ABSTRACT
Objective To analyze characteristics of heavy metals in metro station’s airborne PM2.5 and to evaluate its health risk in a South China city. Methods A metro stations were selected for the study. Sampling sites of metro station included ground control, station hall and platform. The PM2.5 sampling was conducted one time per day for three consecutive days. The concentrations of ten heavy metals (As、Cr、Cd、Ni、Hg、Pb、Mn、Sb、Se、Cu) were determined. Inhalation exposure to these heavy metals2.52.5 range from 0.06 ng/m3 to 49.22 ng/m3. The concentrations of Mn、Cr and Ni in metro station’s airborne PM2.5 were respectively 3.75 times, 2.23times and 2.12 times higher than those in ground control. Increased lifetime cancer risk of carcinogenic heavy metal Cr exposure outrange the acceptable level (10-6) when its exposure time exceed 5 hours per day for lifetime. Cancer risk of carcinogenic heavy metal As exposure outrange the acceptable level (10-6) when its exposure time for adult male population exceed 8 hours per day for lifetime. Non-carcinogenic hazards risks of heavy metal Mn、Cu、Pb、Se、Hg and Sb in metro station’s airborne PMPM2.5 were little. Conclusions Airborne particulate matter in metro station has become one of the important sources of heavy metal exposure. Further attention should be paid to the possible carcinogenic risk of heavy metals in metro station’s airborne PM2.5 for long-term exposure.