A new study from Indiana University has revealed alarming levels of lead contamination across American households.
Led by biochemist Gabriel Filippelli, the research found that 25% of U.S. yards contain soil lead concentrations that surpass the federal safety threshold recently lowered by the Environmental Protection Agency (EPA) to 200 parts per million (ppm).
This adjustment, down from the previous limit of 400 ppm, reflects increased concerns over lead’s potential harm, especially to children. Some states, including California, have imposed even stricter standards, setting their safety levels as low as 80 ppm.
Filippelli expressed his surprise at the widespread contamination, noting that even the more stringent guideline of 100 ppm for households with multiple lead sources was frequently exceeded. This could potentially affect approximately 29 million U.S. households.
Lead, a heavy metal once commonly used in products like gasoline, paint, and plumbing, accumulates in the body and can lead to severe neurological damage, especially in young children.
The study, which analyzed soil samples from nearly 16,000 residences across the contiguous United States, was published on June 18 in the journal GeoHealth. It revealed that around 25% of sampled yards surpassed the new 200 ppm limit, compared to about 12% under the old 400 ppm guideline.
The cost of addressing this widespread contamination is daunting.
Traditional remediation methods, such as digging up and removing the contaminated soil, could cost between $290 billion and $1.2 trillion. These methods, while effective, are costly and can take years, often only initiated after a property has been listed for national priority remediation.
An alternative, more cost-effective method suggested by the study is “capping,” where contaminated soil is covered with about a foot of clean soil or mulch. This method, which can be completed over a weekend, offers a quick and temporary reduction in exposure risks.
Despite the challenges, Filippelli remains optimistic about tackling the lead contamination issue.
“Lead is the most easily solvable problem that we have,” he stated. “We know where it is, and we know how to avoid it. It’s just a matter of taking action.”