Air pollution has an effect on Earth in subtle and major ways. Consequently on the plants and animals depending on air and the earth for life. We all need to be concerned about air quality in our lives. There are things we can do to improve our supply of fresh air that will help not only our lives but also the lives of people around the world.
The main effects of air pollution on the earth’s environment include acid deposition; eutrophication; smog; ozone loss; and climate change. Each of these air pollution effects is extremely complex. Here you will find a brief introduction to them.
Acid deposition is the addition of excessive amounts of acid to the environment through airborne mechanisms. Acid rain is the best known form of this effect, but acid may also be deposited in the forms of snow, fog, gas, and dust. Acid air pollution forms mainly during fossil fuel combustion. When combustion emissions of sulfur dioxide and nitrogen oxides meet water in the air, they form sulfuric acid and nitric acid, respectively. When acid air pollution falls upon plants, surface waters, and soils, it has a number of effects.
Acid oxidizes many nutrients and essential trace metals, making them unavailable to life forms. Aluminum has an inhibitory effect on nutrient uptake by plants, and high concentrations of aluminum are one of the primary causes of forest decay. Metals dissolved in water by acids can be highly toxic as well. Acid-dissolved mercury is dispersed through waters to be taken up the food chain, resulting in high concentrations of mercury in predatory fish and shellfish eaten by humans. Acid-dissolved metals may include lead, cadmium, arsenic, phosphorus, and others, all of which can harm human and animal health.
Buildings and roadways can be eroded by acid deposition. Sulfur dioxide breaks down limestone by reacting with calcium carbonate in the stone, causing the limestone to absorb water. The limestone will later crumble and fall.
Eutrophication is caused by an increase in plant nutrient availability in water. Acid-dissolved phosphorus, ammonia, and nitrogen act as a fertilizer, accelerating the growth of algae, duckwee, and other floating water plants. The abundant plant life blocks sunlight from penetrating water. Decomposing plant matter consumes most of the oxygen available in water, suffocating fish and other animal aquatic life.
Smog is a word derived from “smoke” and “fog”. Smog is divided into two seasonal categories.
Summer smog, also called photochemical smog, mainly consists of ozone, an oxidizing agent just like acid. It is visible as a brown haze. Ozone forms when ultraviolet light from sunshine splits nitrogen dioxide (NO2) into nitrous oxide (NO) and oxygen (O). The lone oxygen atom then combines with a two-atom oxygen molecule to form the three-atom molecule, ozone (O3). Summer smog is most intense under conditions of relatively high summer temperatures; long hours of sunlight; and still air that traps photochemical air pollution. Summer smog causes eye irritation and respiratory distress. Active children inhale larger amounts of summer smog and suffer its effects more. The elderly and people with respiratory diseases are also especially vulnerable to summer smog.
Winter smog is also called acid smog. It forms when ground-level temperatures are lower than upper-air temperatures, because then ground-level air does not rise and disperse the air pollutants emitted near the ground. This condition is called temperature inversion, because normally upper-level air is cooler than ground-level air. The relatively high humidity of winter air condenses in cold temperatures, forming a fog. Particles of air pollution, mostly from vehicle emissions, provide cores around which moisture can condense. Sulfur and nitrogen dioxides form sulfuric and nitric acid, irritating eyes and making breathing difficult.
Ozone is harmful at ground level, but the Earth is protected from harmful effects of solar radiation by a global layer of ozone in the upper atmosphere. Loss of this ozone layer allows ultraviolet light to penetrate to the Earth’s surface, causing harmful ozone to form there. Intense UV light can also trigger skin cancers and eye damage in animals and humans, disrupt photosynthesis, and damage aquatic life up to 20 meters beneath water surfaces.
Ozone naturally decomposes under sunlight, but certain air pollutants accelerate ozone decomposition. Hydroxide, chlorine, bromine, and nitrogen oxides are the chief catalysts of ozone decomposition. These compounds are releases into the atmosphere mainly by human activity. Chloro-Fluor-Carbons (CFCs) are especially dangerous because they are not used up during ozone decomposition, so they remain to accelerate ozone decomposition many times. CFCs have been banned from use in manmade products throughout most of the world.
The greenhouse effect, in which air pollution traps heat from sunlight to warm the Earth, leads to long term climate change. Nitrogen oxides, volatile organic compounds (VOCs), carbon monoxide, and carbohydrates are the chief air pollutants responsible for the greenhouse effect and climate change. All of these air pollutants are increased by human activities.
The bottom line is that air pollution has a huge effect on Earth.