Financial Tribune - Data show that during the month, “moderate” status was the most prevailing air condition, as the index hovered between 51 and 100 in May on 28 days 

The Iranian capital’s residents inhaled more polluted air in May compared with the same period of last year, data from Tehran Municipality show.

Charts published by Tehran Air Quality Control Company’s website, Airnow.tehran.ir, show that air quality was healthy on only one day in the month, as the air quality index was under 50.

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).

TAQCC data show that during the month, “moderate” status was the most prevailing air condition, as the index hovered between 51 and 100 in May’s remaining 28 days.