Acid rain: definition, causes and consequences

Definition of acid rain

According to the Dictionary of the Spanish language of the Royal Spanish Academy, to which we can go to answer what acid rain is and, in fact, it is the best option to know its strict definition, the definition of acid rain is “precipitation in the atmosphere from industrial emissions of acid pollutants ” . Thus, it can be defined as the mixture of rainwater with environmental pollution or air pollution. It is an atmospheric phenomenon that poses serious problems for the planet, both for all of nature and for the artificial infrastructures built by man. Do you want to know better why this is the case? We will explain it to you below.

Main causes of acid rain

As we have already mentioned, the causes of acid rain are directly related to environmental pollution , we could say that the direct causes are human activities through factories, heating, power plants, vehicles , etc., which burn derivatives oil with sulfur and they also burn coal.

Now that we have clarified what acid rain is as well as the main causes of acid rain , there are more aspects to deal with to better understand this environmental problem. What specifically produces acid rain? What are its components? and how is it formed? These are common doubts about this atmospheric phenomenon, since to find solutions it is necessary to know well the origin of the problem. Keep in mind that rain contains carbon dioxide, as well as any other form of environmental water such as snow, ice or fog. This makes this water a bit acidic in itself, over a pH of 5.6, but acid rain has a pH of 5 , and can reach a pH of 3 when it is very acidic.

The acid rain is formed when the water in the air, is moisture contact and mixed with nitrogen oxides, sulfur dioxide and sulfur trioxide . These are gases that together with water produce sulfuric acid, sulfurous acid and nitric acid, causing the rain to become more acidic than it already is and, when falling, damage the environment in which it is found.

After knowing the definition of acid rain, its causes, its formation process, only one detail remains to be clarified to better understand this problem before addressing the effects and consequences of acid rain on the environment and for people. It is about knowing exactly the basic components of this rain, which allows its better understanding and that it is somewhat easier to think of solutions.

The formulas of the primary components of acid rain , that is, its precursors, are as follows:

• Environmental humidity water: H2O
• Nitrogen oxides: NOx
• Sulfur dioxide: SO2
• Sulfur trioxide SO3

The formulas of the acids resulting from the previous mixture that acidify the humidity forming the acid rain itself are the following:

• Sulfuric acid: H2SO4
• Sulfurous acid: H2SO3
• Nitric acid: HNO3

When combined with environmental humidity, these substances precipitate in the form of acid rain, falling on the earth, water, forests, buildings, etc., damaging everything due to its acidity. Therefore, acid rain deteriorates the environment .

In addition, the pollutants that are expelled by the burning of petroleum derivatives with sulfur, coal, etc., not only pollute the air and humidity of the area in which they are created, but can also travel long distances by the wind , up to thousands of kilometers, before combining with humidity, turning into acids and falling in the form of precipitation, be it rain itself or snow, hail, fog, and so on. This means that pollution can be created in one part of the world, but acid rain from that pollution can precipitate in another part of the Earth.

Among the effects and consequences of acid rain we find the following:

• Acidification of terrestrial waters, such as rivers, lakes, seas and oceans. Therefore, serious damage to aquatic and terrestrial life, by not being able to drink from these waters or feed on the fish and other animals that inhabit them.
• Significant damage to vegetation, forest areas, jungle areas, etc., directly and indirectly. This acidified atmospheric phenomenon contains protons that cause some ions to fall into contact with the earth, for example lead, zinc, calcium, iron or aluminum, and this impoverishes the soil, causing it to lose nutrients. The direct consequence of this is that vegetables suffer stress and nutrient deficiencies that make them sick, more vulnerable to contracting pests and even dying. Where this happens, there is less vegetation, less habitat and food for animals and people.
• It kills the life of nitrogen-fixing microorganisms, that is, they reduce the ambient nitrogen.
• Acidified rain damages and deteriorates the surface of materials, that is, it has a corrosive effect on materials such as wood, stone and plastic, among others. For example, many buildings, monuments and statues have been affected by the corroding of the marble or limestone that constitutes them, since the acids from these precipitations can dissolve the calcium carbonate, which is part of the materials of these constructions.
• The acids that contain sulfate in these precipitations cause an increase of the greenhouse effect. Although there may be small amounts of sulfate, these when in contact with certain components present in swampy areas, increasing the production of methane gas carried out by methanogens, the microorganisms that produce them naturally.

In summary, acid rain impoverishes soils, plants and waters, damages aquatic, terrestrial and aerial life and is related to the greenhouse effect .

After knowing what it is, the causes and consequences of acid rain, we are left to think about the solutions. ¿ What steps can be taken to reduce acid rain ? This is a question that we have been asking ourselves since the 1980s, when there began to be awareness about this issue and solutions were sought through treaties and laws with the aim of reducing pollution and, therefore, the acidity of rainfall and other environmental problems.

These are some solutions that provide answers to how to reduce the impact and how to avoid acid rain , focusing above all on reducing the emissions of the pollutants that cause the problem:

• Reduce sulfur and nitrogen levels to the maximum in emissions from factories, heating systems, vehicles, etc., using new technologies that help control these emissions and using renewable energies more and more.
• Promote the use of private, commercial, government and public transport vehicles with natural gas, electric systems and other alternative options.
• Installing a three-way catalytic converter in vehicles, which helps reduce harmful emissions.
• Reduce electricity consumption in the home, for example not leaving lights on or not using heaters.
• Reduce the use of chemicals in crops.
• Add alkaline compounds to ponds, lakes and rivers to balance the pH.
• Plant trees.
• Promote education around environmental problems and their causes, consequences and solutions.