Assessing polycyclic aromatic hydrocarbons in the marine atmosphere on a transect across the Southwest Atlantic Ocean

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous and semivolatile pollutants associated with emissions from both natural and anthropogenic sources. For decades, the atmosphere has been considered an efficient vehicle for pollutants transport around the world. In order to assess the atmospheric occurrence of PAHs across a transect in the Southwest Atlantic Ocean, air samples were collected aboard the oceanographic vessel ARA Puerto Deseado (CONICET), during two consecutive research campaigns in October–November 2014. Total PAHs were dominated by gas phase levels of Phenantrene, Dibenzothiophene, Fluorene, Fluoranthene and Pyrene in a concentration range of 57–5778 pg m−3. Characteristic diagnostic ratios of some PAHs were estimated in order to assess their possible emission sources showing important contribution from petrogenic and pyrogenic origin. Additionally, air mass back trajectory calculation revealed a marked influence of air with oceanic origin, being the contribution from the South American continent scarce. PAHs levels showed a decreasing trend from the coast towards open ocean, with exception of those sites that showed continental air masses influence.