LOS ANGELES (Reuters) - With its century-old Spanish-style homes tucked behind immaculately trimmed hedges, San Marino, California, is among the most coveted spots to live in the Los Angeles area.

Three-year old Kendra Nicole Rojas, plays with pet bunnies at her uncle's home where she and her mother Karla Rojas, 26, (R) used to live but moved out after lead paint was found in the home in the Historic South Central neighborhood of Los Angeles, California, United States April 5, 2017. REUTERS/Danny Moloshok

Its public schools rank top in the state, attracting families affiliated with CalTech, the elite university blocks away. The city’s zoning rules promote a healthy lifestyle, barring fast food chains.

Home values in L.A. County census tract 4641, in the heart of San Marino and 20 minutes from downtown Los Angeles, can rival those in Beverly Hills. The current average listing price: $2.9 million.

But the area has another, unsettling distinction, unknown to residents and city leaders until now: More than 17 percent of small children tested here have shown elevated levels of lead in their blood, according to previously undisclosed L.A. County health data.

That far exceeds the 5 percent rate of children who tested high for lead in Flint, Michigan, during the peak of that city’s water contamination crisis.

The local blood test data, obtained through a records request from the Los Angeles County Department of Public Health, shows two neighboring San Marino census tracts are among the hotspots for childhood lead exposure in the L.A. area.

San Marino is hardly alone. Across sprawling L.A. County, more than 15,000 children under age 6 tested high for lead between 2011 and 2015. In all, Reuters identified 323 neighborhood areas where the rate of elevated tests was at least as high as in Flint. In 26 of them – including the two in San Marino, and some in economically stressed areas – the rate was at least twice Flint’s.

The data stunned San Marino Mayor Richard Sun, who said he wasn’t aware of any poisoning cases in the community.

“This is a very serious matter, and as the mayor, I really want to further explore it,” Sun said upon reviewing the numbers presented by Reuters. During an interview at City Hall, he directed city officials to investigate potential sources of exposure.

THOUSANDS OF U.S. LEAD HOTSPOTS

The L.A.-area findings are part of an ongoing Reuters examination of hidden lead hazards nationwide. Since last year, the news agency has identified more than 3,300 U.S. neighborhood areas with documented childhood lead poisoning rates double those found in Flint. Studies based on previously available data, surveying broad child populations across entire states or counties, usually couldn’t pinpoint these communities.

Despite decades of U.S. progress in curbing lead poisoning, millions of children remain at risk. Flint’s disaster is just one example of a preventable public health crisis that continues in hotspots coast to coast, Reuters has found.

The U.S. Centers for Disease Control and Prevention’s threshold for elevated lead is 5 micrograms per deciliter of blood. Children who test at or above that threshold warrant a public health response, the agency says. Even a slight elevation can reduce IQ and stunt childhood development. There’s no safe level of lead in children’s bodies.

In San Marino, old lead-based paint is likely the main source of exposure, county health officials said, but they added that imported food, medicine or pottery from China could also be a factor. About 80 percent of San Marino homes were built before 1960, and the community has a large Asian population, U.S. Census data show.

Exposure from old paint, drinking water and soil are widely researched. Other risks – including some candies, ceramics, spices or remedies containing lead from China, Mexico, India and other countries – are less known.

The L.A. blood data covers nearly 1,550 census tracts, or county subdivisions, each with an average population around 4,000. It shows the number of small children tested in each tract, and how many tested high.

In California, the exposure risks children face can vary wildly by neighborhood. Many L.A. areas have little or no documented lead poisoning. Countywide, 2 percent of children tested high. But in hundreds of areas, the rate is far higher. Reuters crunched the data, and neighborhood-level results can be explored on an interactive map.

In the trouble areas, old housing is commonplace. Nearly half of L.A. County’s homes were built before 1960. Lead was banned from household paint in 1978, but old paint can peel, chip, or pulverize into toxic dust.

Children are often exposed in decrepit housing. But in some U.S. areas, nearly a third of lead poisoning cases can be linked to home renovation projects, said Mary Jean Brown, a public health specialist at Harvard University and former director of the CDC’s lead prevention program.

San Marino residents take pride in preserving their historic homes. Among the measures Mayor Sun wants to consider: An ordinance to ensure safe practices any time home repairs or renovations could disturb lead paint.

Poverty is another predictor of lead poisoning, and many of L.A.’s danger zones are concentrated in low-income or gentrifying areas near downtown and on the city’s densely populated South Side.

In one low-income area of South L.A., Reuters met with the family of Kendra Nicole Rojas, a three-year-old recently diagnosed with lead poisoning, only to find that 63 other small children living within a six block radius have also tested high.

“A lot of people don’t even think of the West Coast as a place where kids get poisoned,” said Linda Kite, executive director at L.A.-based Healthy Homes Collaborative. “The biggest problem we have is medical apathy. Many doctors don’t test children for lead.”

The findings highlight a need for greater medical surveillance, abatement and awareness in the health-conscious county of 10 million, public health specialists said.

The county and city of Los Angeles have dedicated lead prevention programs that work with at-risk families. When a child’s blood levels persist above 10 micrograms per deciliter – double the CDC threshold – the family receives a home inspection, nurse visits and follow-up.

The effects of lead poisoning are irreversible, and the programs’ broader goal is to prevent any exposure. But success hinges on many actors, and assistance from agencies such as the CDC, the department of Housing and Urban Development and the Environmental Protection Agency. Like other regions, L.A. faces a looming hurdle in attacking hazards: President Donald Trump’s federal budget proposals would sharply cut funds for many lead-related programs.

“We’re aware of lots of areas where homes or soil contain significant levels of lead, and those can represent an urgent need to act,” said Maurice Pantoja, chief environmental health specialist for the county program. “Any fewer resources toward poisoning prevention would be a tragedy.”

A POISONED HOME

Just a few miles west of San Marino, in South Pasadena, one boy’s poisoning serves as a cautionary tale.

In an old, pastel-colored home on Hope Street, an infant named Connor was exposed to lead paint and dust in 2012.

The property is owned by California’s Department of Transportation, Caltrans, which had plans to expand a freeway in the area. Its floors were coated in chipping lead paint. During a bathroom repair, a crew showed up in “hazmat suits,” said tenant Cynthia Wright, Connor’s grandmother.

But as the crew worked, stripping toxic paint from walls and fixtures and unleashing plumes of dust, they told the family there was no need to leave the home, Wright said.

That was an unfortunate lapse, the state agency acknowledged. “There were errors in handling communications regarding this property and Caltrans has revised its business practices,” spokeswoman Lauren Wonder said, leading to “greater vigilance.”

Slideshow ( 10 images )

Connor continued crawling around the floors. At age one, he began missing developmental milestones. Suddenly, he lost the ability to use the few words he could say.

When his mother, Heather Nolan, had him tested for lead, the result was almost five-fold the CDC threshold. Lead levels often peak among children ages one to two, when they are increasingly mobile and have hand-to-mouth behaviors.

Now six, Connor needs speech and occupational therapy up to five times a week. He hasn’t been able to integrate in a mainstream classroom.

“It’s not an easy road,” his grandmother said. “I would tell anyone in an old home, you really need to be aware of the risks.”

In 2015, the family settled a landmark lawsuit against Caltrans for $10 million. Wright still lives in the home, which has been remediated.

POOR PROSPECTS

Amid an affordable housing crisis in Los Angeles, many renters don’t confront landlords to fix lead paint hazards, fearing eviction if they raise the alarm, said Kite, the healthy homes advocate. That helps explain why so many children in south and central L.A. test high.

Karla Rojas, 26, was living with her extended family on 30th Street in a low-income area of South L.A. last year when her toddler, Kendra, started getting chronic bouts of illness.

Mother and daughter slept on the floor, near a bookshelf where an inspector later found flaking lead paint. Tested at the local St. John’s Well Child & Family Center, Kendra’s result came back at several times the CDC threshold.

Once county officials got involved, the landlord repainted the shelf and other areas where lead was found. Still, terrified her daughter’s exposure would continue, Rojas moved out.

“When you read about what lead can do, it makes me fear for her future,” said Rojas, watching three-year-old Kendra play with two new pet rabbits.

Exposure is common in the area, said Jeff Sanchez, a consultant at public health research firm Impact Assessment, which works with L.A.’s prevention program. Around the neighborhood, code inspectors have cited at least 35 percent of residential properties for chipping or peeling paint violations over a four-year period.

Paint isn’t the only peril. A mile and a half east, in Vernon, the now shuttered Exide Technologies battery-recycling plant spewed noxious emissions for decades, polluting soil in thousands of properties with lead residue. A planned $175 million cleanup will rely in part on children’s blood tests to determine which properties should be sanitized first. Past testing has shown that children living close to the plant are at heightened risk.

Yet California, like Michigan, doesn’t require lead screening for all children, leaving many untested.

Prompted in part by Reuters’ previous coverage, California cities and lawmakers are pushing new initiatives to protect children.

Bill Quirk, chair of the state legislature’s Committee on Environmental Safety and Toxic Materials, recently introduced a bill to require screening for all small children.

“I strongly support blood lead testing,” said U.S. Congresswoman Lucille Roybal-Allard, who represents part of L.A. County. “It’s important that residents have information about the threats they may face in their communities.”

‘DON’T WORRY, HE’S NOT AT RISK’

California’s current policy is to test children with known risk factors, including those enrolled in government assistance programs for the poor like Medicaid. The protocol, applied unevenly by healthcare providers, can miss poisoned kids.

In 2013, when apparel designer Amanda Gries and her husband, a Hollywood film editor, rented a home in L.A.’s West Adams neighborhood, she was pregnant with son Wyatt, now 3. The century-old mansion was in a rapidly gentrifying area south of downtown, near landmarks such as the Staples Center and the University of Southern California.

Gries, concerned about peeling paint and dust in the home, urged a pediatrician to screen Wyatt before his first birthday.

“The doctor didn’t want to test,” Gries said. “The message was, ‘Don’t worry, he’s not at risk.’ It was like he didn’t fit the profile.”

Gries insisted, and her fears were confirmed when Wyatt tested at nearly double the CDC’s elevated threshold. An inspection found lead in dust on the floor of Wyatt’s bedroom at 30 times the federal hazard level.

The family moved out quickly and searched citywide before settling into a home on L.A.’s west side, chosen because no lead was detected inside. Wyatt is bright and energetic, Gries said, but has impulsive behaviors. He needs occupational therapy for sensory issues, at nearly $200 per session.

Keeping Wyatt away from lead hazards and feeding him a special diet are part of the Gries’ daily routine. Poor nutrition can worsen lead poisoning, allowing children’s bodies to absorb more of the heavy metal.

“All we can do is hope he’s okay,” said Gries.

(Additional reporting by M.B. Pell)