Blood lead levels below 5 micrograms per deciliter (µg/dL) (50 parts per billion [ppb]), which were thought to be safe or innocuous, have been shown to be a risk factor for diminished intellectual and academic abilities, higher rates of attention-deficit/hyperactivity disorder and lower birthweight in children. An updated AAP policy Prevention of Childhood Lead Toxicity, http://dx.doi.org/10.1542/peds.2016-1493, reflects the recognition that there is no safe level of lead in children’s blood and calls for renewed effort to further reduce children’s exposure to lead.
The impact
About 2.5% of U.S. preschoolers have a blood lead concentration ≥5 µg/dL, which represents about 535,000 children ages 1-5 years.
Children who have blood lead concentrations ≥5 µg/dL will, on average, experience an IQ deficit of five to six points, after adjusting for other factors. Some have argued that a five-point reduction in IQ is of little consequence. However, a five-point shift in the mean population IQ of American children would increase the number of children having an IQ lower than 70 from 6 million to 9.4 million (see link to video in resource box).
Reducing sources
Primary prevention — reducing or eliminating the myriad sources of lead in the environment of children before exposure occurs — is the most reliable and cost-effective way to protect children from lead toxicity, according to the policy from the AAP Council on Environmental Health. No treatments are known to reverse the developmental effects of low-level lead toxicity.
Pediatricians and other health professionals who care for children and their families are in a key position to advocate for public health efforts to screen children’s environments and reduce sources of lead before they are exposed. The updated policy outlines recommendations for government and for physicians and public health officials.
Children who lived in older housing units are at higher risk for having a blood lead concentration >5 µg/dL; 15% of U.S. children who lived in housing units built before 1950 had a blood lead concentration ≥5 µg/dL compared with 2.1% of children who lived in housing units built after 1978. Some of the most important sources of lead in children’s environments include lead-based paint, lead-contaminated soil, dust and water, as well as imported ceramics, aviation gas from regional airports, industries and consumer products.
For every $1 invested to reduce lead hazards in housing, society would benefit by an estimated $17 to $221 — a cost-benefit ratio that is comparable to that of childhood vaccines.
Education, counseling critical
In the primary care office, prevention begins with education and counseling about reducing children’s exposure. Parents who live in older housing should be advised to screen their homes for lead hazards before a child is born or during the newborn period so that lead hazards can be identified and eliminated. Housing built before 1960 should be screened for lead hazards, especially if it has undergone repair and renovation or if it is poorly maintained.
Lead-safe work practices and collecting dust clearance levels after the work is completed are essential to control lead hazards; if renovation or abatement is done wrong, it can increase the risk of a child developing lead poisoning.
Screening strategies
Pediatricians and other primary care providers should screen children in the first three years of life to determine if a blood lead test is indicated. A blood lead test should be considered for children who are younger than 3 years if they live in a house with an identified lead hazard or that was built before 1960, especially if it is in poor repair or was renovated in the past six months.
Pediatricians and hospitals should use labs that provide blood lead tests with laboratory error of ±2 µg/dL; labs should report results down to 1 µg/dL to enhance case management and surveillance.
The Academy has adopted a blood lead level of ≥5 µg/dL as an action level for case management. Local or state health departments should conduct environmental investigations to identify sources of lead exposure for a child who has a blood lead concentration ≥5 µg/dL. In many cases, however, sources of lead become evident by taking a careful history.
Pediatricians should be familiar with collection and interpretation of reports about lead hazards in house dust, soil, paint and water, or refer families to another pediatrician, health care provider or specialist who is familiar with these tools.
Recommendations for pediatricians
- Screen children and work with public health officials to conduct surveys of blood lead concentrations among children in their states or communities at regular intervals to identify trends in blood lead concentrations. Periodic surveying is especially important for children who live in highly contaminated communities.
- Routinely recommend individual environmental assessments of older housing.
- Advocate for strict legal standards based on empirical data that regulate allowable levels of lead in air, water, soil, house dust and consumer products.
- Be familiar with federal, state, local and professional recommendations or requirements for screening children and pregnant women for lead poisoning.
- Test asymptomatic children for elevated blood lead concentrations according to federal, local and state requirements. Immigrant, refugee and internationally adopted children also should be tested when they arrive in the U.S.
- Conduct targeted screening for elevated blood lead concentrations in children ages 12-24 months if they live in communities or census block groups with 25% or more of housing built before 1960 or a prevalence of children’s blood lead concentrations ≥5 µg/dL (≥50 ppb) of 5% or greater.
- Test children if they live in or visit a home or child care facility with an identified lead hazard or a home built before 1960 that is in poor repair or was renovated in the past six months.
Great progress has been made in reducing childhood lead poisoning, but too many children continue to be exposed to levels shown to be harmful.
Dr. Lanphear, lead author of the policy, is a former member of the AAP Council on Environmental Health Executive Committee.
