Potentially toxic element (PTE) pollution in farmland soil is a global problem. It is vital to clarify the contributions of farmland soil PTE from different sources to potential ecological risk (PER) and human health risks (HHR), but the existing research methods were incomplete. This study explored a comprehensive scheme that combined source contribution and risk assessment to quantitatively assess PER, HHR and the priority pollution sources. enrichment factor (EF) and pollution load index (PLI) were utilized to estimate the features of enrichment and contamination of PTE in farmland soil. Furthermore, spatial distribution characteristics of PTE and positive matrix factorization (PMF) were combined to distinguish and ascertain the sources of PTE, and the PER and HHR model based on PMF were applied to evaluate the ecological and human health risks in different sources. Taking Puning District as an example, four sources of farmland soil PTE were quantitatively allocated. For ecological risk, the study area was at moderate ecological hazard, with industrial activities (53.67%) contributing the most. The mean of Hg was 69.82, reaching medium ecological risk. For human health risks, both adults and children had no non-carcinogenic risk in the study area, and the natural source was the greatest contributor, followed by agricultural activities. The total carcinogenic risk index (TCRI) values for adults and children were 1.40E-05 and 2.75E-05, respectively, showing no significant carcinogenic risk. Furthermore, compared with adults, the health risks of children, whether noncarcinogenic or carcinogenic, were higher than those of adults.

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In this research, enrichment factor (EF) and pollution load index (PLI) were utilized to explore the contamination characteristics of toxic elements (TEs). The results exhibited that the study area was mainly moderately polluted, and the EF values of Cd, Zn, Pb, Cu and Sb were all > 1, which were cumulative. The concentrations of Cr, Cu, Zn and Pb increased with the decrease of dust particle size. The investigation results of chemical speciation and bioavailability of TEs showed that Zn had the highest bioavailability. Three sources of TEs were determined by positive matrix factorization (PMF), Pearson correlation analysis and geostatistical analyst, comprising factor 1 mixed sources of industrial and transportation activities (46.62%), factor 2 natural source (25.56%) and factor 3 mixed source of agricultural activities and the aging of park infrastructures (27.82%). Potential ecological risk (PER) and human health risk (HHR) based on PMF model were exploited to estimate PER and HHR of TEs from different sources. The PER value of TE in the park dust was 114, indicating that ecological risk in the study area was relatively high. Factor 1 contributed the most to PER, and the pollution of Cd was the most serious. There were no signi cant carcinogenic and non-carcinogenic risks for children and adults in the study area. And factor 3 was the biggest source of non-carcinogenic risk, As, Cr and Pb were the chief contributor to non-carcinogenic risk. The primary source of carcinogenic risk was factor 2, Cr was the cardinal cancer risk element.

In this research, enrichment factor (EF) and pollution load index (PLI) were utilized to explore the contamination characteristics of toxic elements (TEs). The results exhibited that the study area was mainly moderately polluted, and the EF values of Cd, Zn, Pb, Cu and Sb were all > 1, which were cumulative. The concentrations of Cr, Cu, Zn and Pb increased with the decrease of dust particle size. The investigation results of chemical speciation and bioavailability of TEs showed that Zn had the highest bioavailability. Three sources of TEs were determined by positive matrix factorization (PMF), Pearson correlation analysis and geostatistical analyst, comprising factor 1 mixed sources of industrial and transportation activities (46.62%), factor 2 natural source (25.56%) and factor 3 mixed source of agricultural activities and the aging of park infrastructures (27.82%). Potential ecological risk (PER) and human health risk (HHR) based on PMF model were exploited to estimate PER and HHR of TEs from different sources. The PER value of TE in the park dust was 114, indicating that ecological risk in the study area was relatively high. Factor 1 contributed the most to PER, and the pollution of Cd was the most serious. There were no significant carcinogenic and non-carcinogenic risks for children and adults in the study area. And factor 3 was the biggest source of non-carcinogenic risk, As, Cr and Pb were the chief contributor to non-carcinogenic risk. The primary source of carcinogenic risk was factor 2, Cr was the cardinal cancer risk element.