Organochlorine Compounds in Peat Deposit of Northern Boreal Bog

This paper presents the results of a study of the physicochemical conditions and contamination of a peat deposit in a representative northern boreal bog with the persistent organic pollutants (POPs), hexachlorobenzene (HCB), pentachlorobenzene (PeCB), and pentachlorophenol (PCP), as well as compounds from another organochlorine compounds, the chlorinated phenols (CPs). Despite the remoteness from the industrial sources of these compounds, a wide range of the organochlorine compounds were detected in the studied peat deposit. The maximum concentrations of HCB, PeCB, and PCP reached 9.4 ng/g, 0.5 ng/g, and 2.6 ng/g, respectively. Moreover, the total CPs content exceeded 1400 ng/g. It was established that the main pathway of the input of POPs into peat deposit was the atmospheric deposition of particulate matter (ash particulates) transported from local emission sources and sources located in low-latitude territories and adjacent regions. The low mobility of POPs, as well as the high sorption capacity of high-moor peats in relation to compounds with similar properties, lead to their concentration in the upper aerated 40 cm layer of the peat deposit, the formation of which coincides with the age of the "chloroorganic society." Factor and correlation analysis revealed that the key factor determining the distribution of these compounds in normally functioning bogs is the mineral component (ash content of peat and pore water mineralization).