Tehran Air Quality Improves Slightly in May

Charts published on TAQCC’s website, Airnow.tehran.ir show that in May, Tehran’s residents breathed less polluted air. 

Clean blue skies were seen for two days recently with the air quality index showing "good" condition. 

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), according to Financial Tribune.

The other 29 days of the month had a "moderate" status, with the index hovering between 51 and 100.

TAQCC data show that in May, sensitive groups in the capital were not warned to limit their outdoor activities, as the index did not enter 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.

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

Analyses illustrate that the pollutant responsible for the 29 moderate days recorded in the investigated period was PM2.5 (atmospheric particulate matters that have a diameter of less than 2.5 micrometers).

Things Getting Better

Figures indicate that people in Tehran are breathing more clean air these days, as the number of days with suffocating air pollution has declined over the past few years, at least during the period under review.

May 2018 did not have a satisfying resume, as sensitive residents were advised to limit their outdoor exertion for three days, with the index remaining “unhealthy” for the group. 

“Moderate” air condition was recorded for 24 days in the month, with AQI standing between 51 and 100. The bright blue skies appeared only for four days with the index remaining between 0 and 50, which indicates a "good" status.

The high concentration of PM2.5 was the key factor behind the high AQI.

A glance at the same period in 2017 shows that air quality conditions have become better year after year. 

In May 2017, the traffic congested metropolis saw no days with good air. “Moderate” air quality was the most prevalent condition, for the index stood between 51 and 100 for 27 days.

The rest of the month faced air pollution that forced sensitive groups indoors for four days, with AQI standing between 101 and 150. 

Once again, PM2.5 was responsible for the high AQI during the period.

Risks and Measures

Poor air quality has long troubled all urban residents in Iran causing over 12,000 pollution-related deaths in the fiscal 2016-17.

Seemingly, things are getting better at least in Tehran. This could either be thanks to Nature's help or healing measures introduced by municipal bodies.

One of the latest measures is the air pollution reduction scheme implemented in the metropolis in November 2018.

As per the scheme, dilapidated vehicles are banned from the roads and violators are fined. 

All four- and two-wheelers must undergo mandatory technical inspections and acquire conformity cards showing that the vehicles are roadworthy.