Financial Tribune- A s Tehran's air quality began to hit unhealthy levels, the authorities were left with no other choice but to take the same emergency short-term measures such as traffic restrictions and schools closures.

The air quality index began to rise over the healthy threshold of 100 on Friday and reached 115 on Saturday.

To help alleviate the condition, cars were banned from entry into the city on Sunday based on their plate numbers and the sale of daily permits for the traffic zone was suspended.

Kindergartens and primary schools were also shut down and sensitive groups, including the elderly and those with respiratory and heart problems were alerted. Restrictions were enforced on construction work and factory operations as well as heavy vehicles, ISNA reported.

Nevertheless, pollution levels continued to grow hitting 161 (unhealthy for all groups) compelling the authorities to extend the measures for another day.

The poor air quality affected the whole province, so the same policies were carried out in other counties including Rey, Varamin, Shahriar, Shemiranat, Qods, Qarchak, Pakdasht and Malard.

Other metropolises, including Karaj, Arak, Isfahan and Mashhad, also experienced heavy pollution as a result of the stable weather conditions since Friday.

Iran Meteorological Organization has forecast improvements in air quality with rain clouds entering the country from the north and northwest. The system is expected to move on toward the central and southern regions on Tuesday and on to eastern areas on Wednesday.

Controversial Criterion

In Tehran, the Air Quality Index based on which short-term palliatives are employed and the public is alerted is the 12-hour average while most experts believe that the maximum figure should be used as the standard.

According to Shina Ansari, head of the Monitoring Office at the Department of Environment, the decision has been made only for Tehran due to its vast area.

"The maximum AQI is used in all Iranian metropolises except Tehran," she said, ISNA reported.

Mohammad Ali Ehteram, faculty member at Shahid Beheshti University, has criticized the approach maintaining that all large cities of the world use the maximum figure to better protect the public. Vahid Hosseini, director of Tehran Air Quality Control Company, said the DOE had adopted this policy in the past years and communicated it to the company.

He added that the TAQCC would immediately shift to measuring the maximum AQI upon DOE's order.

"We have notified the DOE and the Health Ministry multiple times. The Health Ministry agrees with going for the maximum but the DOE insists on using the average figure."

Yousef Rashidi, a professor at Shahid Beheshti University, believes that considering the maximum AQI is a better method provided that the figures are measured with standard techniques.

"It is essential that the air quality monitoring stations be located in places that can well represent the entire city. Data from a gauge next to a terminal or one far away from congested areas could not be generalized to the whole urban area," he said.

In addition, he suggested a careful zoning of Tehran based on air quality models and making specific decisions for each zone separately.