Deafening silence

The dangerously high level of benzene in Delhi's air speaks volumes

Published: Friday 31 December 1999

Only silence could save them -- so thought the Delhi Pollution Control Committee (dpcc). When frightening levels of benzene began to be recorded in Delhi by an independent monitoring agency, a lot of care was taken to keep this data under wraps.

Now that the cat is out of the bag, the regulatory authorities are busy finding excuses for having remained quiet. Of course resorting to ambiguous reasoning helps. It is always easy to say that the monitoring showed levels to be so high that they seemed untrue. The authorities should have in any case been spurred into action and warned the public about this threat to their health. Instead, all they did was doubt the accuracy of the methods they had used. There is cause for alarm. Benzene has been linked with leukaemia. The World Health Organisation says that there is no safe level for airborne benzene.

The air was monitored for benzene levels at 180 sites in Delhi by a testing laboratory, sgs India Limited, for the dpcc. The results showed that the levels were as high as 1,762.63 microgramme per cubic metre (g/cum) in a sensitive area like the Hindu Rao Hospital, and more than 4,140.36 g/cum at a residential site, Greater Kailash I.

Reports on high levels of benzene in Delhi's air have been trickling in for some time now. The first report came in 1996 when a Dutch study showed levels 10-12 times higher than the European standard of 10 g/cum and, the second time, when a study conducted by the School of Environmental Sciences in Jawaharlal Nehru University recorded a sharp jump of almost 50 per cent after the complete phase out of leaded petrol in the capital in September 1998.

We already know that benzene content is as high as 3-5 per cent in Indian unleaded petrol as opposed to 1 per cent in the us. But more shocking is the new scientific evidence that even diesel vehicles emit high amounts of benzene. A study by the Institute of Experimental and Clinical Medicine in Estonia, published in the Scandinavian Journal of Work Environment & Health (Vol 24, No 6) shows that particles in diesel exhaust contain benzene in amounts comparable to the total concentrations of carcinogenic polycyclic aromatic hydrocarbons in diesel exhaust. It is feared that the diesel lobby could use this data to obfuscate threat perceptions to health from diesel by blaming it solely on petrol vehicles. It is time the cpcb and the dpcc went public with their information. Hiding data may lead to confusion in the minds of the citizens and allow vested interests to use it to spread disinformation.

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