Phasing out leaded gasoline will not end lead poisoning in developing countries.

The phaseout of leaded gasoline would be a significant step forward in the reduction of a major source of exposure; however, this undertaking , even if successful, will have limited public health impact if other sources of exposure are not substantially reduced. For instance, in Mexico City, after the introduction of unleaded gasoline in 1990, lead concentrations in air declined from 1.2 pg/m3 to 0.2 pg/m3 in 1993. since 1992, blood lead level in this particular cohort of children has declined at a slower pace, showing concentrations of 9.8 ,ug/dl (3), indicating exposure to other sources. In Caracas, Venezuela, between 1971 and 1993, the lead content in gasoline was reduced from 0.84 to 0.45 g/l. However, during this period the number of vehicles has also grown, tripling gasoline consumption. The net result has been an increase from 3,763 to 5,492 tons/year of lead released into the air (4). While lead in gasoline additives represents only 2.2% of the total global lead use, it may have a disproportionate significance to human health. On one hand, the rapid urbanization experienced by the Latin America and the Caribbean countries, where close to 75% of the population lives in cities, places about 14.5 million children below 2 years of age at a particular risk (5), since the volume of traffic close to home is an important predictor of lead blood levels (6). On the other hand, the use of leaded gasoline is preventing widespread use of catalytic converters in vehicles, therefore contributing to the continuous increase of the already critical levels of other air pollutants. Recent estimates of the use of leaded gasoline in the Americas indicate that approximately 9,000 tons/year of lead are still being added to gasoline. Sixteen countries are marketing gasoline with a maximum lead concentration of 0.8 g/l. Thirteen countries have reduced their gasoline lead content to about 0.4 g/l, and only six countries have phased out leaded gasoline altogether (7). the heads of governments agreed to develop and implement national action plans to phase out lead in gasoline. More recently, in April 1995, the United Nations Commission on Sustainable Development made recommendations to "all interested countries to develop action plans with a view to phase out or reduce the use of lead in gasoline." The commission also encouraged countries to share their knowledge and experience in the reduction or phasing out of leaded gasoline, including the use of biomass …