The United States Environmental Protection Agency defined: “Acid rain is rain that has become acidic due to certain pollutants in the air. Acid rain is a type of acidic deposition that can appear in many forms. The term wet deposition refers to rain, snow, sleet or fog, whose acidity is much higher than normal”. Robert Angus Smith discovered this phenomenon while investigating the chemistry of air in British industries in 1850.
It is caused by various pollutants released into the air. Firstly, we find human activities: the burning of fuels in industry, power plants, emissions of nitrogen oxides due to gases produced by motor vehicles and intensive livestock farming that produce ammonia from the decomposition of organic matter. These three pollutants can travel long distances from their original sources and oxidize in the atmosphere, generating nitric acid and sulfuric acid.
The “acidification of the environment” occurs when rain, combined with the mentioned acids, changes its pH and, upon falling on the soil and in the waters, alters the chemical characteristics of these elements, endangering the ecosystem.
The consequences can be devastating. Fish begin to die, groundwater becomes contaminated, affecting agriculture and making it unsuitable for human consumption.
Oceans are also affected, losing biodiversity and productivity as the pH drops and harms phytoplankton, a food source for various organisms and animals, leading to the extinction of different marine species. Acid rains damage forests. The concentration of metals in the soil and its low pH prevent the vegetation from absorbing water and nutrients adequately, which damages the roots, reduces growth and makes the plants weaker and more susceptible to diseases and pests.
Impact on Soil, Water and Air
- Soil. Acid rain can modify the pH of the soil, making it more acidic. This affects the availability of nutrients to plants, as well as the structure of the soil, reducing its ability to retain water and essential nutrients. Acid rain can have a devastating impact on flora and fauna. Plants are sensitive to changes in soil pH and can experience damage to their leaves, stems and roots, reducing their ability to grow and reproduce.
- Waters. Bodies of water such as rivers, lakes, and streams can become too acidic to support aquatic life. This threatens the survival of fish, amphibians, invertebrates and aquatic plants, which disturbs aquatic ecosystems as a whole. On the other hand, aquatic organisms directly suffer the effects of water acidification, which can cause the decline of populations and the local extinction of species.
- Air. In addition to directly affecting soil and water, acid rain also contributes to air pollution, which can have detrimental effects on human and animal health. These compounds can irritate the airways and aggravate pre-existing medical conditions such as asthma.
Challenges to be met
The United States Environmental Protection Agency recommended different ways to prevent acid rain. Local, national, and international levels require coordinated action. We can generate electricity without using fossil fuels, that is, replace it with solar or wind energy since they produce much less pollution. Turning off lights, electrical appliances, and computers when they are not in use can achieve savings in our daily life.
Another way to reduce such rains involves car manufacturers reducing the level of nitrogen oxides and other pollutants emitted by new vehicles. The use of alternative fuels such as natural gas is recommended. Factories must filter and purify water before releasing it back into rivers to prevent changes in pH and contamination with acids and metals, which is crucial.
It is imperative to raise awareness about acid rain as it is essential to promote understanding and action against this environmental issue. Increasing public awareness of the negative effects of acid rain can generate behavior changes and policies to reduce pollutant emissions and mitigate its impacts.
In conclusion, acid rain is a serious environmental problem that requires urgent attention and effective mitigation measures to protect the environment, human health, wildlife, soils, water bodies and structures.
