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Tehran Skies Get Duller in April as Pollution Worsens

Citizens of Iran's capital Tehran inhaled more poisonous air in April than in the same month of the previous year, data released by Tehran Air Quality Control Company show.

Charts published on TAQCC’s website, Airnow.tehran.ir, show that clean blue skies were not seen for even a single day, indicating that the air quality index did not fell into the "good" category in that month.

The index categorizes conditions dictated by a measure of polluting matters into good (0-50), moderate (51-100), unhealthy for sensitive groups (101-150), unhealthy (151-200), very unhealthy (201-300) and hazardous (301-500).

Moderate air pollution status dominated the month, keeping the index between 51 and 100 in 28 days. TAQCC data show that during the period, sensitive groups in the capital were warned to limit their outdoor activities in the remaining two days, as the index entered the threshold of 101-150 that categorizes the condition as “unhealthy for sensitive groups”.

Children, the elderly, pregnant women and those with respiratory and cardiovascular conditions fall in the above group.

Because of the high density of toxic pollutants, AQI reached 112 on April 9, the highest level during the period under study. 

Pollutants measured to determine air quality include carbon monoxide, nitrogen dioxide, sulfur dioxide, ground-level ozone and particulate matters (PM2.5 and PM10). AQI figures are calculated based on the concentration of pollutants.

Analyses illustrate that the pollutant responsible for all polluted days recorded in the period under review was PM2.5 (atmospheric particulate matters that have a diameter lower than 2.5 micrometers).

 

 

Quality Declines Year-on-Year 

Things are getting worse year-on-year since AQI was comparatively lower on average during April last year.

A large number of people stayed home in self-quarantine, as the novel coronavirus rampaged across Iran. Data show Tehran’s residents were exposed to cleaner air in April 2020 compared to the previous month.

TAQCC charts show that clear blue skies were seen on eight days of the month, meaning that the air quality index was under 50.

During the month, “moderate” status was the most prevailing air condition, as the index hovered between 51 and 100 on the remaining 22 days.

In fact, air quality condition was even better during the same period of a year before. In April 2019, AQI had 13 “good” and 17 “moderate” days.

 

 

Main Culprits

While there are various debates on the causes of poor air quality in the metropolis, the head of TAQCC earlier blamed 100,000 dilapidated passenger cars in Tehran.

Hossein Shahidzadeh added that over 3.43 million passenger cars ply the capital’s streets every day, 100,000 of which are over 18 years old and have outlived their usefulness.

He noted that these old cars emit 579,000 tons of toxins into the air annually, which means 1,586 tons per day.

Giving more specific information, Shahidzadeh noted that of all the pollutants annually spewed into Tehran’s air, these dilapidated cars are responsible for 82% of sulfur oxide, 23% of PM2.5 and PM10, 46% of carbon monoxide and 45% of nitrogen monoxide.

He also said PM2.5 is the most harmful pollutant due to its ability to penetrate deep into the lungs and bloodstreams unfiltered, causing heart attacks, respiratory diseases and premature deaths.

Shahidzadeh called the officials in charge to more seriously monitor the technical efficiency of cars plying Tehran’s streets. 

 

 

Substandard Vehicles

The low quality of even new vehicles produced by domestic manufacturers has also added to the problem. 

According to Hossein Moqaddam, CEO of Tehran Vehicle Technical Inspection Bureau, over one-third of vehicles in Tehran failed emission standards and technical inspection tests.

“In the last Iranian year [ended March 20, 2021], 1.66 million vehicles visited the capital's technical inspection centers, of which 1.19 million were under four years old and underwent their first technical check,” he said.

"Of the 597,600 new vehicles rejected, 17% did not receive the certificate due to high emission, 11% for wheel alignment, 4% for shock absorber failure, 13% for brake system problems and 16% for appearance issues.” 

Moqaddam noted that during the period, 1.13 technical certificates have been issued, of which 850,000 were regular and 283,000 were premium type.

The premium certificate has higher standards than that of the normal technical inspection certificates. While in normal tests, vehicle emissions are monitored in a low-speed mode but for receiving the premium certificate, the carbon monoxide emission of cars is assessed at 2,500 rpm.

Tehran Municipality’s Transportation and Traffic Organization has estimated that air pollution in the capital costs $2.6 billion annually.

Nonstandard and polluting vehicles spew poison into the air, threaten people’s lives and damage the environment.

According to the Department of Environment, the share of vehicles in air pollution is very high and according to the Health Ministry, some 12,000-14,000 people die because of pollution-related problems. 

It’s time officials address the air pollution crisis more seriously and with greater determination.