Anti pollution figureheads
• Plants control air pollution by taking in carbon dioxide (CO 2 ) from the atmosphere and releasing oxygen. A peepal tree with a crown spread of 162 sq km releases 1,712 kg of oxygen and absorbs 2,252 kg of CO 2 per hour.
• Trees not only mechanically stop smoke and dust from reaching us, but also act as sinks of many noxious gases, thus purifying the air.
• A 500 metre-wide green area can reduce the concentration of SO 2 by 70 per cent and that of NO 2 by 67 per cent.
• A fully-grown tree can absorb the pollution generated by a car running for 25,000 km.
• If an air mass containing 150 parts per million of ozone were to be suspended over a forest area for eight hours, the vegetation would absorb 80 per cent of the ozone.