The cities of Ahvaz and Isfahan have earned the unflattering title of Irans most polluted cities over the past decade.
Speaking to Mehr News Agency, Shina Ansari, the head of Environmental Monitoring Office at the Department of Environment, said analyses of data compiled over the past 10 years show that the air in Ahvaz and Isfahan has the highest PM10 (particulate matter up to 10 micrometers in size) concentrations in the country.
PM10 concentrations were on average 80% and 30-50% above acceptable levels in Ahvaz and Isfahan respectively.
Particulate matter comprises smoke and dirt as well as dust from factories, farming and roads. It is unsurprising then that these two cities are Irans most polluted metropolises.
Ahvaz in the oil-rich Khuzestan Province has been grappling with dust storms for a decade. The storms, which have increased in frequency and severity over the years, have domestic and foreign sources.
Outdated oil extraction procedures have turned the once thriving Hoor al-Azim Wetland into a vast, dry patch of land.
Turkeys extensive dam and hydropower construction has reportedly reduced water flows into Iraq and Syria by approximately 80% and 40% respectively, which has transformed fertile lands into barren landscapes.
In 2011, a survey by the World Health Organization found Ahvaz to be the worlds most polluted city.
With 948 industrial units, Isfahan Province is Irans most heavily industrialized province. The concentration of industrial units in Isfahan has taken a toll on the regions and especially the provincial capitals air quality.
Last week, Saeed Motesadi, a deputy at DOE, said the spread of industrial units in Iran is unprecedented and stressed that the department is committed to remedying the problem by facilitating the relocation of industrial units to designated zones.
Not all is grim, however.
The data also show that carbon monoxide concentrations are on the decline, Ansari said.
She attributed the decline in CO levels to the governments move to introduce Euro 4 emission standards.
The official said the number of air-monitoring stations across Iran have increased by 33.3% year-on-year since 2011, which help the department extract more accurate data.
In 2011, there were only 133 monitoring stations, but in 2014 we had 186, she said.
Ansari said special equipments to monitor PM2.5 levels were purchased and installed last year and added that 84% of stations can monitor PM2.5 concentrations.