When rain clouds form, they’re not always made up of pure water; in some cases, a chemical reaction takes place, with compounds such as sulfur dioxide and nitrogen oxide that are released into the air. These gases can rise high into the atmosphere, and when they mix and react with the water and oxygen, they fall to the earth as what we know as acid rain. How bad are these polluted rain showers? That’s what we’ll be exploring today, in this episode of The Infographics Show: What Does Acid Rain Do To Your Body?
Ok, so before we get in to the effects of acid rain on the body, let’s first look at what acid rain is and why it forms. While some acid rain is natural, with the gases leaking into the atmosphere from volcanoes, the majority of the gas comes from human activity. The major sources of sulfur dioxide and nitrogen oxide that we find in the atmosphere come from the following: burning of fossil fuels to generate electricity, with two thirds of sulfur dioxide and one fourth of nitrogen oxide in the atmosphere coming from electric power generators; The emissions from vehicles and heavy equipment; and manufacturing, oil refineries and other industries. Once these gases are in the air, the wind can blow them great distances, making acid rain a problem for everyone, and not just those who live close to these sources.
The acidity of the rain is measured by using the traditional pH scale, where 7.0 is neutral, above 7 is alkaline, and below 7 is considered acidic. Normal rain has a pH of about 5.6, so it is naturally slightly acidic, which is due to the carbon dioxide that’s dissolved in it. But acid rain has a pH between 4.2 and 4.4, so it’s much further down the scale. Policymakers, research scientists, and ecologists rely on the National Atmospheric Deposition Program, or NADP’s, National Trends Network for measurements of acid rain. They collect acid rain at more than 250 monitoring sites throughout the contiguous US, Canada, Alaska, Hawaii and the US Virgin Islands, so they can assess the effects.
So how bad is this acid rain? Actually, the wet acid rain that falls to the ground, making up our rivers and lakes, is not dangerous. Even swimming in a lake affected by acid rain, is no more dangerous for a person, than walking in normal rain or swimming in non-acidic lakes. There is also another process in the formation of acid rain, known as dry deposition. Dry deposition happens when the wind blows acidic particles and gases from the atmosphere, onto buildings, cars, homes, and trees. Then when it rains, the runoff water adds those additional acid particles to the acid rain, making the combination more acidic than the falling rain alone.
But again, even with this higher acidity level rain, we couldn’t find information that says it’s a particular danger to humans. However, when the pollutants that cause acid rain are in the air, they can be harmful to humans, and in areas where dry deposition occurs, there’s a high likelihood that these gases can be breathed in. Sulfur Dioxide reacts with the atmosphere to form fine sulfate and nitrate particles, which may be inhaled into people’s lungs. According to the Penn State College of Earth and Mineral Sciences, there have been many scientific studies that have identified a relationship between elevated levels of fine particles and increased illness and premature death from heart and lung disorders, such as asthma and bronchitis.
What about effects on other parts of our environment? Is this something we should be concerned about? According to the EPA, the ecological effects of acid rain are most clearly seen in aquatic environments, such as rivers, streams and lakes, where the lower pH water can be harmful to fish and other wildlife. As the acidic water flows through the soil, it draws aluminum from clay particles, which then flow into the rivers, streams and lakes. Some types of plants and animals can tolerate acidic waters and moderate amounts of aluminum, but the ecosystem is affected.
At pH 5, most fish eggs cannot hatch and at lower pH levels, some adult fish die. In extreme cases, acidic lakes have no fish life at all, and even if a species of fish or animal can tolerate the acidic water, the animals or plants it eats might not be able to, and when they are killed off, the food chain is affected. For example, frogs have a critical pH around 4, but the mayflies they eat are more sensitive and may not survive a pH level below 5.5, so the frog’s food source disappears and eventually the frogs do as well. Acid rain can also affect plants and trees. Dead or dying trees are a common sight in areas affected by acid rain. The aluminum that we mentioned can also be harmful to plants, and the acid rain also removes minerals and nutrients from the soil that the trees need to grow.
Dry deposition of acidic particles can also have a corrosive effect on the buildings, cars, and homes that they end up on. The acidic deposits can damage metals, such as bronze, which many statues are made of, as well as deteriorate paintwork and stone, such as marble and limestone. These effects can reduce the value of buildings, bridges, cultural objects, such as statues, monuments, and tombstones, as well as cause damage to our homes and vehicles.
So swimming in a lake that’s considered acidic may not be risky, but then if something harms one part of an ecosystem, a species of plant or animal, it can have an impact on everything else. And if you have a valuable bronze statue, it’s certainly worth keeping it regularly cleaned so it’s not destroyed by the acid rain. Have you experienced any effects from acid rain? Let us know in the comments! Also, be sure to check out our other video called What If You Fell Into Acid?! Thanks for watching, and, as always, don’t forget to like, share, and subscribe. See you next time!