Short- and medium-chain polychlorinated alkanes in the air of Athens, Greece

Abstract

The atmospheric occurrence and partition between the gas and particulate phase of short- (PCAs–C_10-13) and medium-chain (PCAs–C_14-17) polychlorinated alkanes (PCAs) were investigated during two sampling campaigns in Athens city, Greece. The concentrations of PCAs ranged between 1.46 and 43.6 ng m⁻³ in the gas phase, and between 5.8 and 40.3 ng m⁻³ in the particulate phase, which were within the reported levels in Europe. Significant seasonal variation was observed for PCAs–C_10-13 and PCAs–C_14-17 in the gas phase. C₁₀Cl_6–7 and C₁₄Cl_6–8 were the predominant short- and medium-chain congeners, respectively. Gas-phase PCAs exhibited significant positive correlation with temperature, and negative correlation with relative humidity. Diagnostic ratios of medium to short-chain PCAs suggested that ΣPCAs in total suspended particle (TSP) mainly originated from local sources. Furthermore, the relationship between partitioning coefficient Kp and the subcooled liquid pressure (P_L°) was investigated. Moreover, Positive Matrix Factorization (PMF) analysis was employed to identify the potential ΣPCAs groups of sources. Finally, the estimated risk of inhalation exposure to ΣPCAs for adults and children was found to be low.