Spatial distribution of trace elements (As, Cd, Ni, Pb) from PM aerosols and human health impact assessment in an Eastern European country, Romania.

In the present study, the concentrations of trace elements in PM were determined and analyzed at 115 monitoring stations in Romania throughout the period 2009-2018. The spatiotemporal distribution of trace element concentrations of PM, the source apportionment and health impact assessment, was carried out. The results showed a very high multi-annual mean concentration for PM and trace elements as well. The multiannual average concentration of PM was higher by 29.75% than the World Health Organization recommendation. All studied air pollutants showed a decreasing trend during the studied years, showing with 17.84%, 50.21%, 43.36%, 11.27%, and 72.09% lower values for PM, As-, Cd-, Ni-, and Pb-, respectively, due to environmental regulations. To assess the human health impact, the hazard quotient (HQ) and cancer risk (CR) were calculated using the health risk model developed by the US Environmental Protection Agency (EPA). The Cd and Ni might present a non-carcinogenic risk to both adults and children; however, the hazard quotient values are higher than the safe limit, with 9.53 and 1.93, respectively. In addition, our study results revealed that the inhalation of As, Cd and the dermal absorption of all studied trace elements were considered as the most important risk factors for developing cancer, especially in case of adults.