The US Environmental Protection Agency (EPA) on June 17 proposed tightening its standard for how much lead dust can be left on floors after contractors remove lead paint from homes and childcare centers. While the proposed standard is a significant improvement over the old one, it is twice as high as the level that health experts have called for.
Exposure to lead is considered unsafe at any level. Lead causes irreversible neurological damage to children, leading to attention deficit disorders and loss of IQ. Children are most likely to get poisoned by nibbling on chips of old leaded paint, which tastes sweet, and ingesting minute lead-paint particles in floor dust. Low-income and minority children are disproportionately affected.
While average blood lead levels of children have plummeted in the US since the 1970s, when regulators began to limit the amount of lead in house paint, chronic low-level poisoning continues. At least half a million children ages 1–5 years have blood lead concentrations above the level at which the US Center for Disease Control (CDC) recommends that parents and others take action to reduce a child’s exposure. About 24 million homes still have lead paint.
When contractors remove lead paint from homes, they test the success of their job by marking out a square foot (0.09 m2) of floor, scooping up lead dust with a special wipe, and sending the wipe off to a lab for analysis. The EPA’s new rules will get homes cleaner after lead abatement and reduce lead poisoning by allowing 10 μg/ft2 (about 110 µg/m2) of lead on floors after cleanup, down from the 2001 standard of 40 μg/ft2 (430 µg/m2).
The action fixes a problem that EPA created last year in response to a court order resolving a 2009 lawsuit. The agency strengthened the hazard standard that may trigger abatement by dropping it from 40 µg/ft2 down to 10 µg/ft2. At that time, the EPA failed to drop the post-cleanup standard, creating a situation where floors with more than 10 µg/ft2 of lead dust would trigger abatement, but a post-cleanup value of more than 10 µg/ft2 but less than 40 µg/ft2 would be deemed acceptable. Contractors complained that the mismatch created ethical and liability issues for them. The new rule realigns the two standards—but is still under fire for not going far enough to protect health.
“EPA’s new floor dust standards are the same as the ones that citizens petitioned for in 2009 and are now outdated,” says Bruce Lanphear, a public health doctor at Simon Fraser University. In 2009, the CDC’s action level for children was 10 µg of lead per deciliter of blood. In 2012, the CDC lowered the level to 5 µg/dL, and research since then supports lowering the dust standard to 5 µg/ft2 or less, he says.
“EPA’s own modeling shows that a child in a house that meets the new standard will have a 9.8% chance of posting a blood lead level over 5 ug/dL and consequently up to a 32% chance of losing two or more IQ points,” says Jonathan Smith, an attorney with the law firm Earthjustice. Earthjustice filed a lawsuit in August 2019 on behalf of environmental groups calling for strengthening the 2019 dust-hazard standard that triggers abatement. The American Academy of Pediatrics and several public health organizations support the lawsuit and have called for a lead-dust standard less than 5 µg/ft2.
The EPA responds that the new standards were based on its evaluation of the best available science. The agency adds that the new standards were also based on consideration of achievability and whether lower dust-lead loadings can be reliably detected by laboratories.
Testing labs must show that the lowest level they can quantify is equal to or less than one-half of the regulatory limit, EPA Assistant Administrator Alexandra Dapolito Dunn says. In the 2019 final rule, EPA said that it was uncertain that laboratories could reliably test for lead loadings as low as 5 µg/ft2.
However, Simon Fraser University’s Lanphear says, “We published a study that demonstrated you can get floor lead dust levels down below 5 µg/ft2 in 100% of cases” (JAMA Pediatr. 2018, DOI:10.1001/jamapediatrics.2018.2382). As part of that study, contractors abated lead in 170 homes and used a testing lab that could measure dust levels down to 1–2 µg/ft2. Additionally, the general manager of one of the nation’s largest lead-testing laboratories confirmed, in a declaration in support of Earthjustice’s lawsuit, that the lab can meet the limits for a 5 µg/ft2 standard.
“It’s also a simple solution to just double the area of floor sampled,” says Tom Neltner, chemicals policy director for Environmental Defense Fund. Neltner has written a brief supporting the Earthjustice lawsuit for the Lead and Environmental Hazards Association, a nonprofit association for people who do testing, training of contractors, and removal of lead paint.
Lanphear worries that the new standards could provide parents with a false sense of security. “EPA is using old science that doesn’t protect kids today,” he says.