levels of airborne benzene, which is known to be carcinogenic, were found to be alarmingly high at two major junctions at Mumbai, according to a preliminary study by the National Environmental Engineering Research Institute ( neeri ). The monitoring was carried out at the Haji Ali junction, the Worli Naka and a petrol pump on two days in July and August of 1999.

At the Haji Ali junction, benzene levels ranged between 100 parts per billion (ppb) and 660 ppb. At the Worli Naka, the level was between 120 ppb and 320 ppb. At the petrol pump, the levels were between 56 ppb and an amazing 970 ppb.

According to the World Health Organisation, benzene levels in the ambient air should be below 5 ppb. A Mumbai newspaper quoted scientist Anjali Srivastava as saying that about 80 per cent of the airborne benzene is from motor vehicle emissions.