New Delhi: The air quality in the national capital and regions around it improved from "severe" to "very poor" on Wednesday but the environment panel imposed curbs on some industries amid forecasts that pollution may worsen.
The Supreme Court-appointed Environment Pollution Control Authority (EPCA), which is monitoring the pollution levels, announced restrictions on construction activities, hot mix plants, coal and biomass-based industries, brick kilns and stone crushers in the NCR.
It said it can restrict movement of private vehicles and entry of trucks to Delhi, if needed.
"The coming days could see a sharp deterioration in air quality in Delhi-NCR," EPCA said. It added that the coal-based Badarpur power plant was already shut and diesel generator sets were banned in Delhi since October 15.
On Wednesday, despite a slight improvement due to winds, the air quality was still "severe" in many places. The air quality in Gurugram in Haryana was still in the "severe" category.
Pollution levels in Delhi-National Capital Region are likely to see a spike in coming days, as farmers in neighbouring Punjab and Haryana step up stubble burning.
EPCA has ordered closing down the entire industrial area of Mundka in north Delhi from November 1 to November 10 while the municipal corporation clears plastic, rubber and other wastes.
EPCA has also requested people in Delhi to avoid using private vehicles between November 1 and November 10.
At 4 p.m. on Wednesday, the Air Quality Index (AQI) of Delhi was 358 or "very poor", against 402 on Tuesday. The AQI of Gurugram was severe at 416.
Meanwhile, Ghaziabad in Uttar Pradesh saw an improvement in AQI to 362. At Noida and Greater Noida, AQI was 347 and 383 respectively.
According to the Central Pollution Control Board (CPCB), the "severe" levels affect healthy people and seriously impact those with existing diseases. The "very poor" levels cause respiratory illness on prolonged exposure.
"There is increased burning of paddy straw in Punjab and Haryana, the direction of the wind is now from the northwest. All this, combined with Delhi-NCR's own pollution sources, could lead to a spike in pollution in the coming 10 days," EPCA said.
On Wednesday, almost all places in the NCR saw a drop in the the major pollutants PM2.5 and PM10 -- particles in the air with diameters less than 2.5 mm and 10 mm respectively.
Across 35 areas in Delhi where pollution is actively monitored, the average concentration of PM2.5 and PM10 was 221 and 408 microgrammes per cubic meters on Wednesday at 7 p.m., against 263 and 472 units on Tuesday.
The same PM2.5 and PM10 concentration across 48 monitoring stations in the NCR was 209 and 386 on Wednesday, against 257 units and 457 units on Tuesday.
The safe limit for PM2.5 is 60 units as per national standards and 25 units according to international standards. For PM10, up to 100 units is safe by national standards and 50 units by international standards.
Both PM2.5 and 10 get into the lungs and cause cardiovascular and respiratory diseases, but PM2.5 is more dangerous because it mixes with the blood stream.