Air and soil concentrations of persistent organic pollutants in Bursa (Türkiye) and Yurimaguas (Peru): air-soil exchange and gas-phase flux

Abstract

The study of persistent organic pollutants (POPs) in different environments has helped to understand the behavior and distribution of these pollutants worldwide. Many developed and developing countries have extensive data on the presence of these pollutants, especially in ambient air and soil. However, the simultaneous measurement of air and soil is less frequent, despite offering the opportunity to characterize air-soil exchange. Moreover, such measurements in upper-middle-income countries such as Turkey are very limited and null in Peru. Both countries also offer unique opportunities to characterize the air-soil exchange since Peru has a semi-arid subtropical desert climate and Turkey has a Mediterranean climate. Therefore, the aim of this study is to determine the simultaneous POP concentrations (polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and organochlorine pesticides (OCPs)) in ambient air and soil in Turkey and Peru and to reveal the POP exchange between air and soil and flux amounts in the gas phase. POP concentrations in ambient air were measured higher at sampling points in Turkey, while POPs in soil were measured similarly in both countries. Also, the air-soil fugacity fractions indicated net volatilization for low molecular weight PAH and PCB congeners, but net deposition for high molecular weight congeners; equilibrium states were found for medium molecular weight congeners. Fugacity fractions did not change with their molecular weights for OCPs. It has been determined that soil acts as a “secondary source” for low molecular weight PAH and PBC congeners in the atmosphere, while the atmosphere acts as a “sink” for high molecular weight PAH and PCB congeners in the soil. Finally, cancer risk calculations for adults and children have been made, both via inhalation of atmospheric POPs and uptake of POPs from the soil. According to the calculations, no health risks were found for both air and soil for adults and children.