From the Guidelines
Normal serum lead levels for a child with no risk factors should be less than 5 micrograms per deciliter (μg/dL). This is the reference level at which public health actions are recommended, according to current guidelines from the American Academy of Pediatrics 1. Children's blood lead levels should ideally be as low as possible, as there is no known safe blood lead level in children. Even low levels of lead in blood have been shown to affect IQ, ability to pay attention, and academic achievement. Lead exposure occurs primarily through ingestion or inhalation, with common sources including lead-based paint in older homes, contaminated soil, certain consumer products, and some types of food and water. The body absorbs lead more readily in children than adults, and their developing nervous systems are more vulnerable to its toxic effects.
Some key points to consider:
- The geometric mean blood lead concentration for US children 1–5 years old is less than 2 μg/dL, and only 2.5% have a blood lead concentration of 5 μg/dL or higher 1.
- The Centers for Disease Control and Prevention (CDC) has defined the blood lead level that should prompt public health actions as 5 μg/dL, which is lower than the previous threshold of 10 μg/dL 1.
- Regular screening for lead exposure is recommended for children at higher risk, but even those without obvious risk factors should maintain levels below 5 μg/dL for optimal health and development.
- It is essential to provide anticipatory guidance about common sources of environmental lead exposure and to perform routine assessment of nutrition and physical and mental development, as well as assess risk factors for iron deficiency 1.
From the Research
Normal Serum Lead Levels in Children
- The Centers for Disease Control and Prevention (CDC) has set a threshold of concern for low-level lead toxicity at a blood lead level of 10 micrograms per dL (0.48 mumol per L) 2.
- However, more recent studies suggest that blood lead levels of less than 5 µg per dL are associated with impairments in neurocognitive and behavioral development that are irreversible 3.
- There is no specific mention of a "normal" serum lead level in the provided studies, but it can be inferred that levels below 5 µg per dL are considered desirable.
- The CDC recommends screening all Medicaid-eligible children at 12 months and again at 24 months, or at least once between 36 and 72 months if not previously screened, to identify children with elevated blood lead levels 3.
Risk Factors and Screening Guidelines
- Risk factors for lead poisoning include age younger than five years, low socioeconomic status, living in housing built before 1978, and use of imported food, medicines, and pottery 3.
- The CDC recommends universal screening in areas where more than 27% of the housing was built before 1950, or where at least 12% of children 12 to 36 months of age have blood lead levels greater than 10 µg per dL 3.
- In the absence of local guidance, healthcare providers should follow the CDC's recommendations for screening and treatment of lead exposure 3.
Treatment and Management
- Chelation therapy is recommended for children with blood lead levels higher than 45 micrograms per dL (2.17 mumol per L) 2.
- However, treatment with succimer, a lead chelator, did not improve scores on tests of cognition, behavior, or neuropsychological function in children with blood lead levels below 45 microg per deciliter 4, 5.
- The most important treatment strategy is identification and termination of major sources of lead exposure 5.