Environmental risk estimation of potentially toxic metal(loid)s (PTMs) in fine particulate dust on the surface of children's playgrounds in parks

To determine the priority control factors for risk control and management of potentially toxic metal(loid)s (PTMs) in fine particulate dust (FPD) on the surface of children's playgrounds in parks, a comprehensive study was conducted on the pollution, risks, and sources of 12 PTMs in the FPD, taking Xi'an, China as a case. The pollution, ecological and health risks of PTMs were assessed using Nemerow integrated enrichment factor, modified Nemerow integrated eco–risk index, and health risk evaluation model, combined with Monte Carlo simulation. The sources of PTMs in the FPD were quantitatively apportioned using a positive matrix factorization model. Priority control factors for PTMs risk control and management were determined based on the results of source–oriented pollution and risk assessment. The results showed that the average contents (mg kg⁻¹) of Cd (1.9), Cr (99.8), Cu (96.3), Hg (0.2), Pb (61.1), and Zn (239.4) in the FPD were considerably greater than local background values. The sources of PTMs in the FPD are industrial emission, coal combustion and medical activities, mixed source, and natural source, contributing 24.7%, 18.2%, 35.1%, and 22.1% to the total content of PTMs in the FPD, respectively. PTMs in the FPD posed a certain cancer risk to the elderly and children. Industrial emissions and mixed sources are priority control sources, while Cd and Cr are priority PTMs. It is recommended that local eco–environmental departments strengthen environmental monitoring of playgrounds, as well as management of industrial and transportation emissions, to ensure the health of residents.