Relative contributions of sulfuric and nitric acids in acid rain to the acidification of the ecosystem: implications for control strategies
Much of northeastern North America has been receiving precipitation of pH 4.6 or less, i.e. more than ten times more acid than normal rain (pH = 5.6) for at least the past 20 to 30 years. Originally, this acidity was almost totally due to sulfuric acid. These inputs of sulfuric acid in the very acid sensitive Adirondacks may have removed much of the neutralizing and nitrate-utilizing ability of the soils and water. Thus, this area may now be more sensitive to atmospheric inputs of nitric acid. Further work is required on the impact of acid nitrate deposition on the ecosystem but with equal certainty it can be stated that sulfur deposition remains the princpial long term threat to acid sensitive ecosystems. It can be concluded that: much of the nitric acid in acid rain is decomposed in the soils and waterway, and is not a significant contributor to long-term acidification of soils and waters; although in the long term, nitric acid in atmospheric deposition is not likely to be contributing to the overall acidification of the environment, during the spring thaw, in areas which have been heavily impacted by acid rain for a number of years, nitric acid which has concentrated in the snow pack over the winter may cause ecological damage, especially to fish populations; though there is little doubt that tighter control strategies are necessary to diminish the effects of acid rain on remote ecosystems the existing control strategies, which have put more emphasis on the control of emissions of sulfur oxides than nitrogen oxides, have a reasonable scientific basis given our present limited knowledge of their effects on the ecosystem.
- Research Organization:
- Domtar Research Centre, Senneville, Quebec
- OSTI ID:
- 7019351
- Journal Information:
- J. Air Pollut. Control Assoc.; (United States), Vol. 31:11
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ACID RAIN
CHEMICAL COMPOSITION
AQUATIC ECOSYSTEMS
ACIDIFICATION
NITRIC ACID
ENVIRONMENTAL IMPACTS
POLLUTION CONTROL
SULFURIC ACID
TERRESTRIAL ECOSYSTEMS
BIOLOGICAL EFFECTS
DECOMPOSITION
ECOLOGICAL CONCENTRATION
SEASONAL VARIATIONS
SNOW
WASHOUT
ATMOSPHERIC PRECIPITATIONS
CHEMICAL REACTIONS
CONTROL
ECOSYSTEMS
HYDROGEN COMPOUNDS
INORGANIC ACIDS
PRECIPITATION SCAVENGING
RAIN
SEPARATION PROCESSES
VARIATIONS
500200* - Environment
Atmospheric- Chemicals Monitoring & Transport- (-1989)
510200 - Environment
Terrestrial- Chemicals Monitoring & Transport- (-1989)
520200 - Environment
Aquatic- Chemicals Monitoring & Transport- (-1989)