Persistent organochlorine pollutants in the water ecosystems on the coast of the Kandalaksha Gulf of the White Sea

The paper presents the results of studying selected persistent organochlorine pollutants (hexachlorobenzene, pentachlorobenzene, pentachlorophenol, and pentachloroanisole) from bottom sediments of small stratified lakes at different stages of isolation from the White Sea, unaffected by anthropogenic impact.The sediment samples were collected at deep-sea stations by employees of the N. Laverov Federal Center for Integrated Arctic Research, Ural Branch of the Russian Academy of Sciences (Arkhangelsk) during complex expeditionary work in March 2019. Persistent organochlorine pollutants were extracted from air-dry samples by accelerated liquid flow extraction with a hot mixture of organic solvents with further preparation according to RD 52.24.417-2011 (RF) and ISO 14154:2005. Identification and quantitative determination of individual compounds were performed using capillary gas chromatography with electron capture detection. The presence of selected persistent organochlorine pollutants in the sediments was revealed. Their total content ranged from 9.7 to 63.6 ng g-1, with hexachlorobenzene and pentachlorophenol being found in the highest concentrations. The concentrations of the pollutants were generally assessed as not high by the Norwegian Quality Standards. The input of persistent organochlorine pollutants into the bottom sediments of the studied lakes is presumably associated with long-range transport from various sources located in low/temperate latitudes and nearby regions.