CDC lowers blood lead reference value for kids

The CDC announced that it has lowered the blood lead reference value for children from 5 µg/dL to 3.5 µg/dL.

The change was made in response to a recommendation from the Lead Exposure Prevention and Advisory Committee, which is charged with reviewing and identifying best practices for lead screening and lead poisoning prevention. According to the CDC, the reference value is based on the 97.5th percentile of blood lead level distribution in children aged 1 to 5 years from the National Health and Nutrition Examination Survey.

“Lead exposure at all levels is harmful to children and can be detrimental to their long-term health,” CDC acting Principal Deputy Director Debra Houry, MD, MPH, said in a press release. “I am confident this update will allow us to further safeguard the health of the next generation.”

Although the geometric mean blood lead level in U.S. children aged 1 to 11 years has declined since 1980, the threat of lead exposure still exists, according to Perri Zeitz Ruckart, of the CDC’s National Center for Environmental Health/Agency for Toxic Substances and Disease Registry, and colleagues.

“Black or African American children, those living in low-income households and those who are immigrants or refugees are more likely to live in communities where lead is pervasive,” they wrote in MMWR.

The researchers noted that 2.5% of children aged 1 to 5 years in the U.S. have blood lead levels greater than or equal to 3.5 µg/dL.

Lead exposure in children can cause brain and nervous system damage, slowed growth and development, learning disabilities, hearing and speech problems, lower IQs and a decreased ability to pay attention, according to the CDC.

Ruckart and colleagues encouraged health care professionals to offer nutritional counseling that helps lessen lead absorption to children with blood lead levels between 3.5 and 5 µg/dL. Health care professionals should also try to obtain their environmental history to identify potential sources of lead exposure. The most common sources in the U.S. include lead-based paint and dust, contaminated soil, water from lead pipes and plumbing fixtures, as well as some toys and jewelry, candies from other countries, “traditional home remedies” and occupations and hobbies involving lead-based products, the researchers wrote.

Ruckart and colleagues recommended universal blood lead level testing and urged public health and clinical professionals to focus efforts on neighborhoods and children at higher risk based on the age of housing and sociodemographic factors. They also encouraged jurisdictions to follow the CMS requirement that all Medicaid-enrolled children be tested at ages 12 and 24 months or at 24 to 72 months if they were not previously screened.

The AAP states that pediatricians should “screen all children for risk factors that may result in lead exposures by asking about the age of the home, parental occupations and hobbies, use of ethnic foods and spices, and hand to mouth activity.”

However, the U.S. Preventive Services Task Force has previously stated that there is insufficient evidence to determine the balance and harms of screening for elevated blood lead levels in asymptomatic children aged 5 years and younger. The USPSTF also noted that the American Academy of Family Physicians recommends against routine screening for elevated blood lead levels in asymptomatic children aged 1 to 5 years at average risk.

References

AAP. Lead exposure: Steps to protect your family. https://www.healthychildren.org/English/safety-prevention/all-around/Pages/Lead-Screening-for-Children.aspx. Accessed Oct. 28, 2021.

CDC. Health effects of lead exposure. https://www.cdc.gov/nceh/lead/prevention/health-effects.htm. Accessed Oct. 29, 2021.

CDC. CDC updates blood lead reference value for children. https://www.cdc.gov/media/releases/2021/p1028-blood-lead.html. Published Oct. 28, 2021. Accessed Oct. 28, 2021.

Ruckart PZ, et al. MMWR. Morb Mortal Wkly Rep. 2021;doi:10.15585/mmwr.mm7043a4.

USPSTF. Elevated blood levels in children and pregnant women screening. https://www.uspreventiveservicestaskforce.org/uspstf/recommendation/elevated-blood-lead-levels-in-childhood-and-pregnancy-screening. Published April 16, 2019. Accessed Oct. 28, 2021.