Literature
Clinical Pearls & Morning Reports
Published October 30, 2024
The global burden of disease from lead exposure is staggering. One in three children worldwide — more than 600 million children — have lead poisoning, defined as a blood lead level exceeding 50 µg per liter; 90% of children with lead poisoning live in industrializing countries. Read the NEJM Review Article here.
Clinical Pearls
Q: Where in the body is lead stored?
A: Once absorbed, 95% of retained lead in adults is stored in the skeleton; in children, 70% is stored in the skeleton. Approximately 1% of the total body lead burden is circulating in blood; 99% of lead in blood is found in red cells. The concentration of lead in whole blood — a mixture of newly absorbed lead and remobilized lead from skeletal stores — is the most widely used biomarker of exposure.
Q: Is chronic lead exposure harmful to adults?
A: Lead exposure is a risk factor for chronic kidney disease and preterm births at concentrations commonly found in people today. Studies conducted over the past 40 years have established that chronic, low-level lead poisoning is a major risk factor for cardiovascular disease in adults.
A: Some persons are at increased risk for lead poisoning as compared with the general population. The mouthing behaviors of infants and toddlers put them at greater risk for lead ingestion, and they absorb lead more readily than older children and adults. Toddlers who live in poorly maintained housing built before 1960 are at risk for lead poisoning from ingestion of paint chips and lead-contaminated house dust. Persons who drink tap water from lead service lines or live near airports or other sites that emit lead pollution are also at increased risk for low-level lead poisoning. In the United States, airborne lead concentrations are markedly higher in racially segregated communities than in integrated communities. Workers in smelting, battery recycling, and construction, as well as persons who use firearms or have retained bullet fragments in their bodies, are at increased risk for lead poisoning.
A: Lead is readily absorbed by rapidly growing infants, and absorption can be enhanced in the context of iron or calcium deficiency. Studies conducted over the past 40 years have established that chronic, low-level lead poisoning is a major risk factor for cognitive deficits in children, even at levels previously thought to be safe or innocuous. In 2012, the Centers for Disease Control and Prevention declared that no safe level of lead in children’s blood had been identified. Lead exposure is a risk factor for behavioral conditions, such as attention deficit–hyperactivity disorder. Childhood lead exposure is a risk factor for antisocial behaviors, including those associated with conduct disorder, delinquent behavior, and criminal behavior. Lead exposure early in life may be a risk factor for late-onset Alzheimer’s disease, but the evidence is inconclusive. Lead chelation is effective in reducing the body lead burden, but findings regarding the effects on health outcomes are inconsistent. The inconsistent findings regarding the efficacy of chelation indicate that primary prevention is critical.