What Is Acid Rain? How Does It Affect Humans and the Environment?

Acid rain generally refers to any kind of precipitation with higher-than-normal levels of acid.

Acid Rain

Acid rain may contain acidic components, such as nitric or sulfuric acid, that hit the ground from the atmosphere. It may come in either dry or wet forms, such as rain, fog, snow, hail, or dust.

This type of precipitation may not be heard as much as it was in the past. Across the United States, the 1990 Clean Air Act Amendments aided in lowering pollutant levels, which led to more acidic rain. However, acid rain still falls in different areas of the world.

When it comes to the pH scale, a pH that is under 7, which is the neutral level, indicates that a substance or component is acidic. On the other hand, a pH that exceeds seven indicates alkalinity or that the substance is basic.

In most cases, rain is minimally acidic, with a pH level of roughly 5.6. However, for acid rain, the pH may range from 4.2 to 4.4, which is roughly the same as that of tomato juice.

Acid rain may result when oxygen and water in normal precipitation combine with chemicals, such as nitrogen oxides and sulfur dioxide. Such chemical reactions make normal rain more acidic.

When the particles get released into the atmosphere, air and wind currents end up sweeping them. Such particles then combine with oxygen, water, and other types of chemicals to create nitric and sulfuric acids. Such acids typically combine with water and hit the ground as precipitation. At times, when moisture is not sufficient, the particles hit the ground and land on different surfaces, such as buildings, plants, trees, and bodies of water.

How Acid Rain Affects Humans and the Environment

Human Health

Acid rain can pose health risks. However, the danger of acid rain does not come from getting wet from raindrops or swimming in waters with acid rain. Rather, the risks come with inhaling particles from the precipitation.

When a person gets exposed to high levels of sulfuric and nitric acid, especially as time passes, different problems could result. These may include lung fluids, dental erosion, or irritations in the skin, eyes, and mucous membranes.

The particles of nitrate and sulfate that lead to acidity in the rain can also lead to or worsen cardiovascular issues, respiratory illness, lung cancer, or a lower birth weight.

Animal and Environmental Health

The effects of acid rain also extend beyond human health to affect animals and the general environment. As for animals, the most affected ones are those that dwell in aquatic settings, such as rivers and lakes. Though not all animals are sensitive to the level of acidity, there are some creatures, such as snails and clams, that need a pH level of at least 6 for survival. Moreover, several young species do not manage acidity the same way adults do.

Acid rain can also lead to food chain disruptions. For instance, though frogs can live at pH levels that go as low as 4, the mayflies they prey on may not survive below a pH level of 5.5. This could lead to cascading impacts, as species that may survive at such acidity levels could still suffer from starvation.

Acid rain can also impact bodies of water, buildings, plants, and forests in different ways. For one, it can boost the dangers of bodies of water. It absorbs aluminum from the soil that surrounds it when it hits the ground and enters the soil. This then enters streams and lakes and could result in water toxicity, posing danger to the creatures that live in such waters.

As for buildings, acid rain chemicals may also break down metal and stone on structures. They may also fade finishes and wear down surfaces.

Acid rain can also lead to the destruction of nutrients necessary for tree health. It expels aluminum, making it harder for trees to source water from the ground. Trees that are situated at higher altitudes are also more prone to acidic fog and clouds.