EWG

Sign up to receive email updates, action alerts, health tips, promotions to support our work and more from EWG. You can opt-out at any time. [Privacy]

 

Research shows greater risk to children

May 3, 2004

Lead Astray: Research shows greater risk to children

Although average levels of lead in the blood of America’s children have dropped dramatically in the last 20 years, lead paint remains a top environmental threat to children’s health. For young children, there is no known safe level of exposure to lead; even low levels can cause reduced IQ and attention span, learning disabilities, and a wide range of other health effects. Lead is most dangerous to children under six, whose brains and nervous systems are still developing and whose outdoor activities and tendency to put things in their mouths can expose them to a disproportionate amount of lead in soil, paint and dust.

CDC estimates that nationwide, about 2.2 percent of children ages 1 through 5 have harmful levels of lead in their blood (CDC 2003). But national averages mask the severity of the problem in many communities. CDC’s testing shows that children from poor families are eight times more likely to be lead poisoned than children from higher-income families. Nationally, non-Hispanic Black children are five times more likely, and Mexican-Americans almost twice as likely, to be poisoned than non-Hispanic White children (CDC 1997).

A growing body of science indicates that levels of lead thought to be safe by government health officials are, in fact, quite hazardous. Research results published in the New England Journal of Medicine in April, 2003 showed an average IQ decline of 7.4 points for children with blood lead levels currently deemed safe — 10 micrograms of lead per deciliter of blood (10 µg/dL) — when compared to children with blood lead levels less than 1 (Canfield et al. 2003). The estimate in EWG’s investigation of 19,000 lead poisoned children in Ohio considers only children with blood lead over 10 µg/dL. If the effects of lead poisoning at lower levels were included, thousands of additional children across Ohio could be affected.

The state’s failure to identify the overwhelming majority of children with dangerous levels of lead in their blood hampers the development of an effective statewide program to reduce lead poisoning. As a result, despite significant advances in the diagnosis and prevention of lead poisoning, a generation of high-risk Ohio children have suffered needlessly.

This tragedy is intolerable, not only for its effect on public health but on other areas of public policy. Continuing to allow thousands of children to suffer from lead poisoning has serious consequences for the future of Ohio’s schools, health care, economy and criminal justice system. The state could make no better investment than fully funding and enforcing the testing requirements in the new state lead law, HB 248, which took effect on April 1, 2004, and mandates testing for children in state-designated high-risk ZIP codes.

A slow poisoning

There is no disagreement about the adverse health effects of lead. It is a highly toxic heavy metal that can cause permanent neurological and behavioral problems and affects virtually every system in the body (CDC 1991). Young children are particularly susceptible to the effects of lead because they explore their world with hands and mouth, increasing the chances for ingestion. In addition, a child or fetus absorbs up to four times more lead than an adult (DHS 1998a). Adults typically absorb 10 to 15 percent of ingested lead, but for children and pregnant women, it's as high as 50 percent (Royce and Needleman 1985).

Lead is a widely acknowledged developmental and reproductive toxin because of its potential for causing infertility and spontaneous abortion in adults and developmental defects in children. Some studies also suggest a relationship between rising blood lead levels and pre-term delivery, low birth weight and fetal growth retardation (Schettler et al 1998). Lead can affect children at extremely low levels, and there is no evidence of a threshold dose below which developmental effects do not occur. Levels as low as 10 micrograms per deciliter of blood (µg/dL) — currently considered the threshold for elevated blood lead level — have been associated with decreased intelligence and impaired neurobehavioral development (CDC 1994). Consumption of as little as 10 micrograms — one-millionth of a gram, which is 1/28 of an ounce — of lead a day can poison a child.

Since lead has been removed from gasoline and food containers, its most common source is lead-based house paint. About 10 billion pounds of lead paint were used in the United States between its introduction in 1889 and the imposition of federal restrictions in 1970 — 61 years after France, 48 years after Australia and 44 years after Great Britain. House dust is often contaminated by lead-based paint that is peeling or deteriorating, or is disturbed during renovation or the preparation of painted surfaces for repainting without proper safeguards. Soil contamination can be traced to deteriorating exterior paint or the past widespread use of leaded gasoline.

Lead was a major ingredient in most interior and exterior oil house paint before 1950 and was still used in some paints until 1978, when the residential use of lead paint was banned. Other sources of lead in a child's environment include lead-contaminated drinking water, lead-contaminated soil, imported ceramic tableware with lead glaze, old and imported toys or furniture painted with lead-based paint, the clothing of parents whose work or hobby involves high levels of lead, and even home remedies used by some ethnic groups. In Ohio, state officials estimate that about one-sixth of lead-poisoned children were exposed through “contact with ethnically associated products such as home remedies, cosmetics, ceramic pottery, cookware and food” (DHS 1999).

Lead Poisoning in Communities of Color

Communities of color and low-income communities bear a much greater burden of lead poisoning. In 1997, the CDC's National Health and Nutrition Examination Survey (NHANES) found that while one to two percent of middle- and high- income children in the U.S. have lead poisoning, 8 percent of low-income children do. On average, low-income children have blood lead levels twice that of high-income children — 3.8 µg/dL vs. 1.9 µg/dL. Similarly, 11.2 percent of non-Hispanic Black children and 4 percent of Mexican-American children nationwide have lead poisoning, compared to 2.3 percent of Non-Hispanic White children (The CDC's national figures do not account for Latinos of other ancestries.) (CDC 1997).

There are no overt symptoms of lead poisoning. The only way to identify and treat lead poisoned children is through early and periodic testing, diagnosis and treatment. In 1991, the CDC recommended that all young children get blood lead tests. At that time, one in six children in the U.S., and as many as 67 percent of black inner-city children, had lead poisoning high enough to cause significant impairment to their neurological development (NAACP 1991).

References

Canfield, R.L., Henderson, C.R., et. al. 2003. "Intellectual Impairment in Children with Blood Lead Concentrations below 10 µg per Decileter." New England Journal of Medicine 348(16): 1517-1526. April 17, 2003.

Centers for Disease Control and Prevention (CDC). 1991. "Preventing Lead Poisoning in Young Children: A statement by the Centers for Disease Control and Prevention." US Dept. of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention. http://www.cdc.gov/nceh/pubcatns/1994/cdc/books/plpsn/plpsn0-3.htm

Centers for Disease Control and Prevention (CDC). 1994. "Data to Action: CDCÕs Public Health Surveillance for Woman, Infants and Children, Maternal and Child Health Monograph." United States Centers for Disease Control, Washington, DC. http://www.cdc.gov/nccdphp/drh/datoact/

Centers for Disease Control and Prevention (CDC). 1997. "Update: Blood Lead Levels - United States 1991-1994." Morbidity and Mortality Weekly Report 46(07): 141-146.

Centers for Disease Control and Prevention (CDC). 2003. "Surveillance for Elevated Blood Lead Levels Among Children - United States, 1997 - 2001." Morbidity and Mortality Weekly Report 52(SS-10) September 12, 2003.

Department of Health Services (DHS). 1998A. Lead Hazards in California's Public Elementary Schools and Child Care Facilities. Department of Health Services, Childhood Lead Poisoning Prevention Branch, Emeryville, CA citing Jacobs, DE. 1995. "Lead-based Paint As A Major Source of Childhood Lead Poisoning: A Review of the Evidence," In, Lead in Paint, Soil and Dust: Health Risks, Exposure Studies, Control Measures and Quality Assurance. ASTM STP 1226. Ed. M E Beard SC Allen Iske. Philadelphia, ASTM.

Department of Health Services (DHS). 1999. Attachment 1. "Summary of the [Science and Policy Advisory Panel] Recommendations [on screening]." In, grant proposal submitted by the Department of Health Services and the Public Health Institute to the Centers for Disease Control and Prevention March 31, 1999.

NAACP. 1991. "Stipulated Voluntary Dismissal." Filed in the U.S. District Court of California, San Francisco, Nov 1. CIV No. C-90-3620 EFL.

Royce, S. and H. Needleman, eds. 1985. "Case Studies in Environmental Medicine: Lead Toxicity." Agency for Toxic Substances and Disease Registry.

Schettler, T et al. 1998. "Generations at Risk: How Environmental Toxicants May Affect Reproductive Health In California." CALPIRG and PSR citing Agency for Toxic Substances and Disease Registry. Toxicological Profile for Lead. Atlanta, GA: US Dept. of Health and Human Services, ATSDR, April, 1993 and McMichael, A et al. 1986. "The Port Pirie Study: Maternal Blood Lead and Pregnancy Outcome." J Epi Comm Health 40:18-25.

Office of Ohio Health Plans (OHP), Ohio Medicaid Report, January 2004.