

The objective of this study was to investigate the exposure and health risk assessment of particulate matter (PM) emitted from steel plants in metro Kaohsiung. Both personal exposure and environmental sampling were conducted by portable personal samplers and ambient PM samplers in steel plants. Personal exposure sampling was undertaken at working places, whereas environmental sampling was conducted at the working places and outside the plants. The health risk of heavy metals for employees in the steel plants was further assessed based on the exposure and duration of PM. Results obtained from the environmental sampling at the working places showed that the highest PM concentrations were observed in the electrical arc furnace plant where the concentrations of PM1.0, PM2.5, PM10, and TSP were 36.0~195.6, 40.4~242.0, 365.7~550.0, and 1085.5~2755.0 mu g/m3, respectively. Measuring at the outside of the plants, the highest PM10 and TSP concentrations were observed at the sinter plant. Results obtained from the environmental sampling of PM at the fences of steel plants indicated that the concentrations of PM10 and TSP generally exceeded the Ambient Air Quality Standards (PM10: 125 mu g/m3, TSP: 250 mu g/m3). Results obtained from personal exposure sampling of PM showed that the highest exposure level was observed at the raw material storage field, while the lowest exposure level was found at the sinter plant. Moreover, the cancer risk of employees exposed to Cr (as Cr6+) at the blast furnace plant, the sinter plant, the raw material storage field, and the electrical arc furnace plant, exceeded the acceptable cancer risk level (10~(-5)~10~(-6)), while the hazard index of manganese (Mn) was much higher than other non-cancer risk metals. Meanwhile, exposure to PM containing Cr6+, Ni, and Mn in the steel plants was found to exceed the acceptable risk levels.