In November 2024, San Diego Mayor Todd Gloria stood on the runway at Montgomery-Gibbs Executive Airport to mark the rollout of unleaded aviation fuel at one of the nation's busiest general aviation facilities.

"Here in San Diego, we aim to go beyond federal rules. We want to lead the way, especially to safeguard public health and safety," he noted. "Today marks a key achievement."

Two years later, Crownair Aviation, which worked with the city to offer the transition fuel known as UL94, has sold just over two dozen gallons. In the same span, more than 1 million gallons of leaded fuel moved through the airport.

Last year, the three-runway site in Kearny Mesa sold more leaded fuel than in any prior year over the past decade. Federal records show it as the top lead-polluting general aviation airport in the country.

Lead, a toxic element banned from car fuels since the 1970s, sees no use in commercial aircraft. It can cause lasting harm to the brain and nervous system, with children facing the greatest risks. No exposure level is considered safe, and even brief contact may slow growth, impair hearing and speech, reduce focus, and lower IQ scores.

"Science shows that lead exposure can trigger lasting health impacts in children," stated Michael S. Regan, then head of the U.S. Environmental Protection Agency, three years ago. He identified aircraft using leaded fuel as the main source of airborne lead, noting that such fuel may account for 70 percent of emissions.

The Federal Aviation Administration intends to end leaded fuel use by 2030, but a full replacement fuel must first gain approval for all aircraft. Officials indicated in July that this schedule could face delays.

A large share of leaded fuel at MYF, the FAA code for the city-owned airfield, supports flight schools such as Coast Air, which trains pilots from around the world. Planes release roughly half their exhaust during takeoff and landing, and trainees often perform repeated touch-and-go patterns. These routes pass over or within two miles of more than 30 schools.

Due largely to flight school activity, non-military operations at the airport nearly doubled over the past decade compared with the prior ten years.

A 2024 Colorado study found that emissions from leaded aviation fuel produce a small yet notable rise in blood lead levels among children living within two miles of an airport. An earlier Santa Clara County review showed peak-hour lead levels at half those recorded during the height of the Flint water crisis.

Despite high lead levels near Montgomery-Gibbs, the San Diego County blood lead prevention program performs no targeted testing in surrounding communities. State rules call for such testing among children at greatest risk of lead poisoning.

'If they do not like it, do not fly the plane'

A county spokesperson noted that fliers at health fairs urge parents to seek tests for their children, but further steps rest with providers and parents who notice concerns. Symptoms can include learning and behavior issues.

While the EPA tracks flight data and lead estimates, it has not required testing or probes into effects on communities around the nation's top emitter. For over a decade, residents near the airfield have urged officials to curb air and noise pollution from an expanding operation.

They cite Santa Clara County, which banned sales of leaded fuels. The FAA sued, claiming the move violated grant terms. A county spokesperson said it is finalizing an agreement with the FAA to keep its no-sale policy for public health reasons.

Many residents near MYF say officials aware of the risks still permit growth, tying community health to shifting deadlines. San Diego resident Robert Germann has spent nearly 15 years pressing for cleaner air and criticizing local inaction on a worsening public health matter.

He argues the city should require unleaded fuels already available, especially for profit-driven users like flight schools. The current option costs more and offers less convenience, yet he insists community health comes first. "If they do not like it, do not fly the plane," he said. "It is up to the owner to ensure the plane runs safely on unleaded fuel, or it stays in the hangar."

'More decisive action is necessary'

Officials have discussed ending leaded fuels since 2011, yet delays persist and federal rules have blocked local efforts. The FAA formed a task force that year, and by 2016 it projected approval of an unleaded fuel within two years. Deadlines passed, and the current EAGLE program targets 2030 for a ban.

Earlier this year, the California Air Resources Board urged the FAA to speed approval of a standard fuel and set firm rules. With only four years left and no clear milestones, the letter stressed that stronger steps are needed to meet the 2030 goal.

The FAA issued its plan without mandates and required funded airports to keep leaded fuel available until a replacement is fully approved. Some cities have challenged this, citing studies on local impacts. In California, Santa Clara County banned leaded fuel sales at two airports, while Torrance restricted touch-and-go landings. In 2023 the EPA found aircraft lead emissions endanger health, and in 2024 Governor Gavin Newsom signed a statewide ban effective 2031.

Jorge Rubio, the city's airport chief, said introducing unleaded fuel two years ago addressed community worries. He backs the 2031 ban but notes legal issues with the FAA make further steps complex. Low sales stem from higher costs and industry hesitation over new safety and performance factors, he added. The city now shares data to encourage pilots, highlighting easier maintenance and longer engine life with unleaded options.

Ray Richmond, president of Crownair Aviation, said a fully compatible, affordable alternative is needed before sales rise. He believes the FAA must drive the shift. Safety and liability remain key, and he suggested an insurance fund could speed adoption by protecting all parties. As expansion plans move forward, the fuel depot will include space for the eventual FAA-approved fleet fuel.

City expansion plan raises questions

Even with limited unleaded fuel success and record leaded sales, the city advances expansion plans for Montgomery-Gibbs. The master plan includes lead data that should have prompted monitoring by the county air district, yet none occurred. It also indicates EPA estimates may understate actual pollution at the site.

Based on a 2017 study, the plan reports over one ton of lead emissions in a single year, exceeding the EPA threshold for required air monitoring. Local officials confirmed no lead sampling has taken place at the airport. The plan further notes that more than 93 percent of the fleet is piston-powered and burns leaded fuel, compared with the EPA assumption of 72 percent at typical general aviation airports. This gap suggests higher lead output than federal figures indicate.