8.2.3 Distribution of Benzo(a)pyrene and other 

 Poly cyclic Aromatic Hydrocarbons 



YURIY L. VOLODKOVICH and OLGA L. BELYAEVA 



Institute of Global Climate and Ecology, State Committee for Hydrometeorology and Academy of Sciences, Moscow, USSR 



Introduction 



In the recent decade, the impact of various social and 

 economic factors on the environment has caused certain negative 

 consequences, including changes in the natural chemical 

 background caused by growing entrainment of pollutants in 

 natural ecosystems. Pollutants, first propagating on the land 

 and in the atmosphere, come by various routes to the world 

 oceans and, in the long run, circulate within them (Izrael & 

 Tsyban, 1989). Coastal regions rapidly accumulate pollutants 

 to critical levels producing irreversible changes in the 

 functioning of marine ecosystems. In open regions of the 

 oceans, aquatic organisms and ecosystems as a whole begin to 

 suffer from a constant impact of low intensity factors such as 

 low doses of toxicants. 



Among numerous organic pollutants causing dangerous 

 changes in the chemistry and biology of the marine environment, 

 a unique role is played by polycyclic aromatic hydrocarbons 

 (PAH's), including both the natural and anthropogenic-derived 

 materials. With a significant molecular stability as well as 

 pronounced carcinogenic and mutagenic effect, these chemicals 

 present a great danger to the existence of marine organisms. 



The most characteristic and widely spread chemical of this 

 series is benzo(a)pyrene (BaP), which is widely accepted as an 

 indicator of environmental pollution by carcinogenic PAH"s 

 (Izrael & Tsyban. 1989). 



Benzo(a)pyrene and PAH's are found in many 

 compartments of sea ecosystems from Arctic (Mallet et al.. 

 1979) to Antarctic latitudes (Clark e?fl/., 1981). Entrainment 

 of PAH's in the currents of these systems causes their further 

 circulation throughout the seas. One of the consequences of 

 these processes is accumulation of carcinogenic PAH's in 

 traditional marine products; plants and animals sold in 

 commerce (Comer, 1975; Mix et al.. 1983), which ultimately 

 threaten the health of human beings. 



There are many publications on the distribution of these 

 dangerous chemicals in hydrosystems; however, there is an 

 obvious shortage of systematic information on the patterns and 

 origins of biogeochemical cycles in the ocean ecosystems. 



This paper considers individual results from investigating 

 biogeochemical cycles in the ecosystems of the Bering and 

 Chukchi Seas. Distribution and accumulation of these toxic 

 chemicals in components of marine ecosystems (in the water, 

 surface layers, sediments, plankton, and neuston) was studied 

 using benzo(a)pyrene as a model compound for explaining 

 PAH processes in general. 



Considering that the increase in PAH's in a particular 

 marine environment depends greatly on the proximity of the 

 sources of these pollutants, it is noteworthy that there have been 

 recent increases in sources of PAH's in the southeast marginal 

 polar seas. These areas have been noted as only recently being 

 affected by any pollutants at all, which therefore makes it 

 important to study what other pollutants may also be of concern 

 in these regions. 



Investigations performed in 1988 by the research vessel 

 Akademik Korolev are a continuation of comprehensive work 

 begun in the Bering Sea basin in 1981 and 1984 (Roscigno, 

 1990). 



Methods 



Sampling 



Polycyclic aromatic hydrocarbons circulation in ecosystem 

 components of the Bering Sea and southern part of the Chukchi 

 Sea, specifically, circulation of benzo(a)pyrene, was studied 

 by the Third Joint US-USSR Bering & Chukchi Seas Expedition 

 on the Akademik Korolev in August 1988. Samples were 

 collected at 54 stations, which include four specific test polygons, 

 the North (Stations 34-37), East (Stations 1-5) and South 

 Polygons (Stations 108-1 12) in these waters. These polygons 

 are sites of continuous sampling, which were visited in 1977, 

 1981, and 1984 by scienfists from the joint US-USSR 

 expeditions. 



The goals of the sampling program were as follows; 



— collect seawater from surface to deep horizons, 

 including a near-bottom horizon; 



— collect samples of floating ice; 



— collect bottom sediments (the upper 5 cm of the 

 surface); 



— collect samples of plankton organisms taken in 

 45-100 m layers; 



— collect samples of neuston organisms taken from 

 the top 10 cm of the sea surface; and 



— continue long-term monitoring at sites occupied 

 previously in 1977. 1981, and 1984. 



Water was sampled using a Niskin water sampler, 5-101 

 per sample. Samples were obtained from 5-8 equally spaced 

 horizons from the surface to the sea floor. Surface microlayer 

 water (0.2 mm) was sampled by a stainless steel mesh (0.26 m-) 

 screen. In order to prove that the vessel was not a source of 

 contamination, some of the surface microlayer samples were 

 obtained from a tender boat at a considerable distance 



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