The central province of Yazd is going through the most polluted Iranian month caused by the spread of dust particles since at least March 2016, a provincial weather official said.
"Yazd has so far suffered ten days of unhealthy air quality in the current month of Khordad [beginning May 22], compared to one recorded polluted day in the same month last year and seven days in the year before," Mostafa Mirzadeh said in an interview with IRNA.
"Air Quality Index hit a range of 150-200, an alarming level for all groups," he warned on Tuesday, predicting the situation will continue on a declining trend toward the end of the day.
The AQI measures the concentration of particulate matter and other pollutants in the air.
Its readings are based on a scale of up to 500, which describes conditions as Good (0-50), Moderate (51-100), Unhealthy for Sensitive Groups (101-150), Unhealthy (151-200), Very Unhealthy (201-300) and Hazardous (301-500).
Pollution in the provincial capital of Yazd has reached more critical levels than in other cities of the province, Mirzadeh said.
"Dust storms, aided by a recent westerly-northerly weather system, led to the high levels of pollution in the province over the past couple of days," the expert said.
He named poor vegetation cover and parched farms as the main culprits behind high concentrations of dust particles in Yazd's air, noting that other contributors vary from season to season.
