despite petrol's benzene content being lowered from 3 per cent to 1 per cent in 2000-2001, there has been no significant effect on the current ambient levels of this carcinogenic chemical.

Benzene levels in air continue to be high according to two recent studies: Central Pollution Control Board's (cpcb's) Highlights 2005 and a Current Science paper (Vol. 91, No. 10, Nov 25, 2006) by scientists of the Nagpur-based National Environmental Engineering Research Institute (neeri).

cpcb's Highlights 2005 shows that the annual maximum concentration of benzene in ambient air in Delhi's Sirifort Area was as high as 17.9 microgramme per cubic metre (