MONDAY, Sept. 27, 2021 (HealthDay News) -- More than 50% of American children have detectable blood lead levels, a new study reveals. And young children who live in places with lots of pre-1950s housing and low incomes have the greatest risk.
"Public health authorities have worked commendably to reduce lead exposure for decades, and yet, substantial risk remains," said study co-author Dr. Harvey Kaufman, head of health trends research for Quest Diagnostics. "Our study is a cautionary tale of the enormous challenge of remediating environments following contamination with toxins dangerous to human health."
For the study, researchers from Quest Diagnostics and Boston Children's Hospital analyzed laboratory blood tests of nearly 1.2 million children under 6 years of age in the United States. Seventy-one percent were under age 3.
Nearly 51% had detectable levels of lead in their blood, the analysis found. About 2% had levels at or above 5.0 µg/dL, the level at which the U.S. Centers for Disease Control and Prevention recommends public health actions. That percentage was down more than 36% since a previous study, which was based on data for 2009 to 2015.
There is no safe level of lead in children, according to the CDC. It's found in paint in older homes, water pipes, areas with heavy industry and in some consumer products.
"While exposure to the highest levels of lead has declined in recent years, most American children are exposed to lead, a substance that is not safe for children at any level," Kaufman said in a Quest Diagnostics news release. "Moreover, our analysis finds that kids in areas with the highest rates of poverty are also the most at risk, highlighting the critical role of social disparities in health."
Here are the key findings:
Six in 10 children living in areas with the most poverty had detectable levels of lead in their blood, compared with 39% of kids in the least impoverished areas.
Children in high poverty areas were nearly three times more likely to have elevated blood lead levels than kids from areas with the lowest levels of poverty (3% versus 1%).
57% of kids from neighborhoods with the most housing built before 1950 had detectable levels of lead compared with 43% of those from areas with the least pre-1950 housing. Their risk of elevated blood levels also was nearly four times higher (4% versus 1%).
In all, 58% of children from predominately Black neighborhoods had detectable lead levels in their blood, compared with 49% of kids in white neighborhoods.
About 3% of kids from Black neighborhoods, 2% of those from white neighborhoods, and 1% of those from Hispanic neighborhoods had elevated blood lead levels.
Nebraska had the highest percentage of kids with detectable blood levels of lead (83%), followed by Missouri (82%), Michigan (78%), Iowa (76%) and Utah (73%).
Six states had elevated blood levels more than double the 2% nationwide rate — Nebraska (6%), Ohio (5%), Pennsylvania (5%), Missouri (5%), Michigan (5%) and Wisconsin (4%).
Any detectable lead level is abnormal and potentially harmful, particularly in young children, the researchers pointed out. A neurotoxin, lead has been associated with brain and nervous system damage, as well as learning, behavior, speech and hearing problems.
"Given the lack of a threshold for the deleterious effects of lead in children and largely permanent effects of poisoning, prevention is extremely important," said co-author Dr. Jeffrey Gudin, senior medical advisor at Quest Diagnostics. "This means limiting exposure and testing" young children's blood for lead "and having them retested periodically if results indicate a potentially unsafe level."
Gudin pointed out that lead exposure isn't always apparent, which is why testing is critical.
Dr. Philip Landrigan of Boston College and David Bellinger of Harvard Medical School co-authored an editorial that accompanied the study.
"The findings from this study underscore the urgent need to eliminate all sources of lead exposure from U.S. children's environments," they wrote.
The report was published online Sept. 27 in JAMA Pediatrics.
For more about children and lead, visit the U.S. Centers for Disease Control and Prevention.
SOURCE: Quest Diagnostics, news release, Sept. 27, 2021