Assessments of contamination and human health risks of heavy metals in the road dust from a mining county in Guangxi, China

ABSTRACT

A total of 32 road dust samples were collected from mining areas and a control area in Nandan County, Guangxi, in order to investigate the contamination characteristics of heavy metals and associated health risks to local residents. The results indicated that elevated concentrations of As, Cd, Cu, Pb, Sb, and Zn were found in road dust in mining areas compared with control areas and background values. Pearson's correlation analysis and principal component analysis indicated that As, Cd, Cu, Pb, Sb, and Zn in road dust mainly originated from anthropogenic sources (e.g., vehicles emission, mining activities, and smelting activities), whereas Cr, Co, and Ni were associated with natural sources (e.g., soil weathering). Furthermore, noncarcinogenic hazards to both adults and children were found in mining areas, while noncarcinogenic health risks in the control area were negligible. The health hazard was mostly ascribed to the ingestion, followed by the dermal contact, and the inhalation. The cancer risks from As, Cd, Co, Cr, and Ni in all studied areas were within safe levels as the R values were below the threshold of 1 × 10⁻⁶.

KEYWORDS:

• heavy metals
• road dust
• contamination assessment
• health risk assessment
• Nandan County

Additional information

Funding

This work was supported by the National Natural Science Foundation of China under Grant number 41261082 and 41161056.