Lead pollution by gasoline - a persisting problem

Background:
While most industrial nations have abandoned or at least restricted the use of leaded gasoline this is not the case for all parts of Asia and Africa.

Tetraethyllead has been added to gasoline in the past and still is in some countries as an anti-knock agent. Lead emitted via vehicle exhaust is widely distributed into the environment and can be absorbed in the human body by inhalation and ingestion from a variety of sources such as contaminated air and water, soil, and food.

Fig. 1: Lead tetraethyl (left) is a lead atom bonded to a tetrahedral arrangment of ethyl groups. Thus, the molecule can be thought of as a metal atom surrounded by a hydrocarbon cage. The C-Pb bond is quite weak, and in the hot environment of an internal combustion engine it fragments producing lead and C2H5 radicals which can help terminate the combustion process by radical reactions.

Exposure to lead can affect the central nervous system and irreversibly affect cognitive performance during childhood. Lead is also discussed to be a toxin influencing human habits enhancing the rate of criminal acts. It is therefore urgent to phase out the use of this anti-knock agent with high priority. Unfortunately even after phasing-out the use of tetraethyl-lead in gasoline, lead contamination of the environment will persist for a long time.

Using lead isotopic signatures, speciation analysis is able to identify the sources and their contribution to lead contamination in humans and their environment.
 

The actual study
Researchers in Beijing have carried out a meta-analysis of AAS and ICP-MS results published during 1994-2004 mainly in Chinese journals to obtain a countrywide picture of how the level of lead in children's blood is changing and how their exposure to this toxic element effects their live. Perhaps predictably from earlier studies, the team found that those children living in urban or industrial regions had much higher levels of lead than those living in rural areas. The figures they reviewed also contrast sharply with the children's western counterparts who have much lower lead levels on average. The issue is a matter of significant public health importance for China, the researchers say.

Shunqin Wang and Jinliang Zhang of the Department of Occupational & Environmental Health Science, at Peking University Health Science Center, in Beijing point out that childhood blood lead warning levels have been set at 100 micrograms per litre. Unfortunately, in some regions where environmental lead levels are highest children may suffer chronic exposure at levels much higher than this. No single study of blood lead levels in children in China has provided a clear picture despite this being a significant problem given that more than a fifth of the population, almost 400 million, are children. In order to address this issue, Wang and colleagues reviewed and analysed data covering the decade 1994-2004. They hoped to identify risk factors for childhood lead poisoning with a view to improving disease control and prevention.

Their analysis comes to the perhaps obvious conclusion that the use of lead in motor fuels and paints should be phased out or reduced in China as elsewhere in the world. Lead control of industrial emissions must also be reduced. At the same time, childhood hygiene habits must be improved and children monitored more closely.


The new Chinese study

Shunqin Wang, Jinliang Zhang, Blood lead levels in children, China, Environ. Res. (U.S.A), 101/3 (2006) 412-418. DOI:10.1016/j.envres.2005.11.007



Related studies:

About lead in the blood of children in different parts of the world

Vikram Nichani, Wan-I Li, Mary Alice Smith, Gary Noonan, Milind Kulkarni,
Mohan Kodavor, Luke P. Naeher, Blood lead levels in children after phase-out of leaded gasoline in Bombay, India, Sci. Total Environ., 363/1-3 (2006) 95-106. DOI: 10.1016/j.scitotenv.2005.06.033

S.A. Boseila, A.A. Gabr, I.A. Hakim, Blood Lead Levels in Egyptian Children: Influence of Social and Environmental Factors, Am. J. Public Health, 94/1 (2004) 47-49. DOI: 10.2105/AJPH.94.1.47

Offie Porat Soldin, Brian Hanak, Steven J. Soldin, Blood lead concentrations in children: new ranges, Clin. Chim. Acta, 327/1-2 (2003) 109-113. DOI: 10.1016/S0009-8981(02)00333-9

 R. Kurkjian, A.R. Flegal, Isotopic evidence of the persistent dominance of blood lead concentrations by previous gasoline lead emissions in Yerevan, Armenia, Environ. Res. (U.S.A), 93 (2003) 308-315. DOI: 10.1016/S0013-9351(03)00066-5

U. Stromberg, T. Lundh, A. Schutz, S. Skerfving, Yearly measurements of blood lead in Swedish children since 1978: an update focusing on the petrol lead free period 1995-2001, Occup. Environ. Med., 60/5 (2003) 370-372. DOI: 10.1136/oem.60.5.370

C. Yan, S. Wu, X. Shen, Y. Zhang, F. Jiang, J. Yin, The trends of changes in children's blood lead levels since the introduction of lead free gasoline in Shanghai, Zhonghua Liu Xing Bing Xue Za Zhi, 23 (2002) 172-174

M. Wilhelm, A. Pesch, U. Rostek, Jutta Begerow, N. Schmitz, H. Idel, U. Ranft, Concentrations of lead in blood, hair and saliva of German children living in three different areas of traffic density, Sci. Total Environ., 297/1-3 (2002) 109-118. DOI: 10.1016/S0048-9697(02)00101-8

R.M. Tripathi, R. Raghunath, S. Sadasivan and V.D. Puranik, Atmospheric lead as indicator of children's blood lead in Mumbai India, J. Phys. IV France  107 (2003) 1317. DOI: 10.1051/jp4:20030543

R. Espinoza, M. Hernandez-Avila, J. Narcisco, C. Castanaga, S. Moscoso, G.
Ortiz, L. Carbajal, S. Wegner, G. Noonan, Determinants of blood-lead levels in children in Callao and Lima metropolitan area, Salud Publica Mex., 45/S.2 (2003) S209-219. pdf available at: http://www.insp.mx/salud/45/45s2_5.pdf

R.M. Tripathi, Radha Raghunath, A. Vinod Kumar, V.N. Sastry, S. Sadasivan, Atmospheric and children's blood lead as indicators of vehicular traffic and other emission sources in Mumbai, India, Sci. Total Environ., 267/1-3 (2001) 101-108. DOI: 10.1016/S0048-9697(00)00770-1

Stephen T. Wang, S. Pizzolato, Helen P. Demshar, L.F. Smith, Decline in blood lead in Ontario children correlated to decreasing consumption of leaded gasoline, Clin. Chem. (Winston-Salem, N.C.), 43/7 (1997) 1251-1252. DOI: 10.1093/clinchem/43.7.1251

J. Nriagu, C.C. Jinabhai, R. Naidoo, A. Coutsoudis, Lead poisoning of children in Africa, II. Kwazulu/Natal, South Africa, Sci. Total Environ., 197/1-3 (1997) 1-11. DOI: 10.1016/S0048-9697(96)05407-1

J. Nriagu, N.T. Oleru, C. Cudjoe, A. Chine, Lead poisoning of children in Africa, III. Kaduna, Nigeria, Sci. Total Environ., 197/1-3 (1997) 13-29. DOI: 10.1016/S0048-9697(96)05408-3

H.T. Delves, S.J. Diaper, S. Oppert, P. Prescott-Clarke, W. Dong, H. Colhoun, D. Gompertz, Blood lead concentrations in United Kingdom have fallen substantially since 1984, Br. Med. J., 313 (1996) 883-884. DOI: 10.1136/bmj.313.7061.883d

U. Strömberg, A. Schütz, S. Skerfving, Substantial decrease of blood lead in Swedish children, 1978-94, associated with petrol lead, Occup. Environ. Med., 52 (1995) 764-769. DOI: 10.1136/oem.52.11.764

J.L. Pirkle, D.J. Brody, E.W. Gunter, The decline in blood lead levels in the United States: the National Health and Nutrition Examination Surveys (NHANES), J. Am. Med. Assoc., 272 (1994) 284-291. DOI: 10.1001/jama.1994.03520040046039



About the history of leaded gasoline:

William Kovarik, Ethyl-leaded Gasoline: How a Classic Occupational Disease Became an International Public Health Disaster, Int. J. Occup. Environ. Health, 11 (2005) 384-397. DOI: 10.1179/oeh.2005.11.4.384

Valerie M. Thomas, Robert H. Socolow, James J. Fanelli, Thomas G. Spiro, Effects of Reducing Lead in Gasoline: An Analysis of the International Experience, Environ. Sci. Technol., 33/22 (1999) 3942-3948. DOI: 10.1021/es990231+



About the toxicity of lead in childhood

Richard L. Canfield, Charles R. Henderson, Jr., Deborah A. Cory-Slechta, Christopher Cox, Todd A. Jusko, Bruce P. Lanphear, Intellectual Impairment in Children with Blood Lead Concentrations below 10 µg per Deciliter, N. Engl. J. Med., 348 (2003) 1517-1526. DOI: 10.1056/NEJMoa022848

D.C. Bellinger, H.L. Needleman, A.N. Eden, M.T. Donohoe, R.L. Canfield, C.R. Henderson, B.P. Lanphear, Intellectual Impairment and Blood Lead Levels, N. Engl. J. Med., 349 (2003) 500-502.
Shilu Tong, Peter A. Baghurst, Michael G. Sawyer, Jane Burns, Anthony J. McMichael, Declining Blood Lead Levels and Changes in Cognitive Function During Childhood, J. Am. Med. Assoc., 280/22 (1998) 1915-1919. DOI: 10.1001/jama.280.22.1915

H.L. Needleman, J.A. Riess, M.J. Tobin, G.E.  Biesecker, J.B. Greenhouse, Bone lead levels and delinquent behavior, J. Am. Med. Assoc., 275 (1996) 363-369. DOI: 10.1001/jama.1996.03530290033034

Sourcing lead by isotope ratio analysis

C. Cloquet, J. Carignan, G. Libourel, T. Sterckeman, E. Perdrix, Tracing Source Pollution in Soils Using Cadmium and Lead Isotopes, Environ. Sci. Technol., 40/8 (2006) 2525-2530. DOI: 10.1021/es052232+

William I. Manton, Carol R. Angle, Kaye L. Stanek Krogstrand, Origin of Lead in the United States Diet, Environ. Sci. Technol., 39/22 (2005) 8995-9000. DOI: 10.1021/es051145e

D.J. Bellis, K. Satake, M. Inagaki, J. Zeng, T. Oizumi, Seasonal and long-term change in lead deposition in central Japan: evidence for atmospheric transport from continental Asia, Sci. Total Environ., 341/1-3 (2005) 149-158. DOI: 10.1016/j.scitotenv.2004.09.038

Madhu Chaudhary-Webb, Daniel C. Paschal, Isabelle Romieu, Bill Ting, Crawford Elliot, Harry Hopkins, Luz Helena Sanín, Mahamad A. Ghazi, Determining lead sources in Mexico using the lead isotope ratio, Salud Publica Mex. (Engl. Ed.), 45/S.2 (2003) S183-S188. pdf available at: http://www.insp.mx/salud/45/45s2_1.pdf

Martin Novák, Simon Emmanuel, Melanie A. Vile, Yigal Erel, Alain Véron, Tomás Paces, R. Kelman Wieder, Mirko Vanecek, Markéta Stepánová, Eva Bízová, Jan Hovorka, Origin of Lead in Eight Central European Peat Bogs Determined from Isotope Ratios, Strengths, and Operation Times of Regional Pollution Sources, Environ. Sci. Technol., 37/3 (2003) 437-445.
DOI: 10.1021/es0200387

Related Information

University of Bristol: More about petrol additives. 
CDC: National Childhood Blood Lead Surveillance Data
Bill Kovarik: How a Classic Occupational Disease Became an International Public Health Disaster
Simon Cotton, Uppingham School, Rutland: Lead TetraEthyl and MTBE - Petrol Additives
Worlatlas: Countries that still use leaded gasoline
Bill Kovarik: Charles F. Kettering and the 1921 Discovery of Tetraethyl Lead In the Context of Technological Alternatives
The Conversation Dec 9, 2021: A century of tragedy: How the car and gas industry knew about the health risks of leaded fuel but sold it for 100 years anyway

Related EVISA News

November 16, 2004: Tetraethyllead in Gasoline - Soon a problem of the past ?



last time modified: March 7, 2024