The Economic Survey has expressed concern over air pollution in Delhi with the onset of winter due to various factor. <br/><br/>It has ascribed four main reasons for Delhi's worsening air quality – crop residue, biomass burning, vehicular emissions and re-distributed road dust, industries, power plants and winter temperature inversion, humidity and absence of wind. <br/><br/>It has suggested coordination between agencies and Central and State Governments and sustained civic engagement to address each source problem systematically. <br/><br/>The Survey said, the short-term emergency plan is to be implemented when 24-hourly PM 2.5 exceeds 300 to 400 micro-gram per cubic metre, including imposing heavy penalties on burning of agricultural waste, using satellite-based tools to detect fires, payment of incentives to farmers. <br/><br/>The medium and long-range actions include implementing congestion pricing for vehicles, improving public transport system and expanding modernized bus fleets, phasing out old vehicles and accelerating BS-VI. <br/><br/>The Survey also suggest the use of technology to convert agricultural waste into usable fodder or bio-fuels and provide incentives to shift to non-paddy crops.