Editorials

The worldwide problem of lead in petrol Philip J. Landrigan1

The use of lead as a petrol additive has mean blood lead level (6). Similar effects earlier this year, called specifically for the been a catastrophe for public health. were recorded in Western Europe, removal of lead from petrol. This call Leaded petrol has caused more exposure Australia, Canada, New Zealand and resonates with the theme of World Health to lead than any other source worldwide. South Africa (7). In a number of devel- Day 2003, which is healthy environments By contaminating air, dust, soil, drinking- oping countries too, including China, for children. water and food crops, it has caused El Salvador, India, Mexico and Thailand, Precaution is the lesson to be learnt harmfully high human blood lead levels declines in blood lead levels have followed from the history of lead in petrol. The around the world, especially in children (1). the removal of lead from petrol (8). worldwide dissemination of tetraethyl- Tetraethyllead was first added to Nearly 50 nations have now renounced lead is a classic example of our excessive petrol in 1922, to improve engine perfor- the use of lead in petrol, and more are willingness to adopt a promising but mance. Soon after production began in planning such action in the next five years. unproven new technology without heed Bayway, New Jersey, USA, an outbreak of Worldwide, unleaded petrol now to its possible consequences. We made acute neuropsychiatric disease appeared accounts for 80% of total sales (1). This is the same error with chlorofluorocarbon among workers, 80% of whom developed a triumph for public health. (CFCs), and we are at risk of making it convulsions and five died (2). A brief The elegant report from Pakistan in again if we adopt fuel additives containing moratorium was imposed, while plant this issue of the Bulletin (pp. 769–775) manganese, a known neurotoxin. For our conditions were improved. Then, despite describes the current situation in that children’s future, we must do better. n strong public health warnings, production country. On the negative side, the average resumed. By the 1970s, almost all petrol blood lead level among children in 1. Organisation for Economic Cooperation & Devel- Karachi is significantly higher than that opment / United Nations Environment Programme. produced around the world contained Phasing lead out of gasoline: an examination lead. In the United States alone, annual seen today among children in industria- of policy approaches in different countries. Paris: petrol consumption included almost lized countries. This exposure derives OECD; 1999. 200 000 tonnes of lead (3). from multiple sources, and the authors 2. Rosner D, Markowitz G. A ‘gift of God’? The public Lead is toxic to multiple organ have done a superb job of tracing them. health controversy over leaded gasoline during Their work will guide future prevention. the 1920s. American Journal of Public Health systems; even at low levels previously 1985;75:344-52. considered safe, it has been shown through On the positive side, the authors demon- 3. National Academy of Sciences. Lead: airborne lead a series of prospective epidemiological strate that a decline in the use of leaded in perspective. Washington: National Academies studies to produce adverse effects (4). petrol in Pakistan has resulted in declines Press; 1972. Some of these are clinically evident, while in children’s blood lead levels. This success 4. National Academy of Sciences / National Research others are discerned only through special is cause for hope. Council. Measuring lead exposure in infants, children, and other sensitive populations. testing and are thus defined as subclinical. The technology exists to complete the Washington: National Academy Press; 1993. The nervous system of the fetus and transition from leaded to unleaded petrol. 5. Lanphear BP, Dietrich K, Auinger P, Cox C. infant is especially susceptible to lead, The success already achieved attests to Cognitive deficits associated with blood lead which can cross the placenta and penetrate the feasibility of this changeover (1). concentrations <10 mg/dl in US children and the blood-brain barrier. Lead interferes Previously, concerns had been raised that adolescents. Public Health Report 2000; lead must be replaced with benzene, a 115:521-9. with neuronal migration, cell proliferation 6. US Department of Health and Human Services. and synapse formation during critical proven cause of leukaemia. Now, however, Update: blood lead levels — United States, 1991– periods of early vulnerability. The con- it has been established that benzene is 1994. Morbidity and Mortality Weekly Report sequences are loss of intelligence and not necessary (9). Previously too, it had 1997;46:141-5. disruption of behaviour. Because the brain been suggested that leaded petrol was 7. Thomas VM. The elimination of lead in gasoline. needed for the proper operation of certain Annual Review of Energy and the Environment has little capacity for repair, these effects 1995;20:301-24. are permanent and untreatable. The most cars, especially older ones. But an 8. Ruangkanchanasetr S, Suepiantham J. Prevalence recent research indicates that lead can engineering analysis has shown that this and risk factors of high lead level in Bangkok damage the infant brain even at blood claim is not true (10). Moreover, an children. International Conference on Environmen- levels as low as 5 m/dl (5). economic analysis has found that the costs tal Threats to the Health of Children: Hazards of removing lead are generally low — and Vulnerability, Bangkok, Thailand, 2002 These findings, together with data (in conference programme book, unpublished). showing that lead can damage the catalytic less than US$ 0.02 per litre for most 9. Global dimensions of lead poisoning: an initial converters of cars, have triggered strong countries (1). And there are economic analysis. Washington DC: Alliance to End governmental action. Nations around the benefits associated with the protection Childhood Lead Poisoning; 1994. world have begun to ban lead in petrol. of both engines and children against lead. 10. The case for banning lead in gasoline. Washington, Sharp declines in average blood lead levels WHO has been a leader in the global DC: Manufacturers of Emission Controls Associa- tion; 1998. and in the number of persons with elevated effort to remove lead from petrol. The 11. Suk WA. Beyond The Bangkok Statement: Research levels have resulted. In the USA, the Bangkok Declaration (11), unanimously needs to address environmental threats to chil- removal of lead from petrol between 1976 adopted at an international meeting on dren’s health. Environmental Health Perspectives and 1995 resulted in a 90% reduction in children’s environmental health convened 2002;110:A284-6.

1 Mount Sinai School of Medicine, One Gustave L. Levy Place, Box 1057, New York, NY 10029, USA (email: [email protected]). Ref. No. 02-0404

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