Lead decline in the Indian environment resulting from the petrol-lead phase-out programme.

Recently, the lead content of various environmental components has decreased in response to replacement of leaded petrol by unleaded petrol. In India, 15 research studies are here assessed with respect to lead concentrations in various environmental components during the leaded petrol phase (before 1996), the transitional phase (1996-2000) and the unleaded petrol phase (2000 onwards). The Ganga River Water exhibited a decrease in lead concentration from 18.0 microg/l in 1988 to 3.1 microg/l in 2001. In Lucknow urban centre, mean lead concentrations in the urban air decreased from 1.6 microg/m(3) in 1994 to 0.2 microg/m(3) in 2002. Lead concentrations in Dalbergia sissoo tree leaves also decreased from 18.7 microg/g dry wt. in 1994 to 8.3 microg/g dry wt. in 2004. Mean blood-lead levels of children from Mumbai, Chennai, Bangalore, Amritsar and Lucknow urban centres have fallen from 18.1 microg/dl in the leaded petrol phase to 12.1 microg/dl in the unleaded petrol phase. The petrol-lead phase-out effort in India has reduced lead concentrations in the various environmental components after 2000. It will help to reduce the exposure of millions of people to environmental lead.