Acid rain is a growing environmental problem that is effecting a large part of North America. Acid rain can be extremely harmful to lakes, streams, forests, plants, and animals inside of these ecosystems Epa.Gov.

What is Acid Rain?

Acid rain is a combination of wet and dry deposited material in the atmosphere that contains harmful amounts of nitric and sulfuric acids. These chemicals can be released into the atmosphere naturally by volcanos and decaying vegetation. There are non natural ways that us humans contribute to acid rain too, such as emissions of sulfuric acid and nitrogen oxide that are a negative result of fossil fuel combustion. In our country almost 2/3 of sulfur dioxide, and almost 1/4 of nitrogen oxide come from the burning of fossil fuels such as coal. [1]

The Science

When Sulfuric acid and Nitrogen oxide react with oxygen and water, they come to form different types of acids that contain “a mild solution of sulfuric acid and nitric acid”.[2]

There are two types of acid rain, a wet deposition, and also a dry form. Wet deposition is when the acidic chemicals are mixed with the snow, rain, fog, or mist in the sky, and fall to the ground in a wet mixture. The damage done ranges from the acidity of the water, and the plants and animals in that ecosystem that rely on the water. Acidic rain has the biggest impact on the trees at high elevations in forests, because they absorb most of the rainfall. This could have an immense negative impact on the ecosystem, clearly showing how dangerous acidic rain is..[3]

Dry deposition occurs when the chemicals in the air fall to the ground mixed with smoke or dust. They then later stick to tress, the ground, and basically everything they come in contact with. These acids are later washed off by rain, leading to a greater acidic mixture. “About half of the acidity in the atmosphere falls back to earth through dry deposition.”[4] Thus creating great dangers to the earth.

The Effects on Ecosystems

The effect of acidic rain are most easily seen in the aquatic, or streams and lakes. Most of the water environments have a ph level of 6-8, some lakes are naturally acidic, but the acid rain primarily impacts the sensitive waters that are not capable of getting rid of the acidity themselves. The soil inside of the waters have a buffering capacity, this is the process of neutralizing the acidic compounds. Waters located in watersheds only have limited amount of buffering capacity. “In areas where buffering capacity is low, acid rain releases aluminum from soils into lakes and streams; aluminum is highly toxic to many species of aquatic organisms“.

Here is a ph scale that shows the ph levels of common goods.

When this occurs, fish and aquatic organisms are directly harmed. “ Acid rain causes a cascade of effects that harm or kill individual fish, reduce fish population numbers, completely eliminate fish species from a waterbody, and decrease biodiversity“. As the aluminum in the soil is released due to the acidity levels of the water, the acidity rises and so do the levels of aluminum, both are toxic to fish and aquatic organisms.[5] Low levels of ph due to acidity, and high levels of aluminum may not kill all of the fish, but cause chronic street to the rest, which “leads to lower body weight and smaller size and makes fish less able to compete for food and habitat”.

Some plants and animals are able to live in acidic conditions, but not all, most are sensitive to the acid levels, and will die due to the low levels of ph. The younger the species are the more vulnerable they are to the acid. If the ph level of the water is 5 or below, fish eggs cannot hatch.[6]

This cart shows the different types of species that can tolerate different ph levels. There is a direct correlation between lower ph levels, and the deaths of species in different types of waters.

Ecosystems can be greatly effected by acidic rain even though some species can tolerate lower ph levels. Because all the organisms in an eco system are interconnected, when the ph levels of water decrease, and the aluminum levels increase certain species die, which are the food supply of other species in the ecosystem.[7] This shows that acidic rain has a direct negative impact on ecosystems.

In conclusion, i have stated the many ways that acidic rain can harmfully effect, and possess a danger to ecosystems. In the near future, we will have to address this problem before it gets out of hand. The EPA (Environmental Protection Agency) has started a program called the Acid Rain Program, where it tries to stop the levels of ph from decreasing in waters in America.[8]