Tehran Ozone Pollution Wanes

Air quality monitoring stations in the Tehran metropolis showed that its residents inhaled more clean air in September compared to a month ago, as ozone pollution waned. 
According to Tehran Air Quality Control Company, mostly “moderate” status dominated the month, keeping Air Quality Index between 51 and 100.
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).
Pollutants pushed the API to the “unhealthy” threshold for the sensitive group in the remaining six days. Children, pregnant women, cardiovascular and respiratory patients and the elderly form the group.