Acid rain is a term that refers to a mixture of wet and dry deposits (deposited material) from the atmosphere that contains greater than normal amounts of nitric and sulfuric acids. The precursors, or chemical precursors, to the formation of acid rain result from both natural sources, such as volcanoes and decaying vegetation, and man-made sources, with emissions of sulfur dioxide (SO2) and nitrogen oxides (NOx) primarily resulting from the combustion of fossil fuels.
Acid rain occurs when these gases in the atmosphere react with water, oxygen, and other chemicals to form acidic compounds. The result is a bland solution to sulfuric acid and nitric acid, from power plants and other sources, the prevailing winds blow these connections across state and national lines, sometimes hundreds of miles. The lower the pH of a substance, the more acidic it is.
Acid rain causes acidification of lakes and streams and contributes to tree damage at elevations (eg, red spruce above 2,000 feet) and many sensitive forest soils. In addition, acid rain accelerates the deterioration of building materials and paintings, including irreplaceable buildings, statues, and sculptures that are of cultural importance. Acid rain and dry deposits of acid particles contribute to the corrosion of metals (such as bronze) and the deterioration of paint and stone (such as marble and limestone). These effects significantly reduce the social value of buildings, bridges, cultural objects (such as statues, monuments, and tombstones), and vehicles.
Before they fall to earth, the gases sulfur dioxide (SO2) and nitrogen oxides (NOx) and the particles they produce – sulfates and nitrates – contribute to reduced visibility and are harmful to public health. The ecological effects of acid rain are most clearly seen in aquatic or aquatic environments such as streams, lakes, and swamps. Most lakes and streams have a pH between 6 and 8, although some lakes are of course acid, even without the effects of acid rain.
Of course, acid rain is not the only cause of these conditions. Other factors contribute to the total pressure in these areas, including air pollutants, insects, disease, drought, or very cold weather. Indeed, in most cases, the effects of acid rain on trees are due to the combined effects of acid rain and other environmental stressors.
Sulfates and nitrates, that form in the atmosphere from emissions of sulfur dioxide (SO2) and nitrogen oxides, add to reduced visibility, meaning we can’t see through the air clearly. Pollutants that cause acid rain – sulfur dioxide (SO2) and nitrogen oxides (NOx) – are harmful to human health.
Many scientific studies have found a link between increased particulate matter levels and increased disease and premature death from heart and lung diseases such as asthma and bronchitis.