Pollution Characteristics and Associated Risk Assessment of Heavy Metals in Farmland Soils From a Typical County of Hubei Province, Central China.

Knowledge from the negative impacts of the counties' anthropogenic activities on soil pollution was of great significance in China, and valuable information was urgently needed for the control and remediation of soil pollution. The current pollution levels of heavy metals (Cu, Pb, Cd, Zn, Ni, and Cr) in farmland soils were investigated in Yangxin County, Hubei Province, central China. The comprehensive results of quantitative comparison and evaluation in this study showed that Cu (144.9 ± 298.6 mg kg-1), Cd (2.9 ± 1.6 mg kg-1), and Ni (137.0 ± 111.0 mg kg-1) posed higher pollution risks to public and ecosystem health, which were higher than the corresponding soil background values. The combined results of geostatistics, spatial and statistical analysis indicated that studied heavy metals were mainly attributed to agricultural, traffic and industrial induced pollution. Overall, urgent attention should be paid to the risk reduction and management of soil Cu, Cd, and Ni pollution in the study area.

Pollution Characteristics and Human Health Risk Assessment of Heavy Metals in Street Dust from a Typical Industrial Zone in Wuhan City, Central China.

This study aimed to assess the pollution levels, sources, and human health risks of heavy metals in street dust from a typical industrial district in Wuhan City, Central China. In total, 47 street dust samples were collected from the major traffic arteries and streets around Wuhan Iron and Steel (Group) Company (WISC) in Qingshan District, Wuhan. The concentrations of heavy metals (Cr, Mn, Ni, Zn, Fe, Cu, and Cd) in street dust were determined by atomic absorption spectroscopy. Results indicated that the mean concentrations of Zn (249.71 mg/kg), Cu (51.15 mg/kg), and Cd (0.86 mg/kg) in street dust were higher than their corresponding soil background values in Hubei Province. Heavy metal enrichment is closely related to urban transportation and industrial production. The pollution level of heavy metals in street dust was assessed using the geo-accumulation method (Igeo) and potential ecological risk assessment (PERI). Based on the Igeo value, Cr, Mn, Fe, and Ni showed no pollution, Zn and Cu showed light to moderate contamination, and Cd showed moderate contamination. The PERI values of heavy metals in street dust ranged between 76.70 and 7027.28, which represents a medium to high potential ecological risk. Principal component analysis showed that the sources of heavy metals in street dust were mainly influenced by anthropogenic activities. Among the studied metals, Cu, Cr, Zn, Fe, and Mn mainly come from industrial processes, while Ni and Cd come from traffic exhaust. The non-carcinogenic risk indexes of heavy metals for children and adults are ranked as Cr > Cu > Ni > Cd > Zn. The health risks to children through the different exposure pathways are higher than those for adults. Hand-to-mouth intake is the riskiest exposure pathway for non-carcinogenic risk. In addition, Cr, Ni, and Cd do not pose a carcinogenic risk for the residents.