PAHs in the atmospheric aerosols and seawater in the North–West Pacific ocean and sea of Japan

Abstract

PAHs were analyzed in samples of atmospheric aerosols and suspended matter in seawater collected in the Sea of Japan, Sea of Okhotsk and the North-Western Pacific in June–July 2012. The concentrations of Σ(15) PAHs in the suspended matter of seawater ranged between 1984.7 pg/L to 30260.3 pg/L. The concentration of Σ(14) PAHs in marine aerosols ranged from 17.09 pg/m3 on June 19–22, 2012 in the northern part of the Sea of Japan, the La Perouse Strait to 142.47 pg/m3 on June 25–28, 2012 near middle Kuril Islands. The results of diagnostic ratios analysis indicate that the primary sources of PAH are pyrogenic. This paper discusses the main anthropogenic (coal-fired power plants and population) and natural sources (wildfires) of PAHs and their effect on the concentration of these compounds in the marine air and suspended matter of seawater. Long-range atmospheric transport of PAHs from the continent to the ocean is shown using HYSPLIT backward trajectories. Active fire products (MODIS and VIIRS) data were used to build a regression model. The model as a whole explains 58% and 75% of the Σ 5-ring PAHs and BaP variations in seawater in June–July 2012, respectively. The analysis shows that anthropogenic sources were not a significant contribution factor for PAHs in the seawater at the Sea of Japan during this period.