Atmospheric deposition as a transfer of substantial amount of different types of chemical contaminants from the atmosphere to all types of environments nowadays is broadly studied by environmental chemists. Atmospheric contaminants originate from various sources, have different structure, chemical and physical properties, and hence differ by time of life, toxicity, potential for accumulation in the environment and for bioaccumulation and biomagnification.
Polycyclic aromatic hydrocarbons (PAHs) are one of the common persistent organic contaminants. This group of contaminants encompasses the compounds that consist only from atoms of carbon and hydrogen and have aromatic rings of different size in the structure. PAHs high ability to accumulate in all types of environment: atmospheric air, hydrosphere (marine and surface waters), in soils and sediments, cryosphere (both ice and snow), and even worse in biosphere (from bacteria to humans). Generally long residence times in the environment make PAHs dangerous.
According to Kanu et al. (2005), persistence of PAH is determined by the half-life time and rate of decomposition; it take at least 2 years for 95% of compound to degrade. PAHs can be absorbed by human body though the skin and are proved to cause carcinogenic effects (Regulation EU 2006). Presence for a long time under the influence of PAHs also leads to allergy progress, can cause heart strikes and advance of cancer formation (Matsumura et al. 1972; Kanu et al. 2005; Schober et al. 2007; Brook et al. 2010, Kim et al. 2015).
The assessment of a long-term PAH accumulation in different types of environment belongs to a state-of-the-art research. Photochemical processes are mostly responsible for slowly transformation of PAHs to a wide range of degradation products which are even more persistent and more toxic for biota and humans (Manzetti, 2013). Estimation of short-term distribution and accumulation of parent PAHs is quite important step in the understanding of their further pathways and fate in the environment.
This project aims to quantify PAHs and assess their distribution in snow cover of mining town Barentsburg, Western Spitsbergen. Instead of considering the whole snow pack to estimate total accumulation of PAHs and their release to environment with a melt, study is focusing on upper snow cover, hence making a snapshot of the local contamination. Based on PAHs properties and individual peculiarities, taking into account local geographical settings, an attempt to appoint the sources of PAHs and their possible fate in arctic conditions is made.
Concentrations of 16 main PAHs were determined in the upper snow cover within and around Barentsburg, Western Spitsbergen. Their distribution presented a snapshot of pollution sources influence on the area and impact of local factors on rather distribution than accumulation of PAHs. It was found that:
• The main release of PAHs is occurring by the auto activity (cargo, snowmobile, ordinary autos), from non-complete coal burning at the power station and also by the non-burned coal in areas of coal storage. Generally "short-term" non- cumulative concentrations of PAH in the upper snow cover of background areas are under detection limit.
• PAHs bound with particular matter were found in much higher concentrations than dissolved ones in all sampling sites affected by the human activity. That implies that the main way of PAHs transport is particulate matter.
• Common PAH pollutants in meltwater are PHEN, NAPH and FLU. FLU and NAPH have mostly a diesel and gasoline way of origin, while PHEN can also come into the snow cover from non-complete coal combustion.
• The processes of distribution of PAHs from the power plant are defined not only by distance from the source, but atmospheric conditions as turbulence, wind strength and direction. Physical-chemical properties, such as water solubility, molar mass and photochemical reactivity in midnight sun conditions influence distribution of contaminants too.
• Although there is a difference between PAHs levels within and around settlement depending on the dominant contamination source, the uniqueness of place - mining and storing coal as well as burning the same coal at power plant make it hard to distinguish sources by applying diagnostic ratios of individual PAHs.
• Tourism is starting to impact the environment that is evident from elevated levels of PAHs along seasonal snow scooter route.
• The main role in PAHs distribution with snow in winter belongs to local meteorological conditions, at least in short-term scale.
