Santa Ana lead contamination linked to 20th century vehicle emissions

To examine lead contamination in Santa Ana, and how vehicle emissions have played a role, researchers went back in time. 

It’s a time-consuming effort, one that requires much detangling, but UC Irvine researchers painstakingly dug through archives of historical Santa Ana, putting together a look at its fledgling footprint in the early 1900s. 

Meanwhile, UCI researchers and community volunteers collected soil samples around Santa Ana, which were sent to a lab for detailed testing of lead measurements. 

Placed side-by-side, the two maps — one a historic outline of Santa Ana’s roads, traffic patterns and houses and the other highlighting the current and highest lead contamination levels — were nearly identical. 

UCI researchers concluded, in a pair of recent studies, that historic leaded gasoline is a “predominant contributor to contemporary soil-lead contamination in Santa Ana.”

“The current approach used by public health agencies to prevent lead poisoning, which is primarily focused on lead paint and consumer products, is overlooking leaded gasoline as a major source of environmental lead,” said Juan Manuel Rubio, a historian and UCI Mellon Humanities Faculty Fellow. “Our results also indicate that legacy soil-lead may be present in many other urban environments that received similar flow of traffic to Santa Ana during the 20th century.”

Concerns about lead in Santa Ana are not new. Much has been written about how Santa Ana’s communities, particularly lower-income households, grapple with lead contamination and its impact on children. 

But this newer study sought to answer a different question: Where did all this lead come from in the first place? 

“Lead soil contamination in Santa Ana is quite clearly anthropogenic,” Shahir Masri, an environmental scientist at UCI and an author of the studies, told the Register. 

In layman’s terms, evidence suggests lead contamination is human-related. 

Masri dug deep into the archives, digitizing old images and painting a layout of Santa Ana a century in the past. 

Through the use of historical mapping, researchers found greater concentrations of lead in modern times around the historic downtown of Santa Ana which has “experienced higher traffic volumes over a longer period of time.”

Additionally, maps from the Automobile Club of Southern California in the 1920s and 1930s showed the historical 101 highway (now Interstate 5), the primary route between Los Angeles and San Diego, ran through Santa Ana, according to the study. 

“It’s quite clear where human civilization, where society was settling, where the urban area was at the early part of the 20th century, something about that translated to higher lead in the soil,” said Masri. “We know that paint and vehicle emissions are leading causes of lead soil contamination so the mechanism is there. Showing that is pretty important.”

The map of lead levels around Santa Ana, created by the UCI researchers, showed the highest concentration of lead in the northern and central parts of town. This includes the downtown, Fisher Park, Floral Park, Willard and Flower Park neighborhoods, according to the map. (The historical maps showed the downtown area, particularly First, Fifth, and Main streets, were arteries for the highway.) 

Leaded gas long considered a ‘major public health problem’

Lead in gasoline has existed since the early 1920s, and the EPA began to set reduction standards in 1973. Twenty years later, the Clean Air Act, the country’s comprehensive environmental law, banned the sale of leaded fuel outright for on-road vehicles, according to the EPA. 

The impacts of leaded gasoline have long worried environmentalists. 

“There is no doubt in my mind that lead in the environment is still a major public health problem, and that leaded gasoline is a major contributor to total lead exposure,” Lee Thomas, the EPA administrator during the Reagan administration, said in 1985. 

“The elimination of lead from gas is one of the greatest environmental achievements of all time,” Carol M. Browner, the EPA chief under the Clinton administration, said in 1996. 

It was Algeria that was the last country to use leaded gasoline, phasing it out by mid-2021. 

Lead exposure can lead to damage to the brain or nervous system as well as hearing and speech issues in children, according to the Centers for Disease Control and Prevention. Although difficult to see, the effect can be long-term, the CDC warns.

How is Santa Ana tackling lead contamination?

Patricia Flores, the Orange County Environmental Justice project director who worked on the studies, noted the highest levels of lead were found in Santa Ana’s lower-income neighborhoods, replete with immigrants and families.

“These are already the most marginalized communities in Orange County,” Flores said, calling the contamination an “environmental crisis” that especially impacts younger generations. 

Although the studies only looked at Santa Ana, Masri said comparable areas in Southern California could experience similar contamination issues near older roadways. 

Minh Thai, the executive director for the Planning and Building Agency of Santa Ana, agreed: “This could likely be something that affects many communities throughout the state of California — especially ones that are next to the major corridors.”

When the Santa Ana City Council approved the city budget for the 2022-2023 fiscal year, it included funding for a new “Environmental Justice Section” in the Planning and Building Agency. 

Thai wants the position to be filled “right away.” In addition to the new role, other professional technical positions and administrative support from the agency will be allocated to the environmental section. 

“We’re one of the first cities, if not the only city in the state of California, to really take the environmental justice issue seriously because it is a serious matter for our residents,” Thai said in an interview. “We understand that these contamination issues don’t just get addressed overnight.”

Thai said it’s a multi-pronged approach to addressing lead issues in the city, which includes engaging the community, identifying problem areas, educating on the health effects and prevention and abating lead contamination. 

These are all approaches the new environmental justice leader, once chosen, will consider, Thai said. 

But addressing, specifically, the impact of vehicle emissions on Santa Ana’s soil may be a “longer-term issue.”

“Our resources are limited, and we’re evaluating how best to use our resources to help our community,” Thai said. “Right now, the first step is addressing the real impacts being felt by our residents, and then the longer-term issue is to look at how we can start to address some of the source polluters that have created these problems.”

One possible option for down the road — albeit, a costly and time-consuming one that, while he floated it, is not at the top of Thai’s to-do list — is to pursue remediation or litigation with current or past polluters. Thai pointed to public agencies that build and support roads, car manufacturers and petroleum producers, for example. 

“There are a variety of responsible parties. The question is then who, if not all, can be held accountable,” Thai said. “That’s really a very expensive and complicated process so by no means I’m advocating we take that route.”

The two UCI studies can be found in the Environmental Research and Toxics journals. 

Source: Orange County Register