The University of California, Irvine announced on April 6 that dangerous levels of lead remain in residential neighborhoods near a former battery smelter in Southeast Los Angeles, despite extensive cleanup efforts. The findings come from a new study by UC Irvine’s Joe C. Wen School of Population & Public Health.
The study highlights ongoing public health risks and points to failures in the state’s approach to environmental remediation. Researchers say the issue affects low-income, predominantly Latino communities with many young children, who face greater vulnerability to lead exposure.
According to the research team, more than one-third of yards that had been declared ‘clean’ by state officials still exceeded California’s safety threshold for lead contamination. Jill Johnston, UC Irvine associate professor and corresponding author of the study, said: “These neighborhoods are predominantly low-income, largely Latino and home to more young children than the county average, yet more than a third of yards the state declared ‘clean’ still exceed its own safety threshold. That’s a systemic failure in how this cleanup was designed and verified. The community knew something was wrong – and the data proved it.”
The investigation involved collecting over 1,100 soil samples from nearly 400 properties between October 2021 and September 2024. The results showed that contamination spread primarily north and northeast of the site—sometimes beyond official cleanup zones—and also revealed evidence suggesting recontamination may be occurring as contaminated dust moves through these areas.
Lead exposure is especially harmful for children due to risks such as learning disabilities and behavioral challenges; among adults it is linked to cardiovascular disease. In California alone, annual economic costs related to lead exposure are estimated at $8 billion to $11 billion.
Community advocacy played an important role in pushing for expanded testing and stronger oversight based on preliminary findings from this research partnership with East Yard Communities for Environmental Justice. Johnston said: “This is what community-based participatory research can do… But rebuilding trust in communities that have been failed for decades will take sustained commitment.”
Researchers recommend enforcement of cleanup plans while addressing sources of recontamination and involving residents closely in decision-making about neighborhood-scale remediation efforts.
University of California Irvine participates in NCAA Division I athletics according to its official website. The university has earned a Carnegie classification for very high research activity according to its official website and operates within the University of California system according to its official website. UC Irvine focuses on advancing knowledge through research, education, public service with an emphasis on inclusive excellence according to its official website, engages internationally through collaborations according to its official website, and holds accreditation from the Western Association of Schools and Colleges Senior College and University Commission according to its official website.