Environment Minister Prakash Javadekar says there has been a significant reduction in pollution emanating from stubble burning. He said the pollution levels have come down to three to four per cent compared to the earlier levels of 35 to 40. <br />'' <br />'' He was briefing media in New Delhi today after a review meeting with the officials of the pollution affected States. The Minister said discussions were held on the action plans to curb the pollution levels in Delhi and the NCR.<br />'' <br />'' The Minister attributed factors such as garbage, dirt, vehicles and industries to 80 per cent of the pollution. He said Eastern and Western Peripheral Expressways have been constructed, and around 60 thousand vehicles are diverted from the national capital, resulting in a substantial reduction in pollution. <br />'' <br />'' Prakash Javadekar said Bharat standard-six vehicles will ply on Delhi roads from April next year. He said, around 3,000 industries and 2,800 brick klins switched over to using piped natural gas. He said work on generating electricity and making compost from garbage is underway. <br />''