A coalition of community and environmental organizations from across the country filed a lawsuit asking a federal appeals court to review a rule addressing childhood lead exposure, saying the rule illegally allows children, including tens of thousands of Hoosier children, to be exposed to toxic lead.

Lead exposure has been a threat for Hoosiers for more than a century. According to the EPA, industrial areas around the state often leave behind lead pollution that contaminates the soil and surrounding areas long after a facility is closed. The EPA’s rule sought to provide additional protection to people living in residential areas at risk for lead contamination.

“Lead-contaminated dust from chipped and peeling lead-based paint is one of the most common causes of elevated blood lead levels in children,” said former EPA administrator Scott Pruitt, when the 2018 Review of Dust-Lead Hazard Standards was announced. “Strengthening the standards for lead in dust is an important component of the EPA’s strategy to curtail childhood lead exposure.”

According to the Centers for Disease Control and Prevention, lead can be found throughout a child’s environment. Homes built before 1978 can contain lead-based paint. When that paint peels and cracks, it makes lead dust that can poison children.

The 2018 Review of Dust-Lead Hazard Standards significantly lowered the amount of lead allowed in dust on floors, window sills and soil around a home.

The rule lowered the amount of lead allowed on floors from 40 μg/ft 2 to 10 μg/ft 2 and on windowsills from 250 μg/ft 2 to 100 μg/ft 2.

Despite the positive change, community groups say lead allowance in the EPA’s 2018 standards could unnecessarily damage children’s health, because even small amounts of lead can cause irreversible damage in children.

“Current standards result in inspections that fail to identify homes or schools with dangerous levels of lead,” the groups said in a joint statement. “When that happens homeowners and others do not take measures to reduce lead, exposing families and children to breathing in toxic levels of lead. This is illegal and intolerable.”

The CDC says there is no safe level of lead exposure in children. Exposure to lead can damage the brain and nervous system, slow growth and development, cause learning problems, behavioral problems and hearing and speech issues in children.

Earthjustice, the environmental advocacy group representing the groups in court, says 50% of children living in homes that meet the EPA’s threshold could develop blood lead levels where medical intervention is required.

One of the groups involved in the lawsuit says the EPA’s rule will have the greatest effect on low income Americans and minorities.

“The bottom line is that there is no safe level of lead exposure for children, and any standard that falls short of that jeopardizes the health of millions of children across the country,” said Cecil Corbin-Mark, deputy director of WE ACT for Environmental Justice, a New York City-based health advocacy group. “And this is particularly offensive to low-income communities and communities of color, in which residents tend to reside in older structures and often must rely on a landlord’s compliance with these guidelines.”

The Indiana State Department of Health came to a similar conclusion. The ISDH says children at higher risk for lead exposure tend to live in households in which residents are lower-income, belong to racial or ethnic minority groups, are recent immigrants, live in older and poorly maintained properties or have parents or household members who work in industries that deal with lead.

Under the Indiana Administrative Code, a child must have a blood lead level of at least 10 μg/dL to be considered elevated. That allows the state to initiate “public health actions” that vary depending on the child’s blood lead levels, ranging from arranging additional testing to requiring property owners to immediately remediate contaminated property.

According to the CDC’s National Childhood Blood Lead Surveillance Data, every year about 44,000 children in Indiana under 6 years old get tested for lead contamination. On average, about 235 children per year test positive for what the state considers elevated lead blood levels.

In East Chicago, Ind., the remnants of a lead smelting and chemical manufacturing plant have threatened the health of residents living near the USS Lead Superfund site for decades.

Since the 1980s, state and federal agencies have found evidence of lead contamination in residential areas surrounding the site. Children living in those communities showed evidence of elevated blood lead levels, but, after several remediation attempts, residents were told the area was safe from contamination.

Six years later, the EPA found soil near and under the West Calumet Housing Complex was contaminated with lead levels 70 times the U.S. safety standard. The apartment complex was closed, and more than 1,000 residents were forced to find new housing.

The lawsuit could be heard by the U.S. Court of Appeals for the Ninth Circuit later this year.