Proposed Endangerment Finding for Leaded Aviation Fuel: Gary Keller Comments (Revised Version)

The Dr. Lynn Miranda study "A Geospatial Analysis of the Effects of Aviation Gasoline on Childhood Blood Lead Levels" (2008 - 2011) proved that children living near general aviation (GA) airports were being subjected to lead emissions from GA aircraft. She writes: "Our results suggest that children living within 500m of an airport at which planes use leaded avgas have higher blood lead levels than other children. This apparent effect of avgas on blood lead levels was evident also among children living within 1,000m of airports. The estimated effect on blood lead levels exhibited a monotonically decreasing dose-response pattern, with the largest impact on children living within 500m". The "m" is meters.

Her conclusion: "We estimated a significant association between potential exposures to lead emissions from avgas and blood lead levels in children. Although the estimated increase was not especially large, the results of this study are nonetheless directly relevant to the policy debate surrounding the regulation of leaded avgas."

The study was conducted over 6 counties and 66 airports in North Carolina. The aviation gas data was provided by the EPA along with some grant money.

The total combined amount of lead emissions from all 66 of these airports as reported in 2008 was 2.6 tons (5200 lbs.). In 2008, combining the three top 10 lead emitting GA airports in the US would have been more than all the 66 airports in this study.

The EPA knew this as they have National Emissions Inventory (NEI) data going back further than 2008.

Didn't these results scream out for a study to be performed on children that live near a high lead emissions airport as soon as possible? How long should policy be debated when children are being subjected to this harmful toxin? The EPA never intended to repeat a test with blood lead levels of children.

On 1/10/2023 the National Academy of Sciences Journal, Nexus, published, "Leaded aviation gasoline exposure risk and child blood lead levels" by Dr.Sammy Zahran, Christopher Keyes and Dr. Bruce Lanphear. The lead study was first brought to the attention of the general public on Aug 3, 2021. It was conducted at Reid-Hillview airport in San Jose, California. Similar to the Miranda study, blood lead samples were analyzed on the children living near this airport. Reid-Hillview airport (RHV) had about half of the total emissions of the combined 66 airports in the Miranda study. What type of results did this bring?

Instead of a conclusion, Dr. Zahran offers this Significance Statement: "In the United States, hundreds of millions of gallons of tetraethyl lead-formulated gasoline are consumed by piston-engine aircraft (PEA) annually, resulting in an estimated half-million pounds of lead emitted into the environment. About four million persons reside, and about six hundred K-12th grade schools are located, within 500 meters of PEA-servicing airports. In January 2022, the US Environmental Protection Agency launched a formal evaluation of "whether emissions of lead from PEA cause or contribute to air pollution that endangers public health or welfare." In support of the EPA's draft endangerment finding and request of public comment, an ensemble of evidence is presented indicating that the deposition of leaded aviation gasoline significantly elevates the blood lead levels of at-risk children".

According to EPA data, there are actually 1 million pounds of lead emitted each year into the environment by GA aircraft.

Since the Miranda study, millions of dollars have been spent on air monitoring and quantifying airport lead emissions.

The modeling for how lead emissions were calculated was changed during the Miranda study and now airports were showing less lead emissions.

It doesn't matter how many air samples that were taken or modeling that was changed, if the children still had lead in their blood, how meaningful were they?

Even the 2021 "Options for Reducing Lead Emissions from Piston-Engine Aircraft" from the National Academy of Sciences (NAS) fell far short with their recommendations for the removal of this toxic substance. There is no further testing that needs to be done. There is only one logical option for reducing leaded emissions – stop using it!

Now, not 8 years from now.

Had the Dr. Zahran study been performed right after the Dr. Miranda study, the EPA should never have received a 2nd or a third Petition for Endangerment Finding. There would have been no need as the first one would surely have been the last.

Would the overwhelming evidence of this study have caused the National Ambient Air Quality Standard (NAAQS) to be lowered again in 2016? How would the Clean Air Scientific Advisory Committee (CASAC) have weighed the Reid-Hillview study?

The EPA needs to stop pretending that they care about the federal standards for mobile sources of air pollution and their fuels through the Clean Air Act.

The GA industry needs to stop pretending that they're not poisoning our children. The FAA finally stopped pretending that they never had the unleaded fuel that all these planes could use in 2022 as it was offered for certification back in 2010.

To allow the continued use of AvGas, the GA industry needed more than the mega dollars appropriated from Congress, which are our tax dollars. They needed more than the FAA's refusal to certify GAMIs G100UL unleaded fuel that was available since 2010. They needed to be sheltered from the Clean Air Act. They needed compliance and acts of omission from the EPA. And they got it.

Not to reach an endangerment finding would be to continue the most abject failure of the EPA in their history.