NEW DELHI, January 29: The number of vehicles on Indian roads has almost trebled in the past 10 years, adding to the growing menace of air pollution, warns a study.The total number of registered motor vehicles in the country has increased from 11 million in 1986 to more than 30 million in 1995, of which about 3 per cent is concentrated in 23 metropolitan cities.A report in the `compendium of environmental statistics' published by the statistics wing of the ministry of planning and programme implementation warns that such steep rise in the vehicular traffic would only add to the already high levels of automobile exhausts in the environment. The different factors which add to air pollution by vehicular emissions have been identified as the types of engines used, the age of the vehicles, poor road conditions and congested traffic. The principal vehicular pollutants are carbon monoxide, oxides of nitrogen, hydrocarbons, suspended and particulate matters, a varying amount of sulphur dioxide and leadcompounds.
Among the states, Maharashtra has the highest number of vehicles at more than 36 lakhs followed by Gujarat (about 30.2 lakhs) and Uttar Pradesh (about 25.2 lakhs).In the metros, Bangalore tops the chart with about eight lakh. Mumbai has more than 6.6 lakh vehicles and Calcutta about 5.6 lakh, the report says. The effect of automobile exhausts on human helath is shown in the report by correlating average levels of lead in the blood and the lead content in gasoline.Hydrocarbons present in the exhaust, particularly in vehicles with poor combustion, cause respiratory problems. In urban areas with tall buildings, which act as concrete canyons, and in street crossings, the pollutants from vehicles stay for a much longer period. Pollution also causes photochemical smog.While the permissible limit for lead is two micro gram per 100 millilitre of blood, an average metro citizen has a lead level between three to 82 micro gram per 100 millilitre of blood, the report said.
The petroleum and natural gasministry has already implemented the first phase of introducing petrol with a maximum lead content of 0.15 gms per litre in the four metros Delhi, Calcutta, Mumbai and Chennai.In a comparison between leaded and unleaded petrol-driven vehicles, the report identifies more than half the Fiat and 118-NE unleaded models (with catalytic converters) exceeding the permissible limits.More than 33 per cent of the Contessa and Ambassador models, both with and without converters, exceeded limits while 27 per cent of leaded Maruti vehicles did so.
Copyright © 1998 Indian Express Newspapers (Bombay) Ltd.
