Air pollution caused by chemical reactions among various substances and pollutants in the atmosphere. See smog.
Smog produced by action of solar radiation, especially of ultraviolet radiation, on exhausts from vehicles and industry. Photochemical smog irritates the eyes, nose and throat and damages plants. As smog increases, it can trigger more serious health problems e.g. asthma, bronchitis, increased susceptibility to respiratory infections and decreased lung function.
Ozone air pollution. Ozone is a secondary pollutant because it requires sunlight ("photo") and a chemical reaction between primary pollutants, NOx and Volatile Organic Compounds (VOCs), such as unburned gasoline or evaporating paint thinner. Also referred to as smog ozone.
Brown haze that blankets a city when exhaust from cars and trucks reacts in the presence of sunlight.
Complex mixture of air pollutants produced in the lower atmosphere by the reaction of hydrocarbons and nitrogen oxides under the influence of sunlight. Especially harmful components include ozone, peroxyacyl nitrates (PANs), and various aldehydes. Compare industrial smog.
Smog caused by the formation of particles due to chemical reactions driven by sunlight
produced when hydrocarbons and oxides of nitrogen combine in the presence of sunlight to form ozone
describes the hazy conditions which occur when air pollutants are trapped at ground level. High levels of ozone may be produced as nitrogen oxides and hydrocarbons react in the presence of sunlight. Pollution concentrations may become very high and the air quality may be classed as 'poor' or 'very poor'. In summertime, they usually occur on warm, still, sunny days. In winter, smogs may occur on cold, calm days when air pollutants are trapped in urban areas by a layer of warmer air above.
fo-to-KEM-i-kal SMOG A form of air pollution caused by vehicle emissions. 892
collection of harmful materials in the air resulting from the action of sunlight on nitrogen oxides, hydrocarbons, and other chemicals in the air. Photochemical smog generally develops in cites with warm climates or during summer months.
a complex mixture of oxidant gases and hydrocarbons produced by the action of sunlight in polluted air.
Air pollution caused by chemical reactions of various pollutants emitted in the presence of sunlight.
Air pollution caused by chemical reactions of various pollutants emitted from different sources.
a mix of photochemical oxidant air pollutants produced by the reaction of sunlight with primary air pollutants
air pollution caused by chemical reactions among various substances and pollutants in the atmosphere in the presence of sunlight; ozone is a major constituent
air pollution produced by the action of light on oxygen, nitrogen oxides, and unburned fuel from auto exhaust to form ozone and other pollutants.
present in many large cities, is formed by chemical reactions involving nitrogen oxides and hydrocarbons (from human activities including automobile use) taking place in the presence of sunlight. The principle component of photochemical smog is tropospheric or ground-level ozone.
A brownish smog occurring in urban areas receiving large amounts of sunlight; caused by photochemical (light-induced) reactions among nitrogen oxides, hydrocarbons and other components of polluted air that produce photochemical oxidants.
Photochemical smog is a condition that develops when primary pollutants (oxides of nitrogen and volatile organic compounds created from fossil fuel combustion) interact under the influence of sunlight to produce a mixture of hundreds of different and hazardous chemicals known as secondary pollutants. Also see industrial smog.
layer of pollutants generated in the lower atmosphere by the action of sunlight on gaseous pollutants such as VOCs and NOx. Also known as summertime smog Polluter Pays principle: the principle that polluters bear the costs of dealing with the problems caused by the pollution they generate.
Air contaminated with ozone, nitrogen oxides, and hydrocarbons, with or without natural fog being present. In the presence of sunlight, hydrocarbons and NOx are involved in a complex series of chemical reactions that eventually creates ozone and other oxidants as secondary pollutants. However, ozone is also destroyed by NOx. Photochemical air pollution levels are generally proportional to concentrations of nitrogen oxides and hydrocarbons; they also increase with strong solar intensity and high ambient temperatures, which increase biogenic volatile organic emissions to the atmosphere from vegetation. The pollutant levels are inversely proportional to wind speed and inversion height. See also smog.
