What is lead poisoning and why is it a threat to the health of growing children? Lead is a neurotoxin that can cause brain damage. It can also damage bones, interfere with growth, exacerbate anemia, and affect kidney function. Children are particularly vulnerable to the harmful affects of lead poisoning because the brain grows so rapidly in childhood. Even very low levels of lead can interfere with children's brain development, affecting their behavior and cognitive abilities. The symptoms of lead poisoning are very subtle and non-specific: constipation, irritability, moodiness, learning problems, and in more serious cases, seizures. The sources of lead in countries outside the U.S. are lead-containing gasoline, emissions from smelting, mining, and other industrial operations, and coal burning. Coal, one of China's major fuel sources, is a major source of lead poisoning in China. It is burned indoors for cooking and heating in many parts of China, so suburban and rural levels of lead exposure can be just as high as in highly polluted urban areas, especially in the winter. With the Clean Air Acts of 1970, 1977 in the U.S., there was an amazing diminution of lead in the environment.
Despite immense improvements since the 1970s, lead poisoning remains the number one environmental health problem in the United States, according to the Yale Lead Program. Dwellings built before 1980 may contain lead paint, and prior use of lead paint and leaded gasoline has left soil and house dust contaminated. The risk of lead poisoning in the U.S. is strongly linked to poverty and old housing. Unfortunately, with limited regulation of environmental toxins all over the world, especially in China, lead poisoning is still a serious health concern for children. Sometimes food can be contaminated with lead dust, and even some Chinese herbal medicines, art objects, and paint have high lead content; parents who work in factories where lead dust contaminates their clothing exposes children to lead in the home environment.
There have been at least seventeen scientific publications which have reported elevated blood lead levels in children from different areas of China. "Childhood lead poisoning in China" published in 1996 in the The Science of the Total Environment, is a comprehensive review of the lead problem in China, written by Chinese physicians from the Shanghai Institute for Pediatric Research. Retrospective pilot studies conducted in Shanghai, Shenyang, Fuzhou, and Beijing evaluated the health effects of childhood lead poisoning and revealed deficits in cognitive abilities (IQ), neurobehavioral development and physical growth.
In a retrospective chart review from January 1993 to September 1998, 301 children adopted from China were tested for lead by venipuncture (blood drawn from a vein) within one month of arrival in the U.S. at two international clinics, Winthrop-University Hospital's International Adoption Medical Consultation Services in Mineola, New York, the University of Minnesota International Adoption Clinic in Minneapolis, Minnesota and a number of private urban/suburban pediatric practices. The ages ranged from one month to fifty-seven months. The mean age was 13.6 months. Two hundred and sixty-two (87%) children had lead levels in the normal range 0-9. Thirty-nine (13.0%) children had lead levels 10 or greater consistent with lead poisoning. Twenty-three (7.6% of the total) children had lead levels in the 10-14 range. Six (2.0%) children had lead levels in the 15-19 range. Five (1.7%) children had lead levels in the 20-24 range. Five (1.7%) children had lead levels in the 25-54 range.
A 14 month old girl with a lead level of forty-eight was treated with a medication by mouth called Chemet for 19 days. After treatment her lead level was initially 20 and 12 months after treatment, her level was 24. No sources of lead were found in her home. She remains healthy and developmentally normal.
Recently, the Centers for Disease Control and Prevention contacted 12 international adoption medical specialists identified from the Joint Council on International Children's Services, and 2 collaborating medical specialists. Of the 14 reporting sites, elevated blood lead ranged from 1% to 13% among Chinese adopted children and ranged from 1% to 5% among Russian adopted children.
As lead poisoning in children significantly decreases in the U.S., there may be a lessening awareness of the threat of lead poisoning. It is imperative that pediatricians be alerted to the fact that children adopted from China and less commonly, Russia and other developing nations, are at risk for lead poisoning and should be screened during their initial health assessment when they first arrive in the U.S.
For more information about lead poisoning, read, Lead Exposure in Chinese Children, or Overview of Lead Poisoning in Chinese Children in the Medical Resources/Environmental Diseases section of this site.back to top
American Academy of Pediatrics. Screening for Elevated Blood Lead Levels. Pediatrics. 1998; 101: 1072-1078.
Aronson JE, Johnson DE, Hostetter MK, et al. Lead Poisoning in Children Adopted from China. Ambulatory Pediatric Association. Pediatric Academic Society's Meeting. San Francisco, California. Abstract #45, May 1999.
Aronson JE. Why is Lead a Problem? International Adoption and Health. The Yale-China Review. 1998; 6: no.1, 30-31.
Morbidity and Mortality Weekly Report. Elevated Blood Lead Levels Among Internationally Adopted Children. Pending publication.
Rubin C, Esteban E, Jones R. Childhood Lead Poisoning in Russia: A Site-Specific Pediatric Blood Lead Evaluation. Int J occup EnvironHealth. 1997; 3: 241-248.
Shen A, Rosen JF, guo D, Wu S et al. Childhood Lead Poisoning in China. The Science of the Total Environment. 1996; 181: 101-109.back to top
|This page last updated September 17, 2003 6:37 PM EST|