Air pollution is the introduction into the atmosphere of chemicals, particulates, or biological materials that cause discomfort, disease, or death to humans, damage other living organisms such as food crops, or damage the natural environment or built environment. The atmosphere is a complex dynamic natural gaseous system that is essential to support life on planet Earth. Stratospheric ozone depletion due to air pollution has long been recognized as a threat to human health as well as to the Earth’s ecosystems. A substance in the air that can be harmful to humans ND the environment is known as an air pollutant.
Pollutants can be in the form of solid particles, liquid droplets, or gases. In addition, they may be natural or man-made. Pollutants can be classified as primary or secondary. Usually, primary pollutants are directly emitted from a process, such as ash from a volcanic eruption, the carbon monoxide gas from a motor vehicle exhaust or sulfur dioxide released from factories. Secondary pollutants are not emitted directly. Rather, they form in the air when primary pollutants react or interact. An important example of a secondary pollutant surround bevel ozone ? one of the many secondary pollutants that make up photochemical smog.
Some pollutants may be both primary and secondary: that is, they are both emitted directly and formed from other primary pollutants. Examples are Sulfur Oxide, Nitrogen Oxide, Carbon Monoxide, Carbon Dioxide, Cuff’s, Ammonia, etc. Secondary pollutants include Particulates from smoke, smog, Approximately nitrate Air pollution occurs when the air contains gases, dust, fumes or dour in harmful amounts. That is, amounts which could be harmful to the health or comfort of humans and animals or which could cause damage to plants and materials.
The substances that cause air pollution are called pollutants. Pollutants that are pumped into our atmosphere and directly pollute the air are called primary pollutants. Primary pollutant examples include carbon monoxide from car exhausts and sulfur dioxide from the combustion of coal. Further pollution can arise if primary pollutants in the atmosphere undergo chemical reactions. The resulting compounds are called secondary pollutants. Photochemical smog is an example of this. Air pollutants mainly occur as a result of gaseous discharges from industry and motor vehicles.
There are also natural sources such as wind-blown dust and smoke from fires. Some forms of air pollution create global problems, such as upper atmosphere ozone depletion and global warming. These problems are very complex, and require international cooperative efforts to find solutions. Global warming is the rise in the average temperature of Earth’s atmosphere and oceans since the late 1 9th century and its projected continuation. Since the early 20th century, Earth’s mean surface temperature has increased by about 0. 8 co (1. 4 OF), with about two-thirds of the increase occurring since 980.
Warming of decimated system is unequivocal, and scientists are more than 90% certain that it is primarily caused by increasing concentrations of greenhouse gases produced by human activities such as the burning of fossil fuels and deforestation. These findings are recognized by the national science academies of all major industrialized nations. Warming and related changes will vary from region to region around the globe. The effects of an increase in global temperature include a rise in sea levels and a change in the amount and pattern of precipitation, as well a rabble expansion of subtropical deserts.
Warming is expected to be strongest in the Arctic and would be associated with the continuing retreat of glaciers, permafrost and sea ice. Other likely effects of the warming include a more frequent occurrence of extreme-weather events including heat waves, droughts and heavy rainfall, ocean acidification and species extinctions due to shifting temperature regimes. Effects significant to humans include the threat to food security from decreasing crop yields and the loss of habitat from inundation.