What is air pollution

Show Less air pollution control, the techniques employed to reduce or eliminate the emission into the Air is considered to be polluted when it contains certain substances in concentrations high enough and for durations long enough to cause harm or undesirable effects. These include adverse effects on human health, property, and atmospheric visibility. The atmosphere is susceptible to pollution from natural sources as well as from human activities. Some natural phenomena, such as Most air contaminants originate from The primary focus of air pollution regulation in industrialized countries has been on protecting ambient, or outdoor, air quality. This involves the control of a small number of specific “criteria” pollutants known to contribute to urban The best way to protect air quality is to reduce the emission of pollutants by changing to cleaner fuels and processes. Pollutants not eliminated in this way must be collected or trapped by Control of Airborne particles can be removed from a polluted airstream by a variety of physical processes. Common types of equipment for collecting fine particulates include cyclones, scrubbers, electrostatic precipitators, and baghouse filters. Once collected, particulates adhere to each other, forming agglomerates that can readily be removed from the equipment and disposed of, usually in a Get a Britannica Premium subscription and gain access to exclusive content. Because each air pollution control project is unique, it is usually not possi...

Air pollution refers to the release of pollutants into the air—pollutants which are detrimental to human health and the planet as a whole. According to the World Health Organization (WHO), each year air pollution is responsible for nearly seven million deaths around the globe. Nine out of ten human beings currently breathe air that exceeds the WHO’s guideline limits for pollutants, with those living in low- and middle-income countries suffering the most. In the United States, the The effects of air pollution on the human body vary depending on the type of pollutant and the length and level of exposure—as well as other factors, including a person’s individual health risks and the cumulative impacts of multiple pollutants or stressors. Smog and soot These are the two most prevalent types of air pollution. Smog (sometimes referred to as ground-level ozone) occurs when emissions from combusting fossil fuels react with sunlight. Soot (also known as Smog can irritate the eyes and throat and also damage the lungs, especially those of children, senior citizens, and people who work or exercise outdoors. It’s even worse for people who have asthma or allergies: these extra pollutants can intensify their symptoms and trigger asthma attacks. The tiniest airborne particles in soot, whether gaseous or solid, are especially dangerous because they can penetrate the lungs and bloodstream and worsen bronchitis, lead to heart attacks, and even hasten death. In 2020 a report from Harvard’s T. ...

Pollution is the introduction of harmful materials into the environment. These harmful materials are called pollutants. Pollutants can be natural, such as volcanic ash. They can also be created by human activity, such as trash or runoff produced by factories. Pollutants damage the quality of air, water, and land. Many things that are useful to people produce pollution. Cars spew pollutants from their exhaust pipes. Burning coal to create electricity pollutes the air. Industries and homes generate garbage and sewage that can pollute the land and water. Pesticides—chemical poisons used to kill weeds and insects— seep into waterways and harm wildlife. All living things—from one-celled microbes to blue whales—depend on Earth’s supply of air and water. When these resources are polluted, all forms of life are threatened. Pollution is a global problem. Although urban areas are usually more polluted than the countryside, pollution can spread to remote places where no people live. For example, pesticides and other chemicals have been found in the Antarctic ice sheet. In the middle of the northern Pacific Ocean, a huge collection of microscopic plastic particles forms what is known as the Great Pacific Garbage Patch. Air and water currents carry pollution. Ocean currents and migrating fish carry marine pollutants far and wide. Winds can pick up radioactive material accidentally released from a nuclear reactor and scatter it around the world. Smoke from a factory in one country drift...

When air quality is good, the air is clear and contains only small amounts of solid particle and chemical pollutants. Poor air quality, which contains high levels of pollutants, is often hazy and dangerous to health and the environment. Air quality is described according to the Air quality along the Front Range of the Rocky Mountains in Colorado is sometimes good (top) and sometimes poor (bottom). Often called “the brown cloud,” poor air quality in this location is frequently caused by a thermal inversion, where cold air descending from the higher elevation mountains traps vehicle exhaust and pollutants near the surface, resulting in hazy conditions that are high in pollutants. iStock Dave Parsons (top image), Steven Krull (bottom image) Why Does Air Quality Change? Because air is always moving, air quality can change from day to day, or even from one hour to the next. For a specific location, the air quality is a direct result of both how air moves through the area and how people are influencing the air. Humans Affect Air Quality Geographic features such as mountain ranges, coastlines, and land modified by people can cause air pollutants to concentrate in, or disperse from, an area. However, the types and amounts of pollutants entering the air have a much larger impact on air quality. Natural sources, such as volcanic activity and dust storms, add some pollutants to the air, but most pollutants come from human activity. Vehicle exhaust, smoke from coal-burning power plant...