Environmental protection - air pollution
When you burn fossil fuel, youre combining the carbon it contains with oxygen in the air to release heat. However, the process also creates byproducts that are potentially dangerous. In addition, the usual fuels used in transportation, such as gasoline or diesel, arent a single substance, but a chemical soup of ingredients such as butane, propane, xylene and benzene.DOWNLOAD REFERAT
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Carbon based petrochimical products are broken up in combustion to form, among many other products, carcon dioxide, carbon monoxide, volatile organic compounds, nitrogen oxides, sulphur oxides and very fine particulates. In addition, unburned hydrocarbons, some of which evaporate directly from the gas thanks of cars and trucks, escape before and after combustion and join other VOCs in the air
When sufficient concentration of sulphur and nitrogen oxides and hydrocarbons builds up in the atmosphere and is bombarded by sunlight, a complez series of chemicals, including nitrogen dioxide and ozone. Also, very fine acidic particles are formed, such as sulphates and nitrates. These fine particulates are so small they are drawn deep into our lungs, causing stress to our cardiopulmonary system.
To understand these byproducts, it is useful to consider how theyre used in more concentrated form by industry. Nitrogen dioxide is a poisonous brown gas used as a catalyst and oxydizing agent. Nitric acid is a transparent, fuming corrosive liquid that is a highly reactive oxidizing agent used in the production of fertilizers, explosives and rocket fuels. Ozone is an unstable oxidizing agent, poisonous in high concentrations, with a pugent, irritating odour. In weak concentrations, ozone is used as a bleach and to sterilize water.
In effect, breathing air containing these chemicals is like breathing diluted quantities of poison gas, acid and bleach.
What is its effects?
Human can be adversely affected both before and after the burning of fossil fuels. Before burning, fumes from evaporating petroleum fuels can be poisonous and carcirogenic in high concentrations. In addition a third group of toxical chemical by-products is subsequently formed from reactions of combustion products in the atmosphere.
Fine particulates are particles do small they remain suspended in air where they can be inhaled and deposited deep in the respiratory system. Primary fine particulates are released directly into the air drom sources such as tailpipes. Secondary dine particulates are formes from physical and chemical reactions involving gases such as Nox, Sox, and VOCs, emitted into the air.
Fine particulates are associated with respiratory syptoms, increased emergency room vicits for asthma, increased hospitalization, imapired lung function, increased absence from work and increased death from cardiopulmonary disease and lung cancer. Children, the elderly, smokers, asthmatics and others suffering from respiratory disorders are especially vulnerable to this type of air pollution.
Current research indicates that fine particulate matter is the air pollutant with the graetest immediate health impacts- and resulting costs.
As well as causing health damage, fine particulates can lead to major reductions in visibility. Although it is difficult to put a dollar figure on the loss of visibility, it is clear British Columbians value the beauty of the environment. Recent scientific research indicates that vehicle emissions and wood smoke are the greatest caused of reduced visibility in B.C. « mai multe referate din Engleza