New Delhi: Delhi's air quality saw an improvement today, shifting from 'severe' to 'very poor,' prompting the government to ease pollution restrictions and permit the entry of diesel trucks into the national capital. The positive change in air quality was attributed to an increase in wind speed. At 4 pm, the air quality index stood at 317, an improvement from 405 recorded on the previous day. Neighboring cities such as Ghaziabad (274), Gurugram (346), Greater Noida (258), Noida (285), and Faridabad (328) also reported "very poor" to "severe" air quality levels today. Following the notable improvement in air quality, the Commission for Air Quality Management (CAQM) lifted the Stage-IV restrictions under the Graded Response Action Plan (GRAP) in Delhi. However, anti-pollution measures under Stage I to Stage III of GRAP will remain in effect, as stated in a release by CAQM. Stage IV restrictions, implemented on November 5, included a ban on all diesel four-wheelers, except those compliant with BS-VI emission norms. Additionally, all Delhi-registered diesel medium and heavy goods vehicles, except those used for essential or emergency services, were prohibited from operating in the national capital. With the easing of restrictions, trucks are now allowed to enter Delhi. A recent joint project by the Delhi government and the Indian Institute of Technology (IIT), Kanpur, revealed that vehicular emissions contributed to approximately 45 percent of the city's air pollution on Friday. This percentage is expected to decrease to 38 percent on Saturday. Secondary inorganic aerosols, which include particles like sulfate and nitrate formed in the atmosphere due to the interaction of gases and particulate pollutants from sources such as power plants, refineries, and vehicles, emerged as the second major contributor to Delhi's air pollution, accounting for 19 to 36 percent over the past few days. Massive Turnout at ‘Vikas Kranti’ Rally in Hoshiarpur: CM Bhagwant Mann and CM Arvind Kejriwal Unveil Developmental Projects Himanta Biswa Sarma's Bold Assertion of Hindu Politics Why 'Dry Day' in Delhi on World Cup Final? All liquor shops ordered to remain closed