After a week, city air clears, PM 2.5 within limits

According to the data from the Central Pollution Control Board (CPCB), the concentration of PM 2.5 on Tuesday in Alandur was 63 µg/m3 and 49 µg/m3 at Velachery. With the pollution levels in the city reaching above 300 µg/m3, concerns of health impact and respiratory problems were raised among the public.

The pollution level started to decrease in Manali on Monday and touched 91 µg/m3. The value was 211 µg/m3 in Alandur till then.

When contacted, a senior official at the Tamil Nadu Pollution Control Board said, “The pollution started decreasing from Monday evening.”

Chennai’s air quality deteriorated since November 4. According to aqicn.org, the count of fine particles (particulate matter less than 2.5 microns) on last Wednesday morning was 180, which is unhealthy.

Thermal power plants not responsible for spike in pollution, claims Tangedco

The increased air pollution in Chennai in the last few days cannot be attributed to thermal power stations in Ennore region, as they were being well maintained and are in continuous service throughout the year, said Tangedco.

In a statement, Tangedco said that the North Chennai Thermal Power Station I, in service since 1994, is equipped with Electro Static Precipitators (ESP) that were originally designed to precipitate the Particulate Matter (PM) of value up to 150 mg/Nm3 (milligrams per cubic meter) based on the prevailing Environmental Act for that period.

After the norms were revised, administrative approval has been given to renovate the ESP of all three units to bring down the PM value within 100mg/Nm3, it said, adding that it would be completed before 2022. It added that the PM value generally varies from 74mg/Nm3 to 190mg/Nm3 – it ranged from 123 to 245 mg/Nm3 on November 6.

It also said that a green belt area of about 232 acres comprising of about 32,000 trees are being maintained in both thermal stations. “Further, it is also planned to plant more than 6500 trees before March 2020,” the statement noted.