To solve the problem of air pollution, we should identify the main sources of pollution at first. The researches show that main sources of pollution are urban transport, urban industries, and domestic and commercial sectors. Currently, about 75 to 80 percent of air emissions in urban areas, especially large cities in Iran and in the world, are related to the urban transport sector . This includes ground, air and rail transport. A significant number of them is related to ground transport and in particularly to private cars and motorcycles. Actually, the density of cars and motorcycles that consume energy inefficiently is one of the important factors of urban air pollution. It should not to be ignored the role of industry in pollution, however.

Public transport can be considered to three important factors in pollution in this section: The density of vehicles, inefficient fuel use of vehicles and fuel quality. For example, if we compared the percentage of trips within the city with the subway, bus, taxi, bike and car in fifth program of Tehran, we will see that the percentages in the fifth program. Comparison of these figures indicates proximity to the objectives of the program and, in some cases passing of the objectives of the fifth program Tehran. Now the question is what is the reason of pollution?

In addition to environmental issues (including the reduction of atmospheric precipitation and the wind blowing in favor of) one of the factors is the number of cars and motorcycles in Tehran. According to statistics in 94, about 3.5 million motorcycles in the traffic in Tehran.

This number is a considerable origin of pollution in Tehran. According to one of the statistical centers, 24% of air pollution in Tehran is related to motorcycles, more polluted than private cars, due to their low-tech. On the other hand a significant number of cars, 3/3 million, are commuting in Tehran. The capacity of this metropolis is only 1.5 million.

Air pollution has different origins. Each of these pollutants has its own effects. . Among the types of air pollution in cities, generally the main problem is related to fine particles matter in the air called aerosols leading to irritation of the respiratory tract and bronchitis, asthma and lung disease and eventually to death. On the other hand, the particles absorb light, the sun’s rays from reaching the earth and cause serious problems for public health. Sun light reduces to one-third and two-thirds in industrial and urban areas in summer and in winter.

Some of these pollutants are converted to acid (acid rain) in combination with water in the air. They influence on buildings and cultural heritages. Some increase global temperatures and have environmental effects caused by melting polar ice and glaciers, and as a result, sea level rise, flooding and the destruction of fertile land. In Iran, according to reports, studies and responsible organizations, air pollution has devastating effects on human societies, nature, infrastructure and it has indirect economic effects.

Tehran is the 30th polluted and crowded city in the world; the expectation of solving air pollution problem by urban management is not fair, he added.