Contamination assessment and health risk of arsenic exposure to stairway dust in the zinc smelting district, Northeast China.

Stairway dust samples were collected from residential communities in Huludao city to investigate population health risk of arsenic (As) exposure through stairway dust. ArcGIS software was used to analyze As spatial distribution in Huludao city. Hazard index was applied to assess health risk due to exposure to As in stairway dust. The results were that As concentrations ranged from 13.26 to 237.58 mg kg-1, and the mean value was 59.64 mg kg-1, which was seven times as high as the background value of Liaoning Province. The pattern of spatial distribution was concentric rings as the center of Huludao zinc plant, with the extension to the northeast and southwest. The average value of Igeo was 2.176, which fell into moderately polluted level. For non-carcinogenic risk, the hazard indexes were less than 1, indicating that there was almost no health risk for residents exposed to stairway dust. But population risk exposure to dust would increase rapidly with exposure time in stairway. The highest contribution to the overall figure of non-carcinogenic risk and carcinogenic risk appeared to be ingestion of substrate particles followed by inhalation pathway and dermal absorption of As in dust samples. And for carcinogenic risk, the risk values were lower than the threshold range of EPA's safe limits (1 × 10-6 and 1 × 10-4), suggesting that potential cancer risk of As due to exposure to stairway dust can be acceptable.