SMOG POLLUTANTS IN CALIFORNIA

Smog Pollutants in California



Smog Pollutants in California

Historically, the term smog referred to a mixture of smoke and fog, hence the name smog. The industrial revolution has been the central cause for the increase in pollutants in the atmosphere over the last three centuries. Before 1950, the majority of this pollution was created from the burning of coal for energy generation, space heating, cooking, and transportation. Under the right conditions, the smoke and sulfur dioxide produced from the burning of coal can combine with fog to create industrial smog.

In high concentrations, industrial smog can be extremely toxic to humans and other living organisms(Turner, 1994). Vehicle engines, which are extremely numerous in all parts of the world, do not completely burn the petroleum they use as fuel. This produces nitrogen dioxide which is released through the vehicle exhaust along with a high concentration of hydrocarbons. The absorption of solar radiation by the nitrogen dioxide results in the formation of ozone (O3). Ozone reacts with many different hydrocarbons to produce a brownish-yellow gaseous cloud which may contain numerous chemical compounds, the combination of which, we call photochemical smog.

Today, the use of other fossil fuels, nuclear power, and hydroelectricity instead of coal has greatly reduced the occurrence of industrial smog. However, the burning of fossil fuels like gasoline can create another atmospheric pollution problem known as photochemical smog. 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. Development of photochemical smog is typically associated with specific climatic conditions and centers of high population density.

Cities like California frequently suffer episodes of photochemical smog. California, for all of its great weather and sunshine, has to put up with something called an inversion layer(McMurry, Grosjean, 1985). A common occurrence in the Summer, a time when Los Angeles experiences its worst air quality, an inversion layer is nothing more than an area of the atmosphere where the normal cooling of air temperature with increasing elevation slows down or even reverses. Normally, air temperature cools down rapidly as you climb higher and higher up into the atmosphere. With an inversion layer, the air temperature will cool off much slower than normal or the temperature will actually increase as you gain altitude. What this does is cause a layer of warmer air to cover the colder air below it; the inversion layer acts like a lid on whatever is underneath it - in this case air! What happens is that in a place like Los Angeles, with its 3million plus residents and millions and millions of cars on the road, all that noxious gas and pollution gets released into the air but upon contact with the inversion layer, the pollution gets trapped; it has nowhere to go! So, instead of dissipating into the upper atmosphere, this "smog" gets stuck in the ...