Air pollutants are all materials that (regardless of their origin and condition) reach into the air to such an extent that they can damage humans and their environment or cause material damage.

Pollutants in the air may be natural and artificial (anthropogenic) sources. Anthropogenic pollutants come from three main areas: transport, energy production and industry. Incineration of fossil fuels is the most important source in these sectors. Natural air pollutants include volcanoes (sulfur oxides and powders), forest fires (carbon monoxide, carbon dioxide, nitrogen oxides and powders), wind storms (dust), live plants (hydrocarbons, pollen), decaying plants (methane , hydrogen sulphide), soil (viruses, dust) and sea (salt).

Types of sources of air pollution

 

Air pollutants may originate from point sources or diffuse sources. Point source where concentration and volume flow can be clearly defined. Surface (or diffuse) source is where indirect material measurements and calculations refer to the amount of substance entering the environment. Subdivisions of diffuse sources can be considered as linear air pollutants.

The stages of air pollution

The process of air pollution consists of emissions, transmissions and immission. Emission means the amount of material released into the air, a unit of kg / hour, the transmission spread, and the immission means the ambient air quality at a certain location.

Airborne contaminants may be gases, dusts, fogs or fumes. One group of powders is the depositing powder (1000-10 mm), the other the floating powder (10-0.1 mm).

Combining secondary (secondary) air pollutants from the primary (primary) air pollutants in the atmosphere with other materials (eg sulfur dioxide with oxygen and water vapor).

Most important air pollutants, sources and their effects

The type and amount of emission depends on several factors. These include: fuel for energy production, heating, modern industrial production, degree of separation of air pollutants, number of vehicles and technical condition, population and climate.

Air pollution is a symptom of the unsustainable transport and energy industry. The health-damaging effect depends on the exposure time and the concentration of the pollutant.

Some significant air pollutants are listed below:

  • Carbon monoxide, which comes mainly from the transport industry (transport) (in addition to mining, combustion), may result in reduced concentration and death. It forms a carboxyhemoglobin in the blood of the hemoglobin of blood. Chronic exposure leads to cardiovascular disease, myocardial infarction.
  • Oxides of sulfur that are fired from fossil fuels and industry (production of sulfuric acid, mining, ore preparation, cellulose production) are caused by airborne respiratory diseases. Chronic exposure leads to chronic bronchitis. In the air, sulfuric acid and sulfuric acid are formed with oxygen in the air, leading to acid deposition. (For discussion of acid sedimentation, see "The Soil.") Sulfur dioxide is the main component of the London type smoke (see "Smoke" later).
  • Nitrogen oxides are produced in nitrogen fertilizer production, nitric acid production, transport, and energy production. Especially the eye's mucous membrane is excited. Nitrogen dioxide combines in the air with oxygen and water nitric acid which, like sulfuric acid from sulfur dioxide, leads to acid deposition. Nitrogen dioxide is the main component of the Los Angeles type smog (see "Smoke" later).
  • Powders of various particle sizes (from industry, especially mining, cement industry, combustion of fuels, etc.) are the cause of respiratory and cancerous diseases. Particularly dangerous particles of 0.25 to 10 mm in diameter due to their adhesion to the lymph nodes. Depending on the quality of the inhaled powders, people are causing various diseases (such as silicosis, asbestosis, warts, cottonseed). Their harmful effects on plants are that the gas exchange openings are clogged, thus preventing the plant from being water absorbed.
  • Hydrocarbons (transport) including carcinogenic components (eg benzpyrene).
  • In agriculture, in addition to the natural contaminants, the fertilizers and the pesticides (pesticides) powder.
  • Flue gas generated from combustion processes is mainly caused by the services and households. It contains carbon monoxide, carbon dioxide, water vapor, carbon black, sulfur dioxide, nitrogen oxides, methane, hydrocarbons, etc.
  • Indoor air pollutants:
    • cigarette smoke with carbon monoxide, powders, sulfur dioxide, nitrogen dioxide (from cigarettes, pipes and cigars)
    • radon: naturally occurring radioactive material in the soil (causing lung cancer)
    • Formaldehyde (new furniture, saw blade) causes eye and respiratory irritation
    • asbestos (from insulation to the apartment): causes respiratory illnesses.

Air pollutants also cause significant economic damage in addition to their harmful effects on human and animal health. These include loss of production due to illness, increased consumption of medicines, and damage to monuments.

Impact of air pollution on various materials:

  • metals: corrosion (sulfur dioxide, hydrogen sulphide, powders)
  • marble and limestone: surface erosion, discoloration, storm (sulfur dioxide, powders)
  • paints: discoloration, becoming obsolete, corroding (sulfur dioxide, nitrogen oxides, hydrogen sulphide, powders, ozone)
  • rubber and skin: becomes fragile (primarily due to ozone and other photochemical oxidants).

Solution options:

The solution of air pollution is divided into two types of processes: passive and active methods.

The passive methods only be placed on a target to reduce pollution and mainly composed of gas cleaning processes, site of the spill. They can be based on physical, chemical or biological methods. Pollutants can be filtered by air filters, chemically cleansed, or can be emptied out of the gas. The big problem with these methods is that the pollutant itself - if it is not in the air - but it will remain and require further treatment. Air pollution control with filtering techniques generally has a great cost. The real solution is therefore prevention.

The essence of active processes is prevention of air pollution, that is, emission reduction. Its tools include using the right raw material, technological change, switching to a closed process in production, recycling, using renewable energy sources, saving and population control. For example, aluminum recycling reduces air pollution by 95% compared to the production of primary aluminum, paper recycling is approx. 75, and steel reduces air pollution by 85% (see Table 2, p. 57).

Linear sources can reduce emissions by installing catalysts for vehicles that convert air pollutants into less hazardous substances - at least for human health.

Practical implementation of emission reduction should be a multi-stage process. The first step is to create an accurate picture of the extent of soil contamination. This is given by an environmental monitoring. The second step is to establish realistic immission norms. This is followed by determining the emission standards necessary to comply with the immission norms, which always depends on local conditions (eg terrain, weather). There is a short deadline to be imposed on polluting plants and institutions above norms. Finally, it is necessary to check and, if necessary, act on the force of the law (if necessary with a temporary stop) to comply with the norms.