For the 52,000 residents living around the Reid-Hillview Airport in San Jose, there's a public health threat looming over the community. Daily aircraft traffic is contaminating the area with lead, and it's causing a spike in the blood lead levels in children, according to a new study commissioned by Santa Clara County that noted other area airports are also likely contaminating local communities.
The study, released Tuesday, found that children living within 1.5 miles of the Reid-Hillview Airport have elevated levels of lead in their blood, and that the problem gets much worse for those who live closer to or downwind from the airport. County officials say the worrying findings show a spike in blood lead levels as significant as the height of the Flint water crisis in Michigan.
County Supervisor Cindy Chavez said the results are "rock solid" evidence that airport traffic is harming the public, and that exposure to lead is particularly harmful in children. It can lead to lower IQs, decreased success in school, behavioral problems, hypertension and coronary disease.
"What this very thorough study proves is that we literally have a crisis on our hands," Chavez said at a press conference Tuesday. "This is a public health issue, it's an environmental justice issue and it's an equity issue."
The study dove into public health data spanning a decade, and found that children under the age of 18 living close to Reid-Hillview had blood lead levels over 1.8 micrograms per deciliter. In 3.2% of the children surveyed, that number was as high as 3.5 micrograms, and in 1.7% of children it was 4.5 micrograms. Average baseline lead levels in children across the United States are closer to 0.84 micrograms.
Children can suffer substantial and long-lasting health effects from even low levels of lead in the blood, and the U.S. Centers for Disease Control and Prevention (CDC) has concluded that there are no safe blood lead levels in children.
Though the analysis honed in on residents living around Reid-Hillview, the study notes that all airports in Santa Clara County servicing piston engine aircrafts -- which use leaded aviation gasoline -- are likely contaminating other communities as well. Moffett Federal Airfield, Palo Alto Airport, Norman Y. Mineta San Jose International Airport and the San Martin Airport all serve planes that leave behind lead that can be inhaled and ingested by residents below.
The study compiled 2,500 records from these airports, including health records of children, and found similar results.
"Again, we find that child blood lead levels decrease with distance from the nearest airport, are significantly higher among children residing east of the nearest airport, and increase with the volume of piston engine aircraft traffic," according to the study.
But Sammy Zahran, the author of the study, said he would caution against generalizing the results of the study for all airports in the county, and that each airport is different in terms of volume of traffic and proximity for neighborhoods. In some cases -- like at San Martin -- the available public health data was paltry, and only 68 children were sampled over a 10-year period.
"I think it would be important to perform analyses at these other airports," he said.
Chavez also advocated for a broad approach, and said up to 4 million people across the country live within a short distance from airports and could be subject to the same health hazards.
"This issue needs to be resolved both in our community ... but it's also an issue that the FAA (Federal Aviation Administration) and the federal government need to address in order to make it safe for people to breathe the air if they live near an airport."
Reid-Hillview Airport has been the subject of scrutiny in recent years, operating right alongside homes and near several schools in East San Jose. Though automobiles have operated on unleaded gasoline for decades, aircraft taking off and landing at Reid-Hillview are still using leaded aviation fuel, spreading the toxic metal in a concentrated ring around the airport.
In 2018, the Santa Clara County Board of Supervisors voted narrowly 3-2 to stop accepting federal grants to operate Reid-Hillview, opening an opportunity for the county to shut down the airport as soon as 2031. Chavez said the study adds a sense of urgency, and that the significant hazards to children living near the airport could be used to petition the FAA for a faster closure. The board is scheduled to review the study at a meeting on Aug. 17.
Dr. Bruce Lanphear, a pediatric epidemiologist, said the airborne lead settles on the windowsills, tabletops and floors of the homes below, putting young children and toddlers at particularly high risk of ingesting the lead. He said the study on Reid-Hillview is one of the most thorough and conclusive reports he's read over the course of his 25-year career and accounts for all other sources of lead, including lead-based paint that remains in many older households.
"The results all point to the same conclusion -- the Reid-Hillview Airport endangers the lives of people who live around the airport, and especially children," Lanphear said.
Blood samples of children around Reid-Hillview show that residents living within half a mile of the airport are at higher risk than those between 0.5 and 1.5 miles away, with an average 0.2-microgram per deciliter increase for those living in the nearest orbit. That spike alone is roughly half of the estimated increase in blood lead levels examined during the Flint water crisis, Zahran said, but with one key difference: The airport's emissions have been constant for far longer.
"The height of the Flint water crisis, from start to finish, unfolded in less than a year and a half," he said. "By contrast, at Reid-Hillview, the release of lead into the lived community is continuous -- a daily, unabated stream of an undeniable harmful toxin."
Chavez described the airport as an "incongruous" land use with the nearby residential neighborhoods, and said that the brunt of the health impacts harm residents who are least affluent in the community. Almost half of the households have a high school diploma, and more than 75% speak a language other than English at home, she said.