New concerns on acid rain stretch from southeast US to USSR
Damage to woodlands in some areas of the Southeastern US have a Munich connection this week as 31 nations, including the Soviet Union, gather to discuss international strategies against acid rain pollution.
Acid rain is the prime suspect in the new reports of tree damage in certain parts of the Southeastern United States. But given the US position that not enough is known about the effects of acid rain to justify major public expenditures to clean it up, it is unlikely the US will commit itself to any specific cleanup plan.
Environmentalists in the US, however, contend that enough is known to act now - although so far, efforts to pass federal cleanup legislation have failed.
(At the opening of the four-day Munich conference on air pollution, the Soviet Union, signaling readiness to cooperate with the West, said Monday it would cut its noxious emissions 30 percent by 1993, Reuters reported.
(While some Western nations have taken initial steps to lower pollution, Western experts say the Soviet bloc has so far only given low priority to environment questions, the report said.
(Chief Soviet delegate Yuri Izrael told the ministerial session: ''The Soviet Union declares its will and determination to implement practical measures to reduce its emissions by 30 percent by 1993.'' He said the Soviet Union was giving priority to environmental protection, spending $9.6 billion a year on the effort.)
The concern about acid rain is growing around the world: A survey last year showed that one-third of West Germany's forests are in some stage of decline.
Recently, US environmental groups have pointed to signs that acid rain is damaging trees, aquatic life and crops in the Southeast, not just the Northeast.
But two of the prime researchers of Southeastern forests recently cautioned members of a congressional panel that their findings do not prove that acid rain is to blame for recorded declines in tree growth. All they would say is that their research does ''strengthen the hypothesis'' that air pollutants, such as ozone, sulfur dioxide, toxic metals, or acid rain, may be among the culprits of red spruce decline.
As for the German forest decline, the two researchers, Robert Bruck and Ellis Cowling, said several hypotheses in addition to acid rain have been proposed as the cause. Among them: gaseous pollutants, magnesium deficiency caused by atmospheric deposition, and stress from a combination of pollutants and drought.
Decline at all elevations is a ''rapidly developing'' pattern, not only in Germany but in many parts of Central and Eastern Europe, the researchers said.
In North Carolina, the two men have found red spruce at elevations above 6, 350 feet losing 75 to 90 percent of their needles. Drought has been eliminated as a cause, they say. At lower elevations, however, they found that the red spruce appear healthy. Trees at the higher elevations may be suffering from exposure to concentrated cloud moisture, says Dr. Cowling.
In its recent joint report on acid rain in the south, the National Clean Air Coalition and the Friends of the Earth Foundation said that rainfall over much of 13 Southeastern states averages 10 to 20 times more acidic than normal. The report points to coal-fired power plants, other industries, and automobiles as the main sources of acid rain nationally.
''No longer can the South afford to believe that acid rain is only a Northeastern problem,'' the report said.
But neither can the South blame the entire issue on the rest of the country. For example, the report said that 13 southern states produce nearly one-third of the total US emissions of sulfur dioxide, one of the main forms of pollution associated with acid rain. (Another is nitrogen oxide.)
But the report tied the red spruce decline to acid rain - something the researchers of the red spruce have not done. The report endorses the National Academy of Science's call for a 50 percent reduction in acid deposition. Polluters could be required to use specific equipment or to meet a specific emissions reduction target, the report said.
A federal task force, meanwhile, is studying the causes and effects of acid rain. ''Many scientific uncertainties remain, while the demands for definitive answers mount,'' the task force said in its last report to the President and Congress.
The utility industry, like the Reagan administration, endorses further study of the possible causes and effects of acid rain. But Robert Beck, manager of environmental programs for the Edison Electric Institute, a trade organization, says power plants are continuing to reduce their sulfur-dioxide emissions.
About 20 percent of the nation's power plants have ''scrubbers,'' antipollution equipment to reduce such emissions, he said. Federal law requires that all plants built since 1977 have such equipment. Some states require older plants to have them as well.