Pollution Characteristics, Sources, and Health Risk Assessments of Potentially Toxic Elements in Community Garden Soil of Lin'an, Zhejiang, China

The characteristics, sources and risk assessment of heavy metal pollution in community garden soil of Lin'an District were evaluated. The 28 soil samples from community garden were collected for determination of 7 heavy metal elements. The Geostatistical analysis, Spearman correlation coefficient, Principal component analysis and PMF model have explored sources of heavy metal pollution. The health risk assessment model has assessed ecological risk of heavy metals. The results revealed that average concentration of As, Cd, Cr, Cu, Ni, Pb and Zn were 16.0, 0.158, 76.1, 34.6, 45.8, 20.9 and 166 mg kg(-1), respectively. Whereas As, Cd, Cr, Cu, Ni and Zn were higher than background values. The spatial distribution of heavy metal pollution in the southwest of the study area was higher than northeast. The pollution sources of Cd, Cu, Ni and Zn in the study area were due to agricultural activities (42.9%), Cr and Pb were from traffic sources (36.2%), and As was domestic pollution (20.9%) according to Spearman correlation coefficient, Principal component analysis and PMF model. The non-carcinogenic risks of As (5.39), Cr (3.53) and Ni (2.07) have a value of 1, which indicated significant risk. The potentially toxic elements have not exceeded maximum threshold of USEPA, with regard to carcinogenic risk, while As (3.37E-05) and Cr (5.74E-05) have exceeded the safety range. It is concluded that soils of community gardens are facing pollution problem due to potentially toxic elements which require environmental monitoring of the soil to reduce risk of human health.