There are many natural causes of air-pollution, like wind storms and dust particles. Because we live in Britain, much of our air pollution is blown out to sea. This also means that one of the most common air pollutants in the UK is sea salt. Live plants produce pollen and hydrocarbons, dead plants emitte methane and hydrogen Sulphide but rarely reach harmful levels.
The most significant sources of air-pollution are volcanoes and forest fires. Forest fires emitte pollutants like Nitrogen oxides, Sulpher Dioxide and Sulpher Trioxide.
Pollutants caused by human activity often enter the atmosphere through the burning of fossil fuels in stationary sources (power plants and factories) or mobile sources. Urban areas usually have much higher air pollution levels than rural because of the large amount of cars and factories. Indoor pollutants are chemicals used in buildings or manufactured inside buildings. These chemicals produce many problems for human health.
Photochemical smog is a mixture of primary and secondary pollutants activated by sunlight to produce a chemical reaction. This mixture of over 100 chemicals is a highly reactive gas that harms many organisms. Photochemical smog can be found over cities in the form of a brownish cloud on sunny days. This gas damages crops and trees and at its peak it can irritate the eyes. Large cities and tropical Amazon forests can produce high levels of photochemical smog. In rain forests, trees and other vegetation release hydrocarbons that react with Nitrogen Oxide in the sun.
Industrial smog is created when fossil fuels like coal and oil are burned in power plants and factories. During winter in the 1950s, cities such as London were exposed to industrial smog. Today there is more control over these gases being emitted and in developed countries, coal and oil are usually burned in large boilers and Smoke stacks carry pollutants to less populated areas. In countries like China there is less control over pollutants and a large number of people burn coal in there homes. This fills their houses with toxic fumes, it is estimated that 2.8 million people die each year from indoor air pollution.
Indoor air pollution:
According to the EPA, more than 3000 cases of cancer in the United States could have been caused by indoor air pollutants. Smokers, Infants aged under five, pregnant ladies and the elderly are all at high risk. Many illnesses have been linked to indoor air-pollution: sore heads, dizziness, coughing, sneezing, sore eyes and other flu-like symptoms may have been linked to `sick building syndrome’.
The three most dangerous indoor air-pollutants are tobacco smoke, formaldehyde and radioactive radon gas. Exposure to asbestos fibers in the workplace is mainly a serious issue in developing countries.
Building materials, furniture, upholstery and nail polish all contain small amounts of formaldehyde. Approximately one in five thousand people who live in modern homes for over ten years will develop cancer from formaldehyde exposure.
Radon-222 is a natural radioactive gas that is found in most soil. It seeps up through the ground and can enter buildings through cracks and drains. When inhaled, radon-222 exposes lung tissue to radiation and can lead to lung cancer. Smokers are most at risk though, the national Academy of Science estimates that twelve percent of fatalities caused by lung cancer are due to radon-222 exposure.
“The English disease”
In the early nineteenth century only around half of the children born lived past the age of five. Thousands of infants died because they were brought up in industrial areas. They suffered from Rickettes which was commonly known over seas as `The English Disease’. Rickettes is caused by a deficiency of vitamin D in their bodies. The children were unable to absorb ultraviolet rays from the sun as they were constantly surrounded by thick industrial smoke. People became concerned as the effects of air pollution became clear to them.
In 1952, over a period of three weeks there were 4000 deaths in the London area. That was well above the number of expected deaths for the entire year. The lack of movement in the air and the low temperature was noticeable. A layer of cold air was trapped underneath a layer of warm air because of the thick smoke for four days. From the 5th of December till the 8th the smoke wouldn’t move. Instead of the smoke being carried away by the wind, it settled in a thick layer over London.
The level of smoke and Sulpher Dioxide increased rapidly on the 5th. It first became clear that something was really wrong at a cattle show. Some of the cattle had developed acute respiratory symptoms. There was an increase in breathing and their tongues were hanging out. 160 cows needed to see a vet, then twelve cattle needed to be slaughtered as they were found to have pneumonia. At the same time many civilians in London were suffering from sever chest infections. Some of these people died as a result of these illnesses. Although the increase in deaths was mainly in elderly people there was a sixty percent increase in deaths at the ages of fifteen to forty four and a one hundred and eighty percent increase at the ages of forty five and seventy four.
A post mortem of the bodies revealed that they had lost the lining layer of cells in the bronchi and were found to have an increase of phlegm. This was the worst case of which a prolonged exposure to smog has caused so many deaths in London but there were other similar cases. Two severe fogs on Glasgow in 1909 which caused an increase in deaths have been noted. This shows the dramatic and fatal effects that industrial smog can have on the mortality rate and the amount of non-fatal illnesses it can also cause. There are other contaminations found in the air in towns and cities besides industrial smog but they are more difficult to monitor.
Conclusion
A high level of air pollution damages human health as well as the entire atmosphere. Air pollution is a major environmental and public health hazard, especially for the developing world. The studies of air-pollution and the health risks are limited, there is not enough evidence to say how much of a threat outdoor and indoor pollution really is on the health of humans. The air quality of Britain has been improving throughout this century because of controls and law being enforced but is still not as good as it should be. There is still a lot of work to be done especially in the third world and co-ordinated international efforts are necessary to save the biosphere from further damage as the quality of the environment we live in is accountable for the quality of our lives.
References:
Air Pollution and climate change – Alan Wellburn
Air Pollution – W.M Thring
Living in the environment – G Tyler Miller
