Carbureted motorcycles main source of ozone pollutants in Tehran

July 12, 2019 - 18:20

TEHRAN – Following consistent ozone pollution in Tehran’s hot season, motorcycles running on carbureted engines are considered as the main contributors to air pollution, Khabaronline reported on Wednesday.

Ozone in the lower atmosphere is formed by the reaction of sunlight on air containing hydrocarbons and nitrogen oxides (NOX) that react to form ozone directly at the source of the pollution namely, cars, industry, gas vapors, chemical solvents, fuel combustion.

Although the concentration of other pollutants in the capital has decreased since the beginning of spring (March 21) compared to the same period last year, however, during the third month of spring, ozone reached up to a level which was unprecedented in the past 17 years.

According to the Air Quality Control Company, Tehran’s air was unhealthy for sensitive groups for 17 days during this month, and polluted air for all the citizens haunted the capital for 1 day.

The statistics show a concentration of ozone increases in the capital during summer heats.
In fact, polluted summer phenomenon has haunted the metropolis of Tehran since 3 years ago which has been compounded this year.

Last year, Tehraners experienced 15 days of polluted air quality contaminated by ozone, thus, this was much less compared to the previous years.

Diesel cars and carbureted motorcycles are the major sources generating NOx; therefore, solutions are required to reduce the number of these vehicles in order to mitigate ozone.

Currently, some 2.5 million motorcycles are plying Tehran streets, of which some 2.4 million are carbureted equipped, and some 1.5 million are extremely old emitting particles.

On the other words, carbureted motorcycles account for 96.7 percent of all motorcycles running in the capital, while 61.8 percent of which are clunker playing a vital role in ozone pollution raise.

According to the clean air law, no license plate for carbureted-engine motorcycle should be issued unless a clunker carbureted motorcycle is scrapped, Hossein Shahidzadeh, caretaker for Tehran Air Quality Control Company said.

The clean air law constituting 35 articles has been drawn up by the Department of Environment as an integrated approach to curb air pollution, which was passed by the parliament on July 16, 2017. The law singles out inefficient vehicles, substandard fuels, industrial activities, and dust storms as the major sources of air pollution in the country and tasks different organizations with specific actions in line with the objective.

“Carbureted motorcycles scrapping process has awaited implementation in recent years due to executive and legal problems as well as increased unemployment,” Shahidzadeh noted.

He went on to say that fuel injection must replace carburetors on motorcycles due to being 90 percent less pollutant, and if their filter works well, these will not contribute to ground level ozone.

In addition to discarding carbureted motorcycles, the government should support the owners of clunker motorcycles to exchange their vehicles with electronic ones, he concluded.

Air pollution seriously hurts

According to WHO, 9 out of 10 people now breathe polluted air, which kills 7 million people every year. The health effects of air pollution are serious – one third of deaths from stroke, lung cancer and heart disease are due to air pollution. This is having an equivalent effect to that of smoking tobacco, and much higher than, say, the effects of eating too much salt.

According to WHO, 9 out of 10 people now breathe polluted air, which kills 7 million people every year. The health effects of air pollution are serious – one third of deaths from stroke, lung cancer and heart disease are due to air pollution.

Air pollution is closely linked to climate change - the main driver of climate change is fossil fuel combustion which is also a major contributor to air pollution - and efforts to mitigate one can improve the other.

There are two main types of air pollution –  ambient air pollution (outdoor pollution) and household (or indoor) air pollution refers to pollution generated by household combustion of fuels (caused by burning fuel such as coal, wood or kerosene) using open fires or basic stoves in poorly ventilated spaces. Household air pollution kills 4 million people a year.

Air pollution has a disastrous effect on children. Worldwide, up to 14 percent of children aged 5 – 18 years have asthma relating to factors including air pollution. Every year, 543,000 children younger than 5 years die from respiratory disease linked to air pollution. Air pollution is also linked to childhood cancers. Pregnant women are exposed to air pollution; it can affect fetal brain growth. 

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