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US lowers threshold for lead poisoning in young children

AP Medical Writer

NEW YORK (AP) – U.S. health officials have changed their definition of lead poisoning in young children – a move that is expected to more than double the number of children with worrying levels of the toxic metal in their blood.

The stricter standard announced Thursday by the Centers for Disease Control and Prevention means the number of children aged 1 to 5 considered to have high blood lead levels will drop from around 200,000 to around 500,000.

Some experts believe the change was overdue. The CDC last changed the definition nine years ago and has committed to considering an update every four years. But work on a review encountered obstacles under the Trump administration, said Patrick Breysse, who heads the CDC’s National Center for Environmental Health.

Children can be exposed to lead through pieces of old paint, contaminated dust and – in some cities – drinking water that passes through lead pipes. Metal builds up in the body and at very high levels it can damage organs and cause seizures.

But it can also have insidious effects at lower levels, especially in young children. Children can absorb four to five times more lead than adults exposed to the same source, which impairs children’s brain development and leads to attention and behavior problems.

“There is no such thing as a safe level of lead,” said Dr. Marissa Hauptman, a pediatrician at Boston Children’s Hospital who sees children exposed to lead.

When a child is found to have high levels of lead in their blood, public health officials are supposed to try to find the source and take action to clean it up. Hauptman said she hoped the standard change would come with additional funding for this work, but CDC officials said there was no new funding accompanying Thursday’s announcement.

Lead poisoning is assessed using a measurement of micrograms of lead per deciliter of blood. In the late 1970s, the average blood lead level in American children aged 1 to 5 was 15 micrograms per deciliter. The most recently reported measurement, covering the years 2011-2016, was 0.83 micrograms.

This decline in American children has been attributed to laws that have phased out the use of lead in paints and gasoline and other prevention and cleanup efforts. But as overall lead levels declined, scientists have accumulated evidence that even small amounts of lead can affect intellectual development.

In 1991, the standard for children was set at 10 micrograms per deciliter. In 2012, it was reduced to 5 micrograms. The new standard announced Thursday is 3.5 micrograms.

Change has been happening for years. Health officials concluded in the closing days of the Obama administration that the standard should be lowered. But during the Trump administration, he failed to get the necessary approvals from entities such as the White House’s Office of Management and Budget, Breysse said.

“This administration is more favorable,” he said.

Columbia University public health historian David Rosner said the CDC was “vulnerable to political winds.”

“The fact that they are doing it now is an indication that they feel a bit liberated,” said Rosner, who has co-authored books on lead poisoning and other forms of pollution.

Lead exposure can be a problem anywhere, but research shows it’s a bigger problem in poor communities and is concentrated in cities in the Northeast and Midwest with housing older.

Hauptman said the standard change is complicated by the recent recall of a test kit.

Earlier this year, Magellan Diagnostics Inc. recalled some of its blood lead test kits because some of them gave falsely low blood lead levels. This month, the CDC informed doctors that the recall had been extended to most of the kits distributed last year.

“When you’re talking about a level of 3.5, that precision matters,” Hauptman said.

Health officials stressed that other types of blood lead tests remained available. But some have also noted that the standard change comes at a time when they face other challenges.

For example, the Baltimore City Department of Health’s major screening programs were suspended last year as staff and resources were moved to deal with the COVID-19 pandemic. The department plans to resume its lead testing program in January, a spokesperson said in an email.


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