Gas–particle concentrations and distribution of aliphatic hydrocarbons, PAHs, PCBs and PCDD/Fs in the atmosphere of Athens (Greece)

Abstract

Air samples were collected at the urban center, a background site, and the adjacent coastal area of the metropolitan area of Athens during July 2000. Gas and particle phase concentrations of aliphatic hydrocarbons, α, β-hopanes, polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and 2,3,7,8-substituted polychlorinated dibenzo- p-dioxins and dibenzofurans (PCDD/Fs) were identified and measured. Total concentrations of aliphatic hydrocarbons, ranged between 943.0 ng m −3 (urban site) and 947.1 ng m −3 (coastal area) in the gas and from 141.8 ng m −3 (coastal site) up to 469.0 ng m −3 (urban center) in the particulate phase. The total concentration of α, β-hopanes (12 homologues) in the urban area was ca. 0.2 ng m −3 in the gas and 1.0 ng m −3 in the particulate phase. Total PAH concentrations (∑PAHs of 20 members) ranged from 3.5 ng m −3 (background site) to 26.0 ng m −3 (urban center) in the gas and from 1.3 ng m −3 (coastal area) up to 5.0 ng m −3 (urban center) in the particulate phase. The total concentration of PCBs (∑PCBs of 38 congeners) in the gas plus the particulate phase of the atmosphere ranged from 80.5 pg m −3 (background site) up to 348.6 pg m −3 (urban center) and the corresponding concentration of PCDD/Fs ranged from 166.6 fg m −3 (background site) up to 701.5 fg m −3 (urban center), respectively. Gas–particle partition coefficients K p of n-alkanes, PAHs, PCBs and PCDD/Fs were well correlated ( R 2=0.50–0.99) with the sub-cooled liquid vapor pressure P L o . The average slopes m r of log K p versus log P L o for n-alkanes (−0.46) and PCBs (−0.44) were low compared to other urban areas. The corresponding m r values for PAHs (−0.57), PCDDs (−0.78) and PCDFs (−0.75) are comparable to those obtained in other urban areas.