
Another Step Toward Environmental Justice
¡Plo-NO! Santa Ana moves forward with I-CLEAN study
When Maria Isabel Tinajero Salazar came to the United States from Mexico 15 years ago, she – like most people in a new country – didn’t understand how to access resources and reliable information. “Now I feel like it’s my duty to help others who may be in that position,” she says. Tinajero Salazar is a promotora – a Spanish-speaking community health worker – and part of a team of community activists, residents and UC Irvine researchers known as the ¡Plo-NO! Santa Ana coalition. (“Plo-NO” is a play on the Spanish word plomo, which means lead.)
The activists – who include investigators Alana LeBrón, UC Irvine associate professor of health, society and behavior as well as Chicano/Latino studies, and Jun Wu, professor of environmental and occupational health, along with members of Orange County Environmental Justice and Madison Park Neighborhood Association’s Getting Residents Engaged in Empowering Neighborhoods effort – are determined to shed light on lead contamination, a neurotoxic danger lurking in the soil of Santa Ana. Working on the issue since about 2018, ¡Plo-NO! Santa Ana has already proved that lead is a serious problem in the city. But the next phase of their work, they say, is the most important.
Researchers have long understood that Santa Ana activists prioritized the health impacts of lead and had one looming concern: What about our children?
“We’ve known for a while that this is a big question,” LeBrón says. “And the reality is that the data currently available are not very good at answering that question.”

Enter the Inequities in Childhood Life-Course Lead Exposure and Academic and Neurobehavioral Outcomes (I-CLEAN) study, which began last summer. Salazar and a team of about a dozen promotoras aim to enroll 700 Santa Ana children between the ages of 7 and 10.
A five-year study funded by a $2.7 million grant from the National Institute of Environmental Health Sciences, I-CLEAN will explore the connection between lead exposure and children’s school performance and behavior. Lead is a neurotoxic metal that can negatively affect the developing brain. Children are particularly susceptible to exposure since they can absorb lead more readily than can adults. There is no safe level for lead. Research suggests that even low-level exposure during pregnancy and early childhood could impact a child’s development.
“This project is very much rooted in action. Public health is supposed to be the people’s health.”
– Alana LeBrón, UC Irvine associate professor of health, society and behavior and Chicano/Latino studies
The promotoras will use their lived experience as community members and knowledge of lead and I-CLEAN research processes to partner with academic researchers to spread the word about I-CLEAN, enroll families in the study, and accompany residents in learning about and responding to concerns about lead, according to Eva Sandoval, health equity coordinator for the Madison Park Neighborhood Association’s Getting Residents Engaged in Empowering Neighborhoods effort and a UC Irvine master’s student in public health: “We have a real sense that the community wants to be a part of this research and find answers. We’re ready to enroll.”

Families will be asked to complete simple questionnaires, and researchers will collect blood and a naturally shed baby tooth from the children. Families will also consent to giving them access to school records. Each participant can be compensated up to $170.
This latest phase of the lead project has the potential to inform researchers about both short-term exposures, which is seen in blood, and the story the child’s body is telling. Wu says that teeth, like the rings of a tree, offer clues to the child’s neurotoxin exposure. “Historical evidence will exist in those teeth about lead exposure at different times in that child’s life, including clear back to in utero,” she says.
I-CLEAN research coordinator Julia Mangione says that the group has so far taken part in seven community events to recruit participants and that community investment in the study is high. “This is a really beautiful example of academic partnership and research driven by community concerns,” she says. “But it will still take plenty of time to get enough people enrolled.”
The team estimates that enrollment will take two years. Researchers say they expect to have the first batch of preliminary results as early as spring 2025. I-CLEAN should offer insights into many questions, but answers have been a long time coming for the community.
Long History of Lead Concerns

“The lead issue in Santa Ana has huge historical significance,” explains Patricia Jovel “P.J.” Flores, executive director of Orange County Environmental Justice and one of the study’s principal investigators, along with LeBrón and Wu. “This was something brought to the attention of the public by the Black Panther Party in the 1970s.”
Flores, who grew up on Townsend Street in Santa Ana, notes that Black Panther members voiced concern about many newly desegregated areas in the U.S. “They were realizing that a lot of the neighborhoods that were opened up for housing to people of color had really high incidences of lead contamination,” she says, but officials never took the concerns seriously, and the issue went by the wayside as the Black Panther movement eventually dissolved. But residents didn’t forget.
In 2017, investigative environmental journalist Yvette Cabrera picked up the issue. She walked the streets of the city with a portable X-ray fluorescence device, documenting high concentrations of lead in parks, open spaces and backyards. But officials also largely dismissed Cabrera’s findings, researchers say.
In fact, LeBrón says, officials deflected blame: “I’m told folks shared their concerns about [Cabrera’s] findings with the city council and also with the health department.” Although lead testing with an XRF device is a respected form of analysis, residents were told that Cabrera’s research methods weren’t strong enough and that instead of the city’s dirt, they should be concerned about lead levels in Mexican candy and glazed pottery.
LeBrón calls deflection – trying to get individuals to believe that something they’re doing is causing the problem – an unfortunate but common strategy. Fed up with nonaction, residents and activists enlisted the assistance of UC Irvine. “We were able to work together to create a comprehensive study that could withstand scrutiny,” says LeBrón of the first phase of their research.

By 2018, trained community activists, including young people from Jovenes Cultivando Cambios (Youth Cultivating Changes), had collected more than 1,500 soil samples from 500 locations around Santa Ana. UC Irvine researchers then analyzed the samples. The findings were astounding. The California Office of Environmental Health Hazard Assessment considers anything above 80 parts per million of lead in the soil of a residential area hazardous to health. About half the soil samples collected exceeded the California safety recommendation.
“There were samples where we even observed concentrations over 1,000 or 2,000 parts per million,” Wu says. The findings were published in the journal Science of the Total Environment in 2020.
The research team – which included Shahir Masri, an associate specialist in air pollution exposure assessment and epidemiology in UC Irvine’s Program in Public Health – also developed a map of Santa Ana with a vulnerability index score for each census tract. All had elevated lead levels, and 11 tracts were characterized as high-risk, according to the cumulative risk index. The areas most affected were low-income and predominantly Latino neighborhoods. These findings were published in Environmental Science: Processes & Impacts in 2021.
Then the researchers dove even deeper. One particularly labor-intensive but fruitful approach involved tracking down historical photos to estimate roadway use. Partnering with historian Juan Manuel Rubio, then a Mellon Humanities Faculty Fellow in UC Irvine’s School of Humanities (now at UC Santa Barbara), the team provided evidence that leaded gasoline used throughout the 1970s and ’80s in historically high-traffic areas was the most likely primary source of soil lead contamination. Leaded gasoline hasn’t been used in automobiles in decades in the U.S., but since lead doesn’t biodegrade, it can still wreak havoc. In 2022, these findings were published in the academic journal Environmental Research.

That same year, a study led by Masri used isotope analysis to find the signature of lead sources – confirming leaded gasoline as the main culprit. The results were published in the journal Toxics.
While many people associate lead exposure with lead-based paint, Wu says, lead from gasoline is extremely problematic. “The lead that was historically used in gasoline is particularly bad because it creates a distributed problem,” she says, explaining that exhaust from leaded gasoline became airborne and dispersed – finding a home in soil and dust. “That means it’s not just on the road; it’s everywhere in these older communities where you have had a lot of traffic.”
With published university research in the activists’ corner, Santa Ana city officials finally started listening, says Maya Cheav, land and health director for Orange County Environmental Justice. “Once we had UCI’s backing, the city believed there was more credibility,” she says, “which is a bit frustrating since residents had been bringing this up for so many years.” Now the city is working with OCEJ and offering lead testing and abatement services for locals.
Toward Health and Healing

The long goal of all the work is to find ways to improve the health and lives of Santa Ana residents. “This project is very much rooted in action,” LeBrón says. “Public health is supposed to be the people’s health.” Ultimately, the team will create a public health equity action plan to raise awareness of the health and academic implications of lead exposure and advise the community and officials on effective mitigation strategies for residents and the land.
Already, groups are working on novel bioremediation efforts involving native plants and fungi that are thought to absorb lead. But it’s the deep and pervasive generational impacts on lives that OCEJ’s Flores says she’s witnessed that she hopes to understand more. In the early 2000s, for example, gang violence was problematic in Santa Ana. Officials enacted what Flores describes as martial law. Residents could not be out after 10 p.m. “If you were caught, you were fined and put on a database as a gang member,” she says, noting that her younger brother was added to that database. Residents have expressed concerns that, historically, too many youths who got involved in gangs had been pushed out of school through suspensions and expulsions. “A lot of those kids had ADHD, other developmental disorders and behavioral health issues. All those conditions are possible effects of lead contamination,” Flores says.
Researchers caution that the I-CLEAN study will not provide evidence that lead exposure alone caused any specific problem, but it will certainly illuminate some issues. They also warn that Santa Ana is probably not the only city that should be concerned. It may be special because of its civic engagement and activism, but researchers say the area’s lead exposure is likely not unique. Airborne dust from leaded gasoline, industry and lead paint accumulated in many places throughout the 20th century.
Says Wu: “There could be a lot of older cities in the U.S. that may share some of the same lead exposure story as Santa Ana.”
Meet the Promotoras

Community groups like Orange County Environmental Justice and the Madison Park Neighborhood Association’s Getting Residents Engaged in Empowering Neighborhoods effort have been driving forces behind the investigation into soil lead contamination in Santa Ana. For the I-CLEAN study, these groups help organize promotoras – Spanish-speaking community members with connections to families, churches and schools – who hand out flyers and attend community events to enroll families and shepherd them through the research process. UC Irvine public health researchers connect regularly with the promotoras to ensure that they guide and collaborate on implementing the study protocols. We spoke with six promotoras for some insight into their crucial role in the research and why they take part. (Eva Sandoval, UC Irvine master’s student in public health, served as translator.)
“My family has long lived in Santa Ana. We do everything here – go to school, church, the supermarket – and we socialize with one another in Santa Ana. What we know now is that lead is in many places, and it must be addressed. Anything I can do to help other people understand this, I will. I’m a community health worker because I want to help Santa Ana become a better place to live.” – Maria de los Angeles Diaz
“A lot of people in my community are cautious about scientific studies. But because I’ve taken the training from UCI researchers, I can now help. I now understand how the studies have many regulations. I’m happy to learn about these regulations and safeguards, and I can really set the record straight for anyone who may be concerned.” – Teresa Campos
“My family and all the kids in Santa Ana motivate me to help with community health. Finally, we know that eating candy from Mexico is not the only reason for lead exposure. The more I can help get the real truth about lead known, the better I feel.” – Yezenia Teresa Cortez
“The researchers have taken a lot of time with promotoras to explain the study and the findings so far. They’ve also listened to our feedback about the work that we’ll do and taken it seriously. There are always a lot of rumors and misinformation with health and science issues. I love it that I can now be a part of spreading accurate information about such an important topic in my community.” – Yohana Rojas
“Too many people don’t consider where they live, or they don’t take environmental contaminations seriously. I like that I have the opportunity to change that. The more people know, the more they’ll be able to take action for themselves and their families.” – Catalina Iniestra
“As a promotora, I want to teach others about lead and share the resources provided. Not everybody knows this information is available.” – Maria Isabel Tinajero Salazar