Researchers have found toxic levels of lead in the tap water in Watts, south of Los Angeles. The city’s residents may be at serious risk from the water’s health effects. The researchers believe the problem is due to the neglect of the city’s infrastructure.

According to the study released Wednesday, the toxic metal was found more frequently in samples from homes in public housing projects in the neighborhood, where heavy metal contamination of drinking water has occurred in the past due to problems with the plumbing. According to the U.S. Environmental Protection Agency (EPA), any level of lead in drinking water is considered unsafe.

However, some of the water samples in Watts contained lead levels so high that they required special regulatory action under standards set by the EPA. Those samples contained more than 15 µg/L, or 15 parts per billion, of lead, according to the researchers. That’s the so-called action level set by the EPA, at which infrastructure repairs and public notification of the problem are required.

The study, which calls for state-mandated water testing throughout Watts, was conducted by researchers from universities including UCLA, USC and the University of Michigan and commissioned by the Better Watts Initiative, the environmental law arm of the Watts Labor Community Action Committee, which advocates for “clean air, land and water” in the South LA neighborhood.

“This is a scandal. The health, welfare and civil rights of this community have been neglected for generations by leaders of the City and County of Los Angeles,” Tim Watkins, CEO of the committee, said in a statement. “Clean water is a basic human right… The city must answer for its neglect of Watts.”

In children, according to the Centers for Disease Control and Prevention (CDC), lead exposure can cause brain and nervous system damage, learning, hearing and speech disorders, and slowed growth and development.

In adults, meanwhile, health risks include neurological effects, organ damage, and reproductive problems in both men and women, reports the CDC. High lead levels can be fatal.

According to the study, lead has contributed to many “avoidable health inequities” in Watts, including an average life expectancy that is 14 years shorter than in surrounding areas.

In a statement, one of the study researchers called the situation “a public health and environmental crisis.”

“Many residents of the Watts community drink and bathe in water that is not harmful to their health,” said Danielle Hoague, the study’s lead researcher and a doctoral student at the UCLA Institute of the Environment and Sustainability. She said the EPA should immediately conduct water testing throughout Watts in light of the study’s findings.

The study specifically blames the dangerous lead levels on decades-old problems with the water supply in Watts, where lead-containing water pipes were installed in homes before the Safe Drinking Water Act banned the use of such pipes in the mid-1980s. According to the study, landlords and homeowners generally cannot afford to replace these corroding pipes, as well as faucets and other fixtures.

Watts, which covers three square miles north of Compton, is one of the most polluted neighborhoods in the state of California, according to CalEnviroScreen, the mapping tool of the California Office of Environmental Health Assessment (OSHA).

Nearby areas in the South Los Angeles region, including Commerce, Lynwood and Compton, also report similarly high pollution levels.