Medical Resources :: Common Diseases :: Environmental Diseases :: Overview of Lead Poisoning in Chinese Children

Lead Poisoning

• Lead (Pb) is an element found in the earth's crust
• Lead can be found in air, soil, water, food
• Lead is released from the burning of coal inside homes (heating, cooking)
• Lead is emitted from the combustion of lead-containing gasoline
• Lead's toxicity has been known for thousands of years
• Young children are highly susceptible to the harmful effects of lead
• At low levels, lead poisoning causes reductions in IQ and attention span, reading and learning disabilities, hyperactivity, impaired growth, hearing loss, anemia, abdominal pain, constipation
• At high levels, lead poisoning causes coma, convulsions, kidney failure, and even death
• Over the last 20 years the Centers for Disease Control (CDC) has lowered the acceptable level of blood lead for children
• In 1991 the CDC designated a blood lead concentration of greater than or equal to 10 ug/dl as the new definition of childhood lead poisoning
• In 1994 this became the world standard

"Lead Poisoning in Children Adopted from China"

• Aronson et al. Ambulatory Pediatric Association Poster #1381 May 1, 1999
• Method: Retrospective chart review from January 1993 to September 1998
• 301 children adopted from China were tested for lead by venipucture within a month of arrival in the U.S.

Results of Study

• Study done at two international adoption clinics (Winthrop, U. of Minn), and a number of private urban/suburban pediatric practices
• Ages ranged from 1 mo. to 57 mos. with a mean age of 13.6 mos.
• 262 (87%) children had lead levels in the normal range 0-9
• 39 (13.0%) children had lead levels 10 or greater consistent with lead poisoning
• 23 (7.6% of the total) children with lead levels 10-14
• 6 (2.0%) children with lead levels 15-19
• 5 (1.7%) children with lead levels 20-24
• 5 (1.7%) children with lead levels 25-54
• A 14 month old girl with a lead level of 48 was treated with Chemet for 19 days
• After treatment her lead level was initially 20 and now two years later her level is 16
• No sources of lead found in her home
• She has normal development

Winthrop International Adoption Center

• 184 children tested
• 163 (88.6%) children had nl lead 0-9
• 21 (11.4%) children elevated lead levels
• Hunan Province 7
• Jiangxi Province 7
• Guangdong, Fujian, Hubei Provinces each 1 child
• Jiangsu Province 4
• Follow-up of all original 21 girls for elevated lead levels showed that all of the girls had normal levels within a year, except the one child who was treated and two years later still has a level of 16
• Development: 8 (38%) children were referred for Early Intervention which was essentially the same for children with normal lead levels
• 5 (24%) children with elevated lead levels were anemic which actually is about the same as the incidence of anemia in children without elevated lead levels

Lead Poisoning in China

• Mining, smelting, refining and manufacturing (lead-acid batteries, cables, plumbing) release lead into air, water, soil
• Printing houses-major source of lead
• Rural industrialization is encouraged by the Chinese government ("backyard industries")
• Outdated equipment and lack of environmental controls in both urban and rural industries
• Rural and suburban lead emissions may be higher than in urban settings
• Contamination of fresh vegetables, fruits, and rice with lead is inevitable in the countryside

Lead Poisoning in the Chinese Countryside

• Clothes of workers in factories may result in contamination of their homes and poisoning of their children
• Two siblings of a family operating a backyard lead smelter had recurrent abdominal pain and iron deficiency anemia with no response to iron therapy

Lead Poisoning in Chinese Children in the Countryside

• The blood lead levels of these two children were in the high 90s
• All symptoms were markedly improved after two courses of chelation therapy

Childhood lead poisoning in China

• Xiao-ming Shen et al 1996 The Science of the Total Environment: 181, 101-109
• 17 publications in China have reported elevated blood lead levels in children from different areas
• Lead poisoning in China is widely pervasive due to rapid industrialization and the use of lead-containing gasoline

Conclusion

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 that children adopted from China 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 Poisoning in Children Adopted from Abroad, or Lead Exposure in Chinese Children in the Medical Resources/Environmental Diseases section of this site.

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