4.1 Atmospheric Transport of Air Pollution

It is mentionable that, no considerable research on the atmospheric transport of air pollution is carried out in Iran.

Besides, we use from air pollutant transfer modeling of other countries in our studies and researches.

Meanwhile, there isn’t any book or article about this subject.

4.2 National Air Quality Criteria and Standards

A) The present national standards for various sectors are as follows:

1. The regulation of industry settlement and service
2. Clean air standards
3. The permissible limit of emissions from the exhaust of petrol vehicles in traffic.
4. The standard of emissions from the exhausts of imported petrol vehicles and those of manufactured in the country.
5. The standard of emissions from the different industrial factories and workshops containing different forty-nine processes and seventy-two permissible limits. Parameters of air pollutant.

1. To great the coordination for establishment of industries and industrial workshops on the basis of pollution intensity and abatement
2. To cause coordination and prevention from visual and sensational pollutants.
3. The reduction of pollution effect of caused by neighboring industries.
4. The reduction of pollution effect caused by industries in population centers.
5. Using unit management in national level.
6. The reduction of pollution caused by the emitted gases from the industries exhaust and vehicles by using suitable instruments.

The suitable establishment of industries and service centers is necessary to coordinate development with environment and the determination of the standards of industries establishment is unavoidable to reduce environmental impacts.

The present collection is based on the note 2 of article 13 of the law the way of preventing from air pollution approved by the respected

Islamic parliament in 22.4.1995 and with regard to the standards of industries establishment and service centers approved by environmental high council in 29.8.1993
 
 

Industries Classification and Determination.

Industries are classified with regard to production process:

1-Food industries.

2-Wearing industries.

3-Leather industries.

4-Cellulose industries.

5-Metal industries.

6-Nonmetal mineral industries.

7-Chemical industries.

8-Medicinal industries.

9-Electronic and electrical industries.

10-Agricultural industries.

The industries are based on the pollution intensity and mitigation and other environmental problems with the following particulars:

A Group

The industries of this group are permissible to be established in commercial or industrial areas within the approved urban restricted area.

Approved Urban Restricted Area

The approved urban restricted area consists of the latest restricted area of the comprehensive or conductive plan (in case of the lack of this two) service restricted area.

B Group

This group is permissible to be established with in the environmental limit of the cities with at least 2oo meter of residential, treatment and educational centers and one hundred distance of military and police centers and limits of the rivers and subterranean canal.

Environmental Limits

Environmental limits contain the tape, 10 kilometers wide after the approved urban restricted area for the cities with more than one million people and 5 kilometers for the cities between two hundred thousand to 1 million people and 3 kilometers for the cities between 75 hundred thousand to 200 hundred thousand and 2 kilometers for the cities less than 75 thousand people.

Residential Centers

Residential centers are referred to a series of residential units whose household has been defined as the minimum unit among country divisions.

The smallest unit of the country division destination is village which is traditionally called as village and hamlet and at least 20 households or one hundred whether centralized or dispersed are lived in there.

C Group

The industries of this group are permissible to be established in industrial area within environmental limits of every city or outside it and with the observation of at least 500 meters distance from the residential, educational and treatment centers, and with the observation of the legal limits. The agricultural industries of Group G item 10 of the classification of this criterion are not permissible to be established in industrial area. But they can be established outside the environmental limits according to above mentioned conditions.

Industrial Area

Industrial area is the limit, which is considered to establish industry by the related organization. These regions are determined and approved in comprehensive and conductive plans.

D&E Group

The industries of this group are permissible to be established outside the environmental limits of each city on condition that the necessary distances of important centers.

F Group

The suggested location for the establishment of industries of this group with regard to production process, area topography, climate conditions, environmental tolerable capacity, the direction of prevailing winds, urban development and other environmental parameters are surveyed by the experts of Department of the Environment and will be declared.

Note 1.

The replacement of industrial topics in various groups with regard to resulted pollution and the way of neutralization will be carried out.

Note 2.

The extraction and exploitation of mines are due to the observation of standards and criteria of pollution control. If the location of the mine is in the place where exploitation of it causes severe pollution and destruction of the environment, such exploitation will not be permissible. The above control criteria and standards will be compiled and declared by Department of the Environment with the cooperation of the Ministry of Mines and Metals.

Note 3.

The establishment of industries in disposed agricultural lands conceding with the laws and regulations is based on obtaining the agreement of Ministry of Agriculture.

1. The minimum distance of industries group D & E from important centers

• The industries, whose establishment at the seaside is unavoidable like shipbuilding, will be surveyed.
• In northern seashore states of the country in the regions where the main road beside the sea has the distance less than the above distance inserted in the table. The distance of the road from the sea as the distance of the sea to the industrial unit should be considered.
• Marshes are called to the regions like wet lands and pools, watery lands, natural or artificial marshes which are permanent or temporary with running and static water and fresh or salt taste, brackish containing marine areas with the depth less than 6 meters.
• Protected zone is based on the agreement of Department of Environment.
• National park is referred to a the limits of natural resource (such as forest, pasture, and natural woods and forests, plains and water and mountainous places, which show some distinguished aspects of Iran natural manifestations and for the sake of permanent situation of life and its natural condition and also causing suitable environment for duplication and raise of wild animals and the growth of vegetables in complete natural conditions is under preservation.
• Natural and national monuments are sample and rare phenomena of plants and animals, pictures or matchless sceneries and the particular qualities of the earth or old trees, which are under preserved considering suitable limits.
• Wild life shelter is referred to a restricted area of natural sources such as forest, pasture, plain, water and mountainous area, which has a natural habitats and special climatic condition for wild animals and has been conserved for the conservation and revival of these habitats.
• Protected zone is generally referred to a restricted area of natural sources of the country as forest, pasture, plain, water and mountainous areas which has importance and from the point of the necessity of conservation duplication of wild life generation or conservation

• General criteria of industries establishment

1. The last statistics of Iran statistics center are indicator of distinction of cities’ population.
2. Within the framework of the industrial cities criteria, establishment of all kinds of producing and industrial unit except for group F industries inside the towns on condition that the town has the zone classification of establishment, green space and central system of sewage purification is satisfactory.
3. These criteria can not contradict the sanctioned laws like the plan of industry and agriculture balance in Gilan and Mazandaran and prohibition within restricted area of 120 kilometers to Tehran and 50 kilometers to Isfahan and so on.
4. In exceptional cases that the possibility of execution of the establishment criteria in the state is impossible, the case is surveyed in the state committee containing the agents of general offices of Industries, Mines and Metals and Department of the Environment, Housing and Urban Development, Plan organization, Construction Crusade, Agriculture and the Development consideration of producing process, zone topography, climatic conditions, environment tolerable capacity, the direction of prevailing winds and urban extension about the industry location of establishment are basely determined. The secretariat of the above committee is located in the general department of environment of the state.
5. Owing to the importance of clean air in cities and residential regions of the country, the establishment of industries producing air pollution in the direction of prevailing wind to these regions should be prohibited.

• Should not occur more than once a year.
• Above standards have been given from WHO standards.

*-Reference weight is the vehicle weight ready to move without load, passenger and driver with the tank full of fuel and necessary accessories in addition to 100 kilograms.

- The approved of permissible limit of emissions from the exhausts of in operation petrol vehicles.

- Emission Standards From Industrial Workshops & Factories
 

Unit	Pollutant Industries	Gases Standard				Particles Standard			Darkness %		Remarks Number
		Kind of gas	Degree 1	Degree 2	Measurement unit	Degree 1	Degree 2	Measurement unit	Degree 1	Degree  2
Refinery	Catalyst regeneration system Crude oil reserve tanks  Products more than 1000 barrels	CO _	0.1 _	_ _	V% _	150 _	350 _	Mg/m3 _	30 _	30 _	2 3
Indirect heating Transmit instruments	Power stations-Refineries	SO2 CO NOx	800 150 350	800 150 350	PPM // //	150	350	Mg/m3	20	20	4 25
Steel mill plant	Coke producing plant Scanning operations-Crashing operations Clod making Blast furnace Oxygen main furnace Boron making furnace Electrical bow furnace	H2S _     CO CO _ CO	250 _     100 500 _ 500	500 _     250 500 _ 500	Mg/m3 _     Mg/m3 // // //	100 100     500 50 100 100	250 250     500 150 300 150	Mg/m3 //     // // // //	20 _     _ _ _ _	_ _     _ _ _ _	1 1     1 1 1 1
Removal of waste material	Removal of waste materials From the surface of steel parts by oxygen flame	_	_	_	_	50	150	Mg/m3	_	_	2
Copper primary melt plant	Copper dryers Liquidation furnaces-Copper converters	_ SO2	_ 800	_ 800	_ ppm	50 _	150 _	Mg/m3 _	20 20	_ _	5 5
Zinc primary melt plant	To red-hot the zinc  Clod making machine	SO2	800 _	800 _	PPM	_ 50	_ 150	_ Mg/m3	20 20	_ _	2
Lead primary melt plant	Blast furnace-Clod making machine Clod making machine  Liquidation electrical furnace or converter	SO2	_ 800	800	PPM	50 _	150 _	_	20 20	_ _	2 2
Electrical bow furnaces for producing alloys of iron in which electrodes stand in one base	Silicium metal  Ferro silicon alloy calcium silicon alloy or silico manganese zirconium. Silico manganes iron & silver alloy, Ferro chromium alloy Standard Ferro manganes, Ferro manganes silicon carbid-	CO     CO CO	20     20 20	_     _ _	V%     Maximum 500 PPM //	0.25     0.23 0.23	1     0.5 0.5	6     6 6	20     20 20	20     20 20	2     2 2
Aluminum primary regeneration plant	Electrolyt cells  Settlement location  Anode producing plant	F2	10	25	Mg/m3	75	150	Mg/m3	20	20	2
Brass or bronze bar Producing plant	Electrical furnaces  Concave blast furnaces	_	_	_	_	50	100	Mg/m3	20	_	7
Lead secondary melter and purifier	Blast furnaces Pot furnaces	_	_	_	_	50	100	Mg/m3	20	_	2
Castings	Concave furnaces-  Electrical induction furnaces Electrical bow furnace	_	_	_	_	50	850	Mg/m3	20	_	2
Stand preparing Operations and moulding of casting factory	Sand preparing-Mould preparing Breaking of mould	_	_	_	_	150	150	Mg/m3	_	_	-
Sulfur preparing  Plant	_	SO2 H2S	800 20	100 30	PPM //	_ _	_ _	_ _	_ _	_ _	8
Sulfuric acid producing plant in touching method or oleoume producing plant	Burning of sulfur-burning of sulfidric acid – Burning of alkylized acid – Burning of organic sulfur  Burning of mercaptane Burning of acid sludge	SO2         H2SO4	1000         40	1200         75	Mg/m3         Mg/m3	40         _	75         _	Mg/m3         _	10         10	20         20
Paper-mill  Process of sulfite in preparing of cellulose	Preparing of paper  Flammable liquids fuel	SO2 _	4.5 _	15 _	Kg/Ton _	150	250	Mg/m3	_	_	2
Paper-mill  Process of sulfate in preparing cellulose	Recycled furnace  (All of the regenerative sulfuric components such as sulfuric acid- Methyl mercaptane  Di methyl sulfuro- Di methyl  Di sulfuro- and so on according to sulfuric acid) Unexpansive gases from other units of paper-mill	_ _                 _	_ _                 _	_ _                 _	_ _                 _	150 5                 _	250 10                 _	Mg/m3 Mg/m3                 _	_                 - _	_                 - _	10
Acid phosphoric producing plant in wet method	Reactors-purifiers-dilute acid phosphoric reserve tank dilute acid phosphoric condenser- Refining tanks	F2	10	25	11	_	_	_	_	_	12
Super phosphoric acid producing plant	Evaporators- product condenser tanks-concentrated equipment	F2	5	10	11	_	_	_	_	_	12
Phosphate  Diamunium producing plant	Reactors – granulaters- desiccants- condensers screeners- millers	F2	30	50	11	_	_	_	20	20	12
Super phosphate producing plant in accumulation method	Mixers- carriers in which reaction is done. Other carriers- super phosphate reservers in which reaction is done.	F2	100	150	11	_	_	_	20	20	12
Super phosphate producing plant in granular method	Reactors- granulaters- desiccants- condensers-screeners millers	F2	100	150	11	_	_	_	20	20	12
Granular super phosphate reserve tanks	Elevators- heaps of product transmitters- screens mills	F2	0.5	0.75	13	_	_	_	_	_	12
Ammonia producing plant	Ammonia plant	NH3	50	100	PPM	_	_	_	_	_
Chloridric acid producing plant	Chloridric acid plant	HCL	100	300	Mg/m3	_	_	_	_	_	2
P.V.C producing plant	Producing of P.V.C	HCL	100	300	Mg/m3	_	_	_	_	_	2
Chloride Ferric producing plant	Producing of Chloride ferric	HCL	100	300	Mg/m3	_	_	_	_	_	2
Chloride Zinc producing plant	Producing of Chloride Zinc	HCL	100	300	Mg/m3	_	_	_	_	_	2
Chloride Nicle producing plant	Producing of chloride Nicle	HCL	100	300	Mg/m3	_	_	_	_	_	2
a -Chloro prophine  producing plant	Preparing of a -chloro prophine	HCL	100	300	Mg/m3	_	_	_	_	_	2
Translation & filler instruments of chloridric acid & the like chemical plant	Filler instruments of chloridric acid	HCL	100	300	Mg/m3	_	_	_	_	_	2
Cyanidric acid producing plant	Preparing of cyanidric acid	HCN	8	10	PPM	_	_	_	Not visible	20	-
Nitric acid producing plant	Nitric acid preparing unit Preparing of concentrated acid from dilute acid extraction operations vaporization operations	NOx	350	500	PPM	_	_	_	//	_
Sulfur carbon producing plant	Preparing of sulfur carbon sulfuric acid – oxi sulfur carbon	S2C	100	110	PPM	_	_	_	_	_	14
Smut producing plant	Wet gas filter-  Washing tower of  Plant –furnaces Furnaces	_ _ _	_ _ _	_ _ _	_ _ _	60 50 50	_ _ _	Mg/m3 // //	_ _ _	_ _ _	2 2 2 2
Glass factory & other factories whose fluorine is evacuated to the air	Preparing of glass	FH	30	40	Mg/m3	_	_	_	_	_	2
Refining plant sewage	Refining of sewage	_	_	_	_	0.60	0.65	15	_	_	-
Sodium carbonate & bicarbonate producing plant	_	NH3	5	5	Kg	_	_	16	_	_	17
Coal preparing plant	Heating desiccants splinters- Screeners coal reserve tanks- coal transmission points coal loading stages	_ _	_ _	_ _	_ _	75 40	150 100	Mg/m3 //	20 20	30 30	2 2
Cement preparing plant	Cook furnace Mill	_ _	_ _	_ _	_ _	100 150	150 200	Mg/m3 //	20 _	30 _	18
Asphalt preparing plant	Desiccants furnaces, elevators screens Asphalt reserve tanks Funnels- mixers of asphalt Reserve tanks of asphalt Mineral materials Instruments and equipment of dust transmission into controller equipment	_	_	_	_	100	250	Mg/m3	20	25	2
Ceramic producing plant	Cook furnace	F2	10	25	_	200	300	Mg/m3	_	_	2
Asbestos plant	Preparing of asbestos	_	_	_	_	20	27	Mg/m3	_	_	2
Plaster producing plant	Plaster preparing different stages	_	_	_	_	250	600	Mg/m3	_	_	-
Lime producing plant	Furnace – mill Equipment that slake the lime Transmission of lime Loading of lime	_	_	_	_	100	250	Mg/m3	20	30	2
Brick plant and other plants of clay derivatives	Cook furnace – (emission fluorine from cook furnace) Particles emission from preparing of brick	F2 SO2 _	10 800 _	25 _ _	Mg/m3 PPM _	100 _ 150	250 _ 250	Mg/m3 _ 250	20 _ _	30 _ _	2 2 2
Incinerator of animals corpse	From incinerator chimney	_	_	_	_	_	_	_	_	_	21
General incinerator	From incinerator/chimney	_	_	_	_	150	250	Mg/m3	20	30
Industrial units (work shops and factories)	Any production process	SO2 H2S CO F2	800 10 350 10	800 25 500 25	PPM Mg/m3 // //	100 100 100 100	250 250 250 250	Mg/m3 // // //	20 20 20 20	_ _ _ _	24 24 24 24

Definition (Remarks number):

1. Average amount for one hour in ordinary and dry conditions

2. In ordinary and dry conditions

3. Real steam pressure between 75-58ommHg become equipped

to floating ceilings

4. According to heavy fuel consumption

5.Darkness for two minutes per hour (2min/h)

If production plant of sulfuric acid used for controlling of sulfide

Dioxide ,if it will be upper than permissible limit for two minutes ,there is

No objection.

6. Kg/megawatt hour

7. Burner’s trade standard is 100 Kg/hour and high furnace standard

is 250 Kg/hour

8. Sulphidric acid turns to sulphid dioxide and it is discharged to air.

9. Kilogram in lieu to one ton of dry paper

10. Before discharging to air, we omit heating oxidation or equal method

11. Gram in lieu to one ton of consumption original materials

12. According to phosphoric anhydride

13. Gram in lieu to reserved granulate super phosphate

14. In ordinary and dry conditions ( It is permissible, when the diameter

of particles is lower than 30 micron )

15. Gram in lieu to Kilogram of soda

16. Kilogram in lieu to one ton of soda

17. Factories work with salvi method

18. Temperature:200ºC - Barometer: 760mmHg

19. Emission gases according to mg/m³

20. The capacity is over than 25 ton in 24 hour

21. In lieu to any kilogram of corpse produce1200 g/s
22. Gram in lieu to one million calory
23. The capacity is over than 413 x 10 calory per hour arise from heavy oil fuels
24. Other industrial units that haven’t compiled standards for them

Numerous factors must be examined about air pollution impacts on human health.

Many efforts have done to research the air pollution impacts in usual concentrations of urban.

These studies show that occur dramatic and unexpected disasters and register immediate deaths arising from air pollution.

Therefore, since the confirmation of air pollution impacts on human health, is difficult affair, we try to do extreme efforts for anticipating of determined amounts of pollutants impacts in the specified time.

Respiratory organs examination and defensive mechanisms of body against pollutants show that we have several methods to leave the inhaling pollutants like as gases or particles.

The great particles don’t entry to air-sacs the particles, that their sizes are smaller than 0.5 micron, precipitate in the lower parts of respiratory organs.

Amount and place of particles precipitation follow of size, physical activity and respiratory aggravation. The most important diseases of air pollution are respiratory diseases like as bronchitis, lung cancer, emphysema, activity reduction of respiratory flagellum, bacterium infections and other cancers (resulting from carcinogen components like as Benzo pyrene in air)

It is mentionable that some of the pollutants such as No2 create the bearing power in laboratory animals.

Pollutants impacts on human health.

Sulfur dioxide ( SO2)

The studies are performed on three important disasters in Belgic Mioz vallay, London and Denovar have shown high mortality resulted from respiratory diseases, while 25% ppm of this pollutant and 1000 mg particles in air may enhance the respiratory diseases and by increase this value to 35% resulting in more deaths and 5% ppm of So2 and 2000 mg of particles increase the mortality up to 20%. In this manner, scientists of Arizona University showed that the existing of So2 in blood, lead to reduce DNA amount and change the number of chromosomes.

So2 gas destroys lymphocytes and reduces the body resistance.

At the time of humidity existence and oxidation factors, So2 is converted to sulfuric acid that have the unpleasant impacts. Two mg/m3 of So2 results in stuffiness.

Ozone (O3)

Ozone has three oxygen that arises from photochemical impact of sun light on pollutants caused by burning.

This gas with 0.05 concentration result in provoking the nose and throat. One ppm amount of this gas and 30 minutes contacting with it, cause the headache. Contacting with upper concentrations of this gas causes to pain and high inflammation in respiratory organs.

Lead ( Pb)

Lead accumulation on nervous systems causes to change the external nerves protective cells and their fat. Lead causes anemia, poisoning, indisposition in synthesis of hemoglobin, increase of red blood vessels destruction, impact on hemoglobin productive enzymes and reduction of red blood vessels life.

Lead affects on kidneys discharge and reduces the renewed absorption of amino-acids, glucose, uric acid, nitric acid and phosphate.

Intense poisoning with lead causes the lack of fertilization and results in abortion of fetus and premature labor.

The researches show that the poisoned children with lead would have bad treats like quarreling, attacking and restlessness. Laboratory studies on animals have shown that lead exposure to 11 mg/m3 for 6 hours during 15 days causes diseases like sleepless ness, nervous annoyance, careless, mind reduction and brain losses.

Carbon monoxide (CO)

This gas affects immediately on blood hemoglobin that causes tiredness, poor vision, faintness, headache, and sleeplessness.

More intensive effects of this pollutant includes changes in blood vessels walls, heart and brain cells losses, and in high concentrations cause unconsciousness and death.

Nitrogen oxides (Nox)

Nitrogen Dioxide can convert to carcinogen nitrous-amine in lungs and make disease in blood. This gas incites lungs and creates the disease like emphysema. Contact with this gas (0.06-0.1 ppm) for 6 months results in increasing of respiratory diseases.

Hydrocarbons (HC)

Importance of this group of pollutants is due to their secondary compounds and formaldehyde, keton, PAN and other oxidants production. Permissible limit of these pollutants is 160 mg/m3 or 0.24 ppm. Existence of nitrogen oxide and ultraviolet ray increase the amount and poisoning of secondary compounds.

Suspended particles

Any kind of solid or liquid substance that it’s size is between 0.0002 to 500 micron, is called particle. When lungs absorb the particles, they entry to blood by lymphocyte. Contact with silica particles creates fibrosis and silicosis diseases in lungs.

Damage to plants

The impacts of air pollution on plants must be recognized like as industrial pollution especially metal melting industries.

Air pollution causes three problems for plants:

Acute effects of pollutants (in high concentration and short time) that cause necrosis and cells death, chronic effects of them that cause chlorosis and leaves falling and finally, these pollutants reduce production and growth of plants.

When the impacts of air pollutants on plants are surveyed, many alternatives such as plant diseases, feeding, insects and pests, climate, pollutants kind and contact time must be regarded. Moreover, impacts of So2 also must be regarded.

Ozone impacts on plants

Contact with normally amount of this gas causes to create the spots on the upper level of leaves, premature senility and growth reduction of pine and alfalfa.

High concentration of this gas causes necrosis and whitening the low level of leaves and acute damages on plants like as spinach, lettuce and flowers.

O3 and NO2

It is very difficult to evaluate the economical damages from pollution on plants. This matter is related to many reasons such as demonstration of growth and consumption reduction.

In spite of all of them, the exact studies seldom can calculate direct damages on plants, forests and vegetations and indirect damages result from pollution and soil erosion.

Air pollution impacts on corrosion, buildings and art works

Air pollution causes to corrode the metals, construction materials, textile, leather, plastic and art works. Sulfur dioxide and nitrogen dioxide (second gas has less share) cause metals corrosion.

Conversion of SO2 gas to Sulfuric acid, existence of pollutants like as smut, relative humidity and temperature cause to corrode the metals such as iron, steel, zinc and other elements like as rail roads, aerial systems, bridges, gable roof, oil transmission lines and etc.

Many plants are sensitive to O3 with concentration of 0.6 ppm This sensitivity causes to create scattered burning spots in the low level of leaves. These spots are called mosaic disease. The highest concentration of O3 affects on forests, especially evergreen trees. .

O3 gas can enter in photochemical smog circle and PAN production. This compound (in concentration of 0.03 ppm) affects

on plants, especially sensitive plants like as spinach, lettuce and some of the flowers. The signals of this pollution contain necrosis, to be bronzed in low level of leaves, plant growth reduction and crop reduction.

Fluorine

Fluorine is one of the most important of phytotoxins. This gas emits to air from some industries like as aluminium and, glass making, petrochemical industry, oil refinery and construction materials production (brickklin and mosaic plant). Some of the plants like as Glayol are sensitive to this gas. This material spreads in the form of Flouridric acid and causes burning of leaves (from the top of leaf to the end of it). Reduction of interchange level of gases in leaves causes the crop reduction and damage. One of the most intensive impacts of fluorine is it’s accumulative impact.

Constructive stones like as lime and dolomite are damaged by Sulfuric acid.

Sulfur spots with particles remain in the stones. Air pollutants like as So2, O3 and nitrogen oxides reduce color and stability of cloth. Air pollutants also cause to damage art works and treasures like as painting tableaus (impact of H2S on color), constructions and statues (impacts of nitrates, sulfates and chloride) and also paper and leather.

In this manner, financial losses determination and their estimate are difficult work.

Impacts of air pollution on domestic animals

These researches show that in the animal husbandries near to the air pollutant centers like as industries, consumption centers of phossile fuels, milk production is reduced resulting from SO2, CO gases in high concentration. Absorption and accumulation of fluorine in plants, especially forage resulting in entrance of this matter into animal food chain. Fluorine also causes fluorosis disease. This disease is leading to paralysis.

Visibility

Visibility distance is the longest distance of one direction that we can see the things without using of instruments and with unequipped eyes. Changing in visibility due to particles and gases that cause to change the light way and reduction the visibility. The existence particles in air are the most important factor for vision poor. Light absorptive is followed from light wavelength, particles size, their form and bright properties of suspended particles. In other words, light transmission is followed the size and form of particles, no their mass. Sun light wavelength is from 0.4 to 0.8 micron and when the particles are in those ranges (0.1-1 micron) the visibility will reduce.

These particles have influenced on visibility and respiratory systems. In any case, the visibility has reverse relation with particles concentration and spreading coefficient.

If the particles concentration is more than 100 mg/m3 and the particles size is between 1- 0.1 micron, the visibility will reduce. In spite of cases that we explained, the gases like Co2 and steam are effective on visibility because of light absorption or radiation ability. It is mentionable, the existence of particles and absorption of sunlight energy make cold the earth, where the existence of two above mentioned gases, cause to increase earth temperature.

The sulfur compounds (0.2-0.9 micron) form proportionately 5 to 20 percent of suspended particles.

These pollutants have the most influence on visibility that cause to increase suspended particles in the air and reduce the visibility.

Acidified of rivers and soil

Acid gases like as Sox and Nox by reason of oxidation, return to the soil by rain. These waters come in the surface waters and cause to change PH of water.

In recent two- decays, the studies and researches have been doing about PH changes in those rivers, lakes and soils that they are exposed by acid rains.

Acid rains with lower PH are effective on aquatic animals and plants in rivers and lakes and cause to become extinct sensitive species.

The acid rains change the PH of soil and finally, cause to change the ecosystems. (through the changing of vegetation)

The researches have distinguished that the pure water in the balance with the free ambient air has 5.7 PH, when there is Co2 in air.

The major anions in acid rains are So4^2-, No3^-, Cl^-, that So4^2- has high concentration in among them. Sulfuric acid is the most important component of acid rains. Nitric acid has less role.

Analysis of drafts motion shows that the acid rains are related to draft motion above sulfur sources before raining and nitrogen oxides spread.

4.4 Future Trends in Emitting Sources and Emissions

According to the studies happened in 1375 more than 5 million ton pollutants have emitted into Iran’s atmosphere. The polluted air lead s to various disease especially respiratory ones and continuous contact with polluted air endangers human being’s health seriously. Such problems are serious in Iran and large cities of this country like Tehran, mashad and Isfahan are seriously exposed to pollution.

Almost all the researches about the emission of the pollutants in the urban atmosphere relate Tehran. Considering the topographical situation the establishment of thousands of pollutant sources, the consumption of millions liters of fossil fuel, daily traffic of one millions motor vehicle and four hundred motor cycle, the lack of ventilation and refiner parameters in Tehran, can define this city as one of the polluted cities of the word.

The surveys show that each day 2500 tons carbon monoxide enters the air of Tehran so that this amount is caused by motor vehicles fuel. (94%) Nitrogen oxides, organic gases and hydro carbons 25% sulfur oxides caused by fossil fuels combustion especially power stations 18% and suspended particles 17% are among the pollutants of the city. Moreover considerable amounts of acid, aldehyde, amonia, ozone and other poisonous substances enters the air of the city, too.

The level of pollutants emission in other cities has not been studied yet, but Isfahan and Mashad are also exposed to the serious danger of air pollution and about Tehran, it is predicted that with regard to the current procedure of production and emission of pollutants, appearing inversion and chemical smog particularly in winter causes critical situation so that one of the Tehran air survey centers has predicted that if such situation takes place, (on the average once every 3 months), at least one week public vacation is necessary to reduce these effects.

Transport crew

In Iran the crew of used vehicles are classified in four categories as petrol cars, vans, motor cycles and diesel cars (truck, bus, minibus). In 1991 about 4 million cars run in the country that with regard to the 4% growth rate, this number has amounted to 5.1 million cars in 1997. It is estimated that 60% of petrol cars of the country have been used more than 15 years. But exact information is only about Tehran. Among 15000 buses in the city, 4000 ones belong to Vahed Company with the average use time 12.6 years and 4000 minibuses that 70% of them have been used more than 11 years. In Tehran there are 74600 Taxis, and other carrying passengers vehicles and 79000 private cars are in use. All of these vehicles produce 94% carbon monoxide. Considering the 4% growth rate for public vehicles, if we presume this amount constant, it is observed that in near future pollution caused by public vehicles of the country witch 65% the total pollutants of Iran will be a serious problem.

Activities done to reduce the pollution caused by traffic.

1. The introduction of hydrogenic fuel for combustible motors .
2. The substitution of petrol without lead and compressed natural gas or liquid gas in the cars that with regard to increasing consumption of petrol without lead, at present the considerable reduction of lead is observed in cities air.
3. The adaptation plan of exhaust pollutants (24-6) with the 15.04 ECE and 94.12 EEC standards in large car factories.
4. The equipment plan of motors in to injective mechanism.
5. The adaptation plan of exhaust pollutant of diesel cars with 49 ECC, EURC 2,3

• The air pollution caused by stationary sources and industrial, domestic and commercial sources

The appendix tables show the consumption fuel in each section, and the amount of pollutants emission.

The activities done to decrease the pollutants emission

Iran is among a few countries in the constitutional law of which, environmental protection has been considered. In addition, the law of environmental modification and protection approved in 1974 and its amendment dated 1992 and the organization of environmental high council and its authorities has been decided.

In stationary sources, the following methods are carried:

1. Considering the urban and industrial gas network and use of gas instead of oil and sulfuric fuels.
2. Use of the pure technology in industrial processes.
3. The compilation of national management programs of industrial wastes.
4. Care for environmental considerations in location industries and earth applied designing.
5. Recovery of methane gas from the sanitary land fills.
6. The increase of combustion systems output and avoidance of fuel consumption with high sulfur.
7. The reduction thermal loss of the buildings and the improvement of construction methods.
8. Establishment and proper strategy of the control systems of industrial air pollution.
9. Gradual reduction and prohibition of the consumption of asbestos.
10. Increase of urban green spaces.
11. Improvement of energy consumption pattern through educational actions.
12. Gradual reduction of fossil fuel subsidy.
13. Reinforcement of research activities.

Section	Diesel oil	Gas oil	Kerosene
Industries	37.7	17.9	2
Agriculture	0.3	37.2	3.1
The army	1.6	4.1	1.4
Electricity	41.7	10.5	0.3
Merchants	14.8	3.7	3.7
Heat	-	19.1	85.8
Others	4	7.5	3.7
Total	100	100	100

Fuel	Pollutant	Sulfur dioxide  SO2	Particles	Nitrogen oxides NOx	Hydro carbons HC	Carbon monoxide CO
Kind	Amount of Consumption (1000 m3)	Amount  (Ton)	Amount  (Ton)	Amount  (Ton)	Amount  (Ton)	Amount  (Ton)
Diesel oil	14828	815540	40777	88968	7858	7414
Gas oil	11082	188394	19947	88656	2773	5541
Kerosene	10484	24113	14677	15726	2096	4193
Total	36394	1028047	75401	193348	12724	17148