Environmental protection - air pollution
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.[...]DOWNLOAD REFERAT
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To understand these byproducts, it is useful to consider how they're 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. « mai multe referate din Engleza