Parents have long been told that a home built after 1978, the year lead-based paint was banned for consumer use, is a lead-safe home. A new study out of Rutgers University challenges that assumption. Researchers found that lead-contaminated dirt from yards and sidewalks is being tracked indoors on shoes and clothes, leaving hazardous lead dust on the floors of houses that have no lead paint on the walls at all.
The findings were published in the Journal of Exposure Science and Environmental Epidemiology and are based on soil and dust samples collected by community scientists in East Trenton, New Jersey. That neighborhood was added to the EPA's Superfund National Priorities List in 2025 after federal officials found widespread soil lead from 19th-century pottery plants.
What the study found
Working with the East Trenton Collaborative, researchers from Rutgers' Environmental, Occupational and Health Sciences Institute analyzed 242 bare surface soil samples and collected interior floor, windowsill and window-well dust from 42 homes. They measured lead with X-ray fluorescence analyzers.
The soil results were striking. Eighty-six percent of the samples exceeded the EPA's residential hazard level of 200 parts per million, and nearly 94 percent exceeded the stricter screening level used where multiple sources of lead are present. Indoors, 80 percent of floor dust samples from homes with no interior lead-based paint exceeded safety limits.
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"The research shows no significant difference in interior floor lead levels between homes with lead-based paint and those without, which confirms that outdoor soil tracking is a cause of indoor lead dust," said Sean Stratton, the study's lead author and a recent Rutgers School of Public Health Ph.D. graduate, in a statement released with the paper.
Stratton also flagged how directly children come into contact with the contamination. "This is especially concerning because all samples were collected from bare soil at the surface, which is the most likely to be accessed by children or tracked into homes," he said.
Why the 1978 rule is not a full answer
The federal ban on lead in residential paint took effect in 1978, and many families use the age of their house as a rough test of safety. The Rutgers team says that shortcut can miss a large share of the actual exposure.
"The findings are significant because the thought was if there was lead in the dust, it's coming from the paint on the walls and if a house was built after 1978 there was nothing to worry about, but that's not always true," said Brian Buckley, director of research at the Rutgers Environmental, Occupational and Health Sciences Institute.
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Soil near roadways, older industrial lots and demolition sites can hold lead deposited decades ago from leaded gasoline, exterior paint weathering off older buildings, and past industrial activity. Once it is on shoes and pet paws, it can settle on floors, rugs and low surfaces where small children play.
How common is this problem
Contaminated soil is not just an East Trenton issue. In January 2024, the EPA cut its recommended residential soil screening level for the first time in three decades, from 400 parts per million down to 200 parts per million, and to 100 parts per million at properties with more than one lead source. The agency said the change reflected updated science showing children are harmed at lower doses than previously understood.
An analysis of citizen-collected soil samples across the United States, cited in the peer-reviewed literature, estimated that about one in four U.S. households may have soil lead above the new screening level. That translates to roughly 29 million homes.
What families can actually do
There is no safe level of lead in a child's blood, according to the EPA and the Centers for Disease Control and Prevention. Both agencies recommend a set of low-cost habits that specifically target the soil-to-dust pathway the Rutgers team documented.
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The EPA advises families to wet mop floors and damp wipe windowsills and other hard surfaces about once a week, since dry sweeping can spread lead dust rather than remove it. Adults are told to remove work clothes and shoes before entering the home to avoid tracking in soil from yards, streets or job sites.
Outdoor habits matter as well. The agency recommends guiding children to play on grass or covered areas rather than bare soil, especially near roadways, older buildings and abandoned lots. Washing children's hands with soap and water, particularly after outdoor play and before eating, is one of the simplest ways to interrupt the hand-to-mouth route.
Families who suspect a problem can ask a pediatrician about a blood lead test. The CDC recommends testing at ages 12 and 24 months for children enrolled in Medicaid, and risk-based testing for other children who may have been exposed. Local health departments and state extension services can also point families to certified soil testing.
Lead exposure in young children is linked to lasting damage to brain development, behavior and vital organs. The message from the Rutgers work is not that every home is unsafe, but that the age of the paint on the walls is not the whole story.
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This article is made and published by Jesper Bengtson, who may have used AI in the preparation.