POLLUTION IN THE CONDITIONS OF THIS WAR DANGER OF AN ECOLOGICAL CATASTROPHE

Professor Predrag Polic
Faculty of Chemistry, University of Belgrade

Polluting substances endanger the population directly through several mediums: air, water and food, but one should not neglect the indirect influence stemming from the chemical transformation of pollutants (which can result in the increase or in the reduction of their toxicity), as well as from the fact that they tend to accumulate (most often in geological formations or in the biosphere). Because of NATO’s military actions in Yugoslavia the most acute problem is air pollution, in view of the fact that the pollutants spread quickly through the air, that it is impossible to protect the population swiftly and efficiently and because it largely depends on the weather. For example: Belgrade would have experienced a major ecological disaster on April 18 this year, had the wind been blowing from the east-northeast. All the toxic substances from the Pancevo industrial zone (phosgene, vinyl-chloride), harmful and poisonous products of burning fuel, but also many other substances, would have been blown right into Belgrade. Luckyly, the wind was westerly, at times strong, and rain also helped in the reduction of air pollution (including phosgene hydrolysis, yielding carbon dioxide and hydrochloric acid). However, it is almost impossible to evaluate the qualitative and quantitative aspects of downwind pollution because of rinsing (and pollution of soil, water and plant life), as well as because of indirect influences caused by chloridisation and other chemical reactions. The next day, which was sunny, certainly contributed to various photochemical reactions, especially in higher layers of the atmosphere, and the spreading of toxic substances towards the east was certainly not limited only to Serbia’s territory. The wind blowing from the west definitelly would not be an “ally” of the capital in the event of a hydrofluoric acid emission from Baric, especially if the fact is taken into consideration that gas-masks provide no protection against this toxic substance. With pollution which results from the burning of fuel one should primarily pay attention to the products of incomplete combustion the highly toxic carbon monoxide, aldehydes (which take part in photochemical reactions), soot (which adsorbs extremely dangerous polycyclic aromatic hydrocarbons) and other substances. Heavy metals are also extremely dangerous, such as mercury which in its methylated form (the most toxic) can be transported for thousands of miles. One should also not rule out the possibility of the use of defoliants, used in the Vietnam war, such as “dioxine” (2,3,7,8-tetrachloro-dibenzo-p-dioxine), both in phase one (air raids) and in the event of a ground intervention. When we consider the radioactive pollution of the air and the use of 30mm anti-armour ammunition made with so-called depleted uranium, which is flammable and upon impact turns into a quite mobile aerosol, besides alpha radiation, we must not forget the chemical toxic qualities of uranium. One should probably not even mention the consequences of the eventual targeting of nuclear facilities at the “Vinca” institute, but this pollution would certainly spread into all spheres air, water, soil and the biosphere.

Water pollution is a less acute, but not a potentially less dangerous problem. One should certainly not underestimate the pollution of rivers with oil and its derivatives, as well as the potential pollution with acids, alkalies, ohenoles and suchlike. But oil flows away, acids and alkalies are quickly diluted, phenoles hydrolise, etc. The pollution of underground waters is much more dangerous, since they have a very limited capacity for self-purification (this is why “Makis“ and many other wells are in great danger, because pollutants reach underground waters both from the surface and by infiltarting through the bank sediments of polluted rivers). It should also be remembered that rivers, although they flow, are being self-purified by their bottom sediments, therefore toxic substances accumulate and, if not degraded, can be released (mobilised) again if there is a change in the physical and chemical properties of the water ionic forces, pH, redox potentials, the presence of complexing agents (including natural ones humic substances, which can increase or reduce both the mobility and the toxicity of polluting substances). Artificial accumulations on large rivers are in special danger because the process of sedimentation is increased due to the slowing down of the flow of the river this is especially related to the Djerdap accumulations. It is a fact that here also, just like in the case of air pollution, state boundaries do not exist a dramatic pollution of practically any river in Serbia will almost certainly affect (in several days, months or years) the neighbouring “downstream” countries.

Technological backwordness of our industry (and infrastructure as a whole) will inflict catastrophic consequences to both underground and surface waters. Namely, the use of polychlorinated biphenyles (PCB) in transformer stations (cancer inducing substances which were banned in the world decades ago) means that destroying any transformer station, whether it is a part of an energy producing section in some of the already destroyed oil refineries, a transformer station in any industrial plant, or in the transmitting tower at Mt. Avala, will cause a spill of these substances, and it is a known fact that one litre of pyralene (PCB) pollutes one billion litres of water. One should also bear in mind that even in those facilities where pyralene was replaced by permitted liquids, the PCB was, in most cases, not destroyed (neutralised) but only stored somewhere in the factory yard, where the barrels are again exposed to potential destruction.

Finally, the consequences of the chemical pollution of food is most easy to control, therefore the danger to the population in this case is greatly reduced, especially if we speak about final products. However, agricultural products can be contaminated by polluted water, atmosphere precipitation and by all the toxic substances mentioned above.