From the Guidelines
There is no "normal" blood lead level in a 24-month-old child, as no amount of lead in the blood is considered safe, and the Centers for Disease Control and Prevention (CDC) currently uses a reference value of ≥5 μg/dL (≥50 ppb) to identify children with blood lead levels that are higher than most children's levels 1.
Key Points to Consider
- The American Academy of Pediatrics (AAP) recommends that any blood lead level at or above the reference value requires follow-up and intervention, including identifying and removing lead sources from the child's environment 1.
- Lead exposure is particularly concerning in young children because their developing brains and nervous systems are more vulnerable to lead's toxic effects, which can cause irreversible neurodevelopmental damage, learning difficulties, and behavioral problems.
- Lead can enter a child's body through ingestion or inhalation from sources like old paint, contaminated dust, soil, water, or certain consumer products.
- Regular screening for lead exposure is recommended at 12 and 24 months of age, especially for children living in older homes or high-risk areas.
Recommendations for Blood Lead Levels
- For blood lead levels <5 μg/dL (<50 ppb), review laboratory results with the family, repeat the blood lead concentration in 6–12 months if the child is at high risk for lead exposure, and provide anticipatory guidance about common sources of environmental lead exposure 1.
- For blood lead levels ≥5 μg/dL (≥50 ppb), perform steps as described above, retest venous blood lead concentration within 1–3 months to verify that the lead concentration is not rising, and refer the patient to local health authorities if such resources are available 1.
From the Research
Normal Blood Lead Levels in Children
The definition of a normal blood lead level in children has evolved over time due to advancements in research and understanding of the effects of lead exposure.
- Historically, a blood lead level of 10 microg/dL was considered the threshold for public health action 2.
- However, more recent studies have suggested that even lower levels of lead exposure can be harmful, with some arguing for a threshold as low as 2 microg/dL 3.
- The Centers for Disease Control and Prevention (CDC) has established a new reference value of ≥ 5 μg/dL for identifying children with elevated blood lead levels (EBLs) 4.
Blood Lead Levels in 24-Month-Old Children
While there is no specific data provided for 24-month-old children, studies have reported the following blood lead levels in children of similar ages:
- A study in Brazil found a median blood lead level of 1.65 ± 1.45 μg/dL in children aged 1-10 years living near a metallurgical plant 5.
- Another study in Nepal reported a mean blood lead level of 4.39 ± 7.35 μg/dL in children between 8-18 years of age 6.
- It is essential to note that these values are not specific to 24-month-old children, but they do provide some context for blood lead levels in young children.
Key Points
- The CDC's new reference value of ≥ 5 μg/dL is used to identify children with elevated blood lead levels 4.
- Even low levels of lead exposure can be harmful to children's health and development 2, 3.
- Further research is needed to determine the optimal threshold for blood lead levels in children, particularly in specific age groups like 24-month-old children.