Search results
Results from the WOW.Com Content Network
Smog, or smoke fog, is a type of intense air pollution. The word "smog" was coined in the early 20th century, and is a portmanteau of the words smoke and fog [ 1 ] to refer to smoky fog due to its opacity, and odor. [ 2 ] The word was then intended to refer to what was sometimes known as pea soup fog, a familiar and serious problem in London ...
e. Air pollution is the contamination of air due to the presence of substances called pollutants in the atmosphere that are harmful to the health of humans and other living beings, or cause damage to the climate or to materials. [ 1 ] It is also the contamination of the indoor or outdoor environment either by chemical, physical, or biological ...
An air quality index (AQI) is an indicator developed by government agencies [ 1 ] to communicate to the public how polluted the air currently is or how polluted it is forecast to become. [ 2 ][ 3 ] As air pollution levels rise, so does the AQI, along with the associated public health risk. Children, the elderly and individuals with respiratory ...
Looking down from the Hollywood Hills, with Griffith Observatory on the hill in the foreground, air pollution is visible in downtown Los Angeles on a late afternoon.. Air pollution is the introduction of chemicals, particulate matter, or biological materials into the atmosphere, causing harm or discomfort to humans or other living organisms, or damaging ecosystems.
Air pollution measurement is the process of collecting and measuring the components of air pollution, notably gases and particulates. The earliest devices used to measure pollution include rain gauges (in studies of acid rain), Ringelmann charts for measuring smoke, and simple soot and dust collectors known as deposit gauges. [ 1 ]
Contents. National Ambient Air Quality Standards. The U.S. National Ambient Air Quality Standards (NAAQS, pronounced / ˈnæks / naks) are limits on atmospheric concentration of six pollutants that cause smog, acid rain, and other health hazards. [ 1 ] Established by the United States Environmental Protection Agency (EPA) under authority of the ...
The Great Smog of 1952 in London. Early in December 1952, a cold fog descended upon London. Because of the cold, Londoners began to burn more coal than usual. The resulting air pollution was trapped by the inversion layer formed by the dense mass of cold air. Concentrations of pollutants, coal smoke in particular, built up dramatically.
Ground-level ozone. Seasonal average vertical columns of tropospheric ozone in Dobson units over the period 1979 to 2000. In June to August, photochemical ozone production causes very high concentrations over the East Coast of the US and China. Ground-level ozone (O3), also known as surface-level ozone and tropospheric ozone, is a trace gas in ...