Polycyclic aromatic hydrocarbons in the Siberian Arctic seas sediments

Area of Science:

• Environmental Science
• Marine Chemistry
• Arctic Research

Background:

• Polycyclic Aromatic Hydrocarbons (PAHs) are persistent organic pollutants accumulating in Arctic marine sediments.
• Long-range transport from lower latitudes contributes significantly to Arctic PAH contamination.
• This study revisits remote Siberian Arctic seas after a 25-year gap.

Purpose of the Study:

• To assess current Polycyclic Aromatic Hydrocarbon (PAH) levels and sources in Siberian Arctic seas.
• To provide an updated understanding of PAH contamination in understudied Arctic regions.
• To compare current PAH concentrations with historical data from the 1990s.

Main Methods:

• Analysis of 16 priority PAHs and methylnaphthalenes in 24 sediment samples.
• Gas chromatography - tandem mass spectrometry (GC-MS/MS) was employed for precise quantification.
• Samples were collected from the Kara, Laptev, and East Siberian Seas in October 2020.

Main Results:

• Sum PAH concentrations ranged from 31 to 223 ng/g, with phenanthrene, benzo[b]fluoranthene, benzo[k]fluoranthene, naphthalene, and methyl derivatives being major contributors.
• The Laptev Sea exhibited the highest overall PAH levels.
• No correlation was found between PAH concentrations and organic or black carbon content.

Conclusions:

• The toxic equivalent concentration suggests a generally safe environmental situation in the studied region.
• PAH levels are comparable to those from the 1990s, indicating persistent pollution.
• Primary PAH sources identified are coal/biomass combustion and liquid fuel burning, with a minor contribution from petroleum sources.