Spatial Distribution, Potential Ecological and Health Risk Assessment of Heavy Metals in Surface Soils from Tobacco Cultivating Areas of Linyi, Shandong Province, China

The spatial distribution and risk assessment of heavy metals are the foundation of soil remediation. The heavy metals (As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn) in the surface soils of tobacco (Nicotiana tabacum L.) fields in Linyi City of Shandong Province, a traditional tobacco growing area, were collected and determined, and the difference between counties and soil types was analyzed, with spatial distribution maps generated by the geographic information system. The enrichment of heavy metals in soil was assessed by index of geo-accumulation and pollution index, and the risk assessment included potentially ecological risk and health risk assessment. The results showed that, (1) the mean heavy metal concentrations in Linyi tobacco growing soils were 3.85, 0.09, 47.56, 14.45, 0.07, 18.04, 17.82 and 29.21 mg/kg, respectively; (2) the concentrations of heavy metals in soil samples from north, middle and southwest of Linyi were relatively higher than those from other areas; (3) some soil samples were enriched with Cd and/or Hg, which were the only two metals posing a potentially high ecological risk to the local environment, and the order of ecological risk for the heavy metals was Hg > Cd > As > Ni> Pb > Cu > Cr > Zn; (4) The health risk assessment showed no considerable non-carcinogenic or carcinogenic risks for children and adults from these elements.