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.