Air pollution levels creep up in Delhi
The HinduAir quality in Delhi and its suburbs deteriorated again overnight after a marginal improvement a day ago with forecasts suggesting that a major relief is unlikely in the coming days. The Centre on Saturday removed stringent curbs, including a ban on construction work related to linear projects and the entry of polluting trucks into Delhi in view of a dip in air pollution levels due to favourable wind speed and direction. These measures constitute the final stage -- Stage IV -- of the Centre's air pollution control plan called the Graded Response Action Plan. The Commission for Air Quality Management in National Capital Region and Adjoining Area, a statutory body responsible for formulating strategies to combat pollution in the region, asked Delhi and NCR states to revoke all emergency measures, under which only CNG, electric and BS VI-compliant vehicles from other states are allowed to enter Delhi, with exemptions granted to those involved in essential services. Secondary inorganic aerosols -- particles such as sulfate and nitrate that are formed in the atmosphere due to the interaction of gases and particulate pollutants from sources like power plants, refineries and vehicles -- are the second major contributor to Delhi's foul air, accounting for 30 to 36 per cent of the air pollution in the city over the last few days.