industrial and economic development is accompanied, as a rule, increasing environmental pollution.Most major cities are characterized by a significant concentration of industrial facilities on a relatively small territory, that poses a risk to human health.
One of the environmental factors that have the most pronounced impact on human health is the quality of the air.A particular danger is now present emissions of air pollutants.This is due to the fact that the toxicants enter the human body mainly through the respiratory tract.
Air emissions: sources
distinguish natural and anthropogenic sources of pollutants in the air.The main impurities, which include emissions from natural sources, are dust cosmic, volcanic and vegetable origin, gases and smoke resulting from forest and steppe fires, debris and weathering of rocks and soils and so forth.
levels of air pollutionnatural sources are the background character.They are small enough to change over time.The main sources of air basin pollution at the present stage are man-made - namely industry (various sectors), agriculture and road transport.
plant emissions into the atmosphere
The largest "suppliers" of various pollutants into the air are the metallurgical and energy industries, chemical industry, construction industry, mechanical engineering.
In the process of combustion of different types of energy complexes in the atmosphere of a large amount of sulfur dioxide, oxides of nitrogen and carbon, soot.Also, emissions (in smaller quantities), there are a number of other substances, in particular hydrocarbons.
The main sources of dust and gas emissions in steel production - melting furnaces, casting installation, pickling department, sinter machine drobilnorazmolnoe equipment, loading and unloading of materials and so forth. The largest proportion of the total number of substances released into the atmosphere, take carbon monoxide, dust anhydridesulfur dioxide, nitrogen oxide.In a somewhat lesser amounts ejected manganese, arsenic, lead, phosphorus, mercury vapor, and so on. Also, in the process of steelmaking emissions containing gas mixture.They contain phenol, benzene, formaldehyde, ammonia and some other harmful substances.
harmful emissions from the chemical industry enterprises, despite the small volumes, are of particular concern for the environment and human, as characterized by high toxicity, concentration and considerable diversity.Entering the air mixture depending on the type of product may be composed of sulfur oxides, volatile organic compounds, fluorine compounds, nitrous gases, solids, chlorinated compounds, hydrogen sulfide and so forth.
In the production of building materials and cement emissions contain substantialvarying amounts of dust.The main technological processes leading to their formation are grinding, handling a mix materials, semi-finished products and products in the flow of hot gases and so on. Around the factories producing various building materials, can form the contamination zone radius up to 2000 m. They are characterized by high concentrations of airborne dust containingparticles of plaster, cement, quartz, as well as other pollutants.
emissions vehicles
In large cities a huge amount of pollutants in the atmosphere comes from motor vehicles.According to various estimates, they account for 80 to 95%.The exhaust gases consist of a large number of toxic compounds such as nitrogen oxides and carbon, aldehydes, hydrocarbons, and so forth. (About 200 compounds).
greatest emissions are observed in the areas where the traffic lights and intersections where cars move at low speeds and at idle.Calculating emissions indicated that the main components of exhaust in this case are carbon monoxide and hydrocarbons.
It should be noted that, unlike the stationary sources of emissions, work vehicles contributes to air pollution in the city streets at the height of human growth.As a result of the harmful effects of pollutants are subject to pedestrians, residents of homes located near roads, as well as growing on adjacent land vegetation.
Agriculture
emissions of harmful substances into the atmosphere in the rural areas are mainly the result of the activities of livestock farms and poultry farms.From the rooms, which contain livestock and poultry, the air coming hydrogen sulfide, ammonia and some other gases travel considerable distances.Also dangerous toxicants released into the air as a result of crop farms when spraying pesticides and fertilizers on the fields, treated seeds in warehouses and so forth.
Other sources
addition to the above sources, emissions of pollutants produced by oil and gas refineries.It also occurs as a result of mineral extraction and processing, with the release of gases and dust of the underground mines, burning rock in the dumps at the incineration plants and so on. D.
Impact on human
According to various sourcesthere is a direct link between air pollution and several diseases.For example, the duration of the flow of respiratory diseases in children who live in relatively polluted areas, 2-2.5 times longer than those that live in other areas.
In addition, the cities with adverse environmental conditions, children marked functional abnormalities in the immune system and blood formation, breach of compensatory-adaptive mechanisms to environmental conditions.Many studies also found a link between air pollution and mortality of people.
main components of emissions entering the air from various sources, are particulate matter, oxides of nitrogen, carbon and sulfur.It was revealed that the area of ​​exceedance for NO2 and CO cover up to 90% of the urban area.These emissions macro components can cause serious illness.The accumulation of these contaminants resulting in damage to the mucous membranes of the upper respiratory tract, the development of lung disease.In addition, elevated concentrations of SO2 can cause degenerative changes in the kidneys, liver and heart, and NO2 - toxicosis, congenital malformations, heart failure, nervous disorders and other. Some studies have found a relationship between the incidence of lung cancer and the concentrations of SO2 and NO2 in the air.
Conclusions
pollution of the environment and, in particular, the atmosphere has adverse health effects are not only present but also future generations.Therefore, we can safely say that the development of measures aimed at to reduce emissions of harmful substances into the atmosphere - one of the most pressing issues today humanity.
