What is certain is that the 15 former Soviet republics are in the grip of an ecological crisis whose scale virtually defies calculation. Lakes and forests are dying. Marshes are turning into sandy wastes. Noxious gases are polluting scores of cities, and the number of terminal cancer cases is rising in industrial areas.
Much of this was known, or suspected, in the West for many years, despite Moscow's efforts to conceal such information from foreign countries and Soviet citizens. What is less well-known, perhaps, is the impact on the environment of the economic collapse endured by most former Soviet republics over the past five years.
According to a report by Georgy Golitsyn, the director of the Institute of Atmospheric Physics in Moscow, these newly independent countries face a paradox. Severe recession, reflected in falling output and use of coal, oil and industrial products, may have resulted in smaller emissions of carbon dioxide, sodium dioxide and other pollutants. But as Mr Golitsyn notes: 'Any such improvement should be recognised for what it is - an unwanted side effect of economic collapse and social hardship. No state would strive for such a result intentionally.'
In his report, published by the Radio Free Europe/Radio Liberty Research Institute, he adds: 'The catastrophic fall in living standards and the disruption of existing economic relationships throughout the CIS (Commonwealth of Independent States) cannot fail to have a negative impact on the willingness of governments to devote scarce resources to environmental protection.'
Most ecological damage is attributable to the decades-long Soviet emphasis on inefficient, filth-producing heavy industries. Communist leaders compounded the problem with a system of central planning so rigid that many factories were the sole suppliers of certain products. Thus, when the government tried to close some pharmaceutical plants in 1989 and 1990 because they were polluting the environment, it had to reopen them in order to reverse a drastic shortage of medicines.
According to J P Cole, professor of Human and Regional Geography at the University of Nottingham, the cost of cleaning up the former Soviet Union could reach an astronomical dollars 800bn ( pounds 550bn) over a 10-year period. However, as he cautioned in a paper published last December, that is a conservative estimate and covers only the cost of dealing with 'conventional' pollution. The sums needed to tackle nuclear damage could be equally high.
'That investment would actually produce very little materially except a cleaner environment,' he wrote. 'For the world as a whole the news is bad because hitherto the USSR has been seen as a net contributor to foreign assistance, on occasions a relatively generous if controversial donor of funds for development assistance. Now it has become a competitor with the Third World for such assistance from western Europe, the USA and possibly Japan.'
Mr Golitsyn, quoting Soviet data supplied to the United Nations for 1981 to 1989, says the amount of airborne pollutants dumped on Soviet territory peaked at 108 million tons in 1983 and declined to 95.5 million tons in 1989. But this fall disguised an increase in emissions of especially harmful pollutants such as nitrogen oxides, which combine with water in the atmosphere to produce acid rain. Average levels of benzopyrene, a cancer-causing hydrocarbon described by Mr Golitsyn as one of the most toxic substances known to man, were 300 per cent above the legal limit.
Despite increased public awareness of ecological problems, Mr Golitsyn says many CIS states had failed to adopt air quality standards and factories that polluted the air often received token fines. 'The regulatory process is rife with corruption . . . The only real hope for short-term improvement of air quality in the CIS is continued industrial malaise. If production stabilises, one may expect further deterioration.'
Water pollution has reached crisis proportions in Kazakhstan and Central Asia, where the misuse of pesticides, defoliants and fertilisers, and irresponsible irrigation projects have virtually killed the Aral Sea. Its level is falling by about 1 metre (3ft) every year, and the contamination of water supplies has caused a sharp increase in infant mortality.
Siberia's Lake Baikal, the largest fresh water lake in the world, is threatened by a big pulp and paper mill emitting various sulphates and chlorides. Even more alarming is the crisis in Lake Ladoga, Europe's largest lake near St Petersburg, in which levels of phosphorus have risen by 300 per cent over the past 30 years and those of nitrogen by 30 per cent.
Mr Golitsyn believes that 'the water supply of the 5 million residents of St Petersburg is now in jeopardy'. He adds that many other lakes and reservoirs are so polluted that they are infested with oxygen-sucking plants that kill off animal life.
Meanwhile, pollution and overgrazing of pastures have caused a steady expansion of deserts. In both Dagestan and the Kalmyk republic near the Caspian Sea, sand covered 15,000 hectares of pasture in 1954 but 1 million hectares in 1990. In the Arctic tundra, mining, prospecting and overgrazing of reindeer herds have caused the disappearance of 40 million hectares of pasture - an area bigger than Germany.
'The success of economically painful steps to protect the environment will depend on public understanding and acceptance of the urgent need to tackle environmental problems in the CIS,' Mr Golitsyn says. 'But to turn such principles into concrete realities will require major changes in the way people brought up under the Soviet system think about the economy and the environment.'