Effects from lead in plumbing, paint and gasoline continue to haunt the health and well-being of communities even decades after its widespread use ended, but tons of lead from gasoline are still released each year at general aviation airports throughout the nation, which include three in Oakland County.
The United States Environmental Protection Agency (EPA) began phasing out lead from automobile gasoline in 1973, with a complete removal of lead from the fuel in 1995. However, the vast majority of today's fuel that powers piston-engine aircraft still contains lead.
Used by about 167,000 piston-engine aircraft at some 20,000 airports in the United States, general aviation fuel, or "avgas," is the only remaining lead-containing transportation fuel. Avgas is used in general aviation aircraft with piston engines, which are generally used for instructional flying, air taxi activities and personal transportation. Some helicopters and recreation craft, such as ultralights, may also use avgas. Lead isn't found in jet fuel, which is used by most commercial aircraft.
Piston-engine aircraft account for the largest source of lead emissions in the air in the United States, including industrial sources, such as ore and metal processing facilities. Emissions of lead from piston-engine aircraft using leaded avgas make up about half of the nation's inventory of lead emitted from the air.
In Oakland County, piston-engine aircraft produced more than a half ton of air emissions in 2008, according to the EPA. Those emissions, along with the airport's layout and pressure placed on federal regulators to begin a national phase out of lead from aviation gasoline, forced the county to monitor lead concentrations in the air at it's largest airport, Oakland County International Airport in Waterford, in 2011 and 2012.
The county also owns and operates Oakland Southwest Airport in Lyon Township; and the Oakland/Troy Airport. Additionally, there are more than two dozen helipads, seaports and unregistered air fields where some piston-powered helicopters, seaplanes and ultralight aircraft may operate in the county.
County airport officials estimate there are more than 50,000 annual, combined takeoffs and landings by piston-engine aircraft at its three airports, with about half of those conducted at Oakland County International. By comparison, the airport registers about 100,000 commercial jet takeoffs and landings each year.
David VanderVeen, airport spokesman and director of central services for Oakland County, said the total number of flights at Oakland County International Airport have dropped from about 390,000 takeoffs and landings in 1988 to about 120,000 annually now. The biggest decline in operations, he said, is with smaller, piston-engine planes that use leaded gas.
"The EPA did a study on lead emissions a few years ago," he said. “They determined our lead emissions – and they had some sophisticated instruments in the field – the lead levels were about half of the concern levels."
Results from that study, provided in this article, confirm VanderVeen's assessment. However, human health and environmental groups say there is no safe level of lead when it comes to the public's safety.
"As we have seen, we continue to have significant problems with lead in our environment, whether it's legacy issues from paint and water pipes or from lead in gasoline. We still have lead from automobile gasoline in our environment," said Marcie Keever, legal director for Friends of the Earth, an environmental activist group that has pushed for the EPA to phase lead out of avgas.
High levels of exposure to lead can result in death and brain damage. But even low exposure to lead has been found to cause learning disabilities, lower IQ levels, increased blood pressure and nerve damage. Children are specifically at risk to lead exposure because they absorb larger amounts of lead and are more sensitive to lead induced toxicity.
Lead in the air can spread far from where it is produced. Once airborne, it may be ingested into the lungs or fall to the ground and mix with the soil, where it remains until it is disturbed. Because babies and young children are more likely to put their hands and other items exposed to lead dust or soil into their mouth, lead contaminated soils pose a higher risk to them.
A 2011 study by researchers at Duke University looked into the effects of avgas on childhood blood levels in six counties in North Carolina. The study suggested children living within one-third of a mile to an airport where leaded avgas is used had higher blood lead levels than other children. The study suggested lead emission from avgas may contribute to blood lead levels in children living more than half a mile away from the same airports.
Yet residents living closest to general aviation airports may have no knowledge of the potential risk to their health from piston-engine aircraft. More often than not, concerns about piston-engine aircraft are overshadowed by their larger, noisier jet-powered counterparts.
Waterford resident James Hardin, who has lived within a mile of the airport for about 60 years, said he wasn't aware that aviation fuel contains lead.
"I thought it was all lead free today," said Hardin, who is concerned about the diesel-like fumes he endures from jet exhaust. "We really notice it when the wind comes from the airport out of the north. When it drops, it just gags you. It's hard to explain. I'm hyper-sensitive to it. I have to leave sometimes. Diesel is nasty and sooty. You get a black film on everything. I have a skylight on my house and it gets terrible, especially in the winter. You have to wash it a lot.
"I would be concerned more about the diesel than the avgas. You don't smell the airplane gas."
Unlike jet fuel that has a strong odor and can leave behind a dark residue on windows, walls and patios and outdoor furniture, avgas exhaust is more akin to automobile exhaust. While aviation fuels are formulated to have increased stability for flight, unleaded avgas is available at limited airports and is similar to 94-octane auto fuel. However, the majority of avgas includes a lead additive, which provides an octane boost required by many airplane engines.
"Performance is the key benefit and reason why lead was added to fuel; it adds a significant amount of performance increase to the engine, and specifically it has an anti-detonation measure," said Walter Derosier, vice president of engineering for the General Aviation Manufacturers Association. "If it starts to detonate inside the engine cylinders, it is extremely damaging."
David Oord, director of government affairs for the Aircraft Owners and Pilots Association, said about 70 percent of the existing piston-engine aircraft today can operate on a version of unleaded, ethanol-free fuel if they acquire the proper certification. However, about 30 percent of planes still require a higher octane fuel that is currently only available in leaded form.
Records obtained through a Freedom of Information Act request by Downtown Publications show just 15 complaints were made from 2006 to 2013 to the Oakland County International Airport regarding odor, residue and noise from jet aircraft. While the majority of complaints referenced concerns about health impacts from breathing exhaust fumes, none of the complaints involved piston-engine aircraft. Instead, the complaints targeted commercial jets and jet fuel fumes that are similar to diesel fuel.
Residents who registered complaints said the smell of jet fuel was overwhelming. One person who called the airport to complain said the fumes are so bad that when he and a friend were sitting in his backyard, "They made his friend regurgitate on the lawn."
Keever, with Friends of the Earth, said it was actually nitrogen oxide levels from turbine-powered aircraft that the group was hoping to convince the EPA to address when researchers learned lead fuel was still being used in the industry.
"It's sort of like we found it. We were looking for another thing in the Clean Air Act about another source and we found it," she said.
Had the group not been investigating greenhouse gas emissions from turbine engines, Keever said it's unlikely the EPA would even be considering plans to phase out lead from aviation fuel.
"As soon as we discovered this in 2003, we wrote to the EPA, and they didn't do anything," she said. "We sent them a petition and filed litigation in 2012 because they haven't replied to our petition."
The petition requested the EPA begin a process to remove lead from aviation gas by finding that lead emissions may reasonably be expected to endanger public health and welfare, and for the agency to propose new lead emission standards in the federal Clean Air Act.
"They have said they will do an endangerment finding, which is the first step in phasing out lead in avgas," Keever said.
The EPA is now evaluating the impact of emissions from avgas on public health. The agency also intends to release their findings in 2017 for public review and comment. A final endangerment finding is expected to be released in 2018, following a review of public comments.
"General aviation, or piston-engine aircraft, is the single largest source of lead emissions in the United States," Keever said. "It's continuing and ongoing."
About 34,000 tons of lead emitted from piston-engine aircraft have been released into the air in the United States between 1970 and 2007, according to the federal Environmental Protection Agency (EPA).
The Oakland County International Airport, in Waterford, which houses nearly 400 piston-engine aircraft, registered .59 tons of lead emissions in 2008, making it one of 58 General Aviation airports in the nation to have a half-ton or more in lead emissions that year, according to EPA records. Just six airports across the nation in 2008 had annual lead emissions greater than one ton.
To put lead emissions into context, consider that the EPA requires state and local air quality agencies to monitor lead concentrations in the air near industrial facilities with estimated lead emissions of .5 tons or more per year. Airports releasing a full ton or more of lead also are required to be monitored. However, monitoring requirements are applied on a case-by-case basis in locations where the EPA determines there is a likelihood that annual lead emissions could result in those locations exceeding the agency's ambient air standard.
The EPA's National Ambient Air Quality Standard is what determines acceptable lead concentrations levels in the air in locations accessible to the general public. While total lead emissions are measured in tons, concentrations are measured by monitoring the micrograms per cubit meter of total air over a three month timeframe.
In 2008, the EPA strengthened the ambient air standard for lead, revising the maximum from 1.5 micrograms per cubic meter to .15 micrograms. Those concentrations represent a three-month average of lead levels in total suspended particles.
In 2011, Oakland County International Airport was one of 17 airports in the United States required by the EPA to participate in a 12-month monitoring program to gauge lead concentrations of outside air where the general public would have access.
Under the program, airports with a three month average lead concentration exceeding the .15 micrograms would be required to have continued monitoring beyond the initial year of testing. The .15 microgram average is the maximum under the National Ambient Air Monitoring Standard.
Monitoring at the Oakland County International Airport took place from July 2, 2011 through August 7, 2012. An air monitoring station, about the size of a mailbox, was placed downwind from the main runway where the majority of piston-engine aircraft takeoff. Results show lead concentrations for five or six days each month, with average lead concentrations for each day, the average monthly concentration and a three-month average.
Results from the study show the highest three-month average lead concentrations at the Oakland County airport reached a maximum of .02342 micrograms for the months including August, September and October of 2011, well below the .15 microgram standard of the NAAQS. The highest monthly average recorded in the study was .0277718 micrograms in August of 2011. The maximum daily lead concentration for the year was .04108, on October 30, 2011.
“As you can see, the three month rolling average remained below .075 micrograms per cubit meter (i.e., one-half of the National Ambient Air Quality Standard)," an air monitoring supervisor with the Michigan Department of Environmental Quality's (DEQ) Air Quality Division, which conducted the monitoring on behalf of the EPA, said in a memo to airport officials on August 28, 2012. "As we have collected a complete year of data, the requirements laid out in the Federal Register have been met and we have stopped collecting samples.”
Included in the monitoring program were airports that had lead emissions between .5 and one ton per year, based on 2008 lead emissions recorded by the EPA's National Emissions Inventory. The goal, according to the EPA, was to better understand how the lead emissions from avgas affect the air at and near the airports. In total, there were 58 airports that produced at least a half ton or more of lead emissions, but less than one full ton.
To scale down the number of airports in the monitoring program, the EPA took into consideration the airport runway configuration and meteorology that would cause a greater frequency of operation from one or two runway ends.
Finally, the EPA looked for airports where ambient air is within 150 meters of the location where the maximum amount of lead emissions would be released. Ambient air is any location to which the general public has access. On airports, the general public includes recreational pilots and their passengers, members of the public who visit the airport for special events and other people who might be in airport hangars.
“We selected a distance of 150 meters between the maximum impact site and ambient air because the available information suggests that ambient air concentrations will decrease sharply with distance from the source and it is less likely that an exceedance of the NAAQS for lead will occur at greater distances,” EPA officials with the National Vehicle and Fuel Emissions Laboratory in Ann Arbor said in a memo to airports.
The EPA said its 150 meter location was based on monitoring conducted at the Santa Monica Airport, in California.
Airports included in the study that exceeded the .15 microgram standard and required additional monitoring included the McClellan-Palomar Airport, in California (.17 micrograms); and the San Carlos Airport, in California (.33 micrograms).
The Palo Alto airport, which had an average lead concentration of .12 micrograms, was the third highest of all the airports included in the study.
"The lead gradient at this airport serves as a guide for the purpose of limiting the number of airports to consider for this exploratory airport monitoring study," the EPA said. "We are not implying that there will be no exceedances of the NAAQS for lead beyond the 150 meter distance."
Oakland County Manager of Aviation Karl Randall, in a September 2011 email to EPA regulators, expressed disagreement with the agency's monitoring location at the airport, which was located about 10 feet south of the south end of an airplane hangar on the northeast side of the runway, and about 90 feet north of the center of the runway.
"I do not believe it is at all appropriate to include recreational pilots, their passengers, or hangar tenants within the definition of the general public. Realistically, consideration ought to be given to the legal principle of assumption of risk," he wrote. "Pilots operating aircraft, their passengers and hangar tenants (who are also pilots) are fully aware of the presence of engine exhaust from their and others' planes, and voluntarily choose to be there."
Randall also said other than those specific people at the airport, operational procedures in place by the Federal Aviation Administration (FAA) restrict the public from the area where the monitoring was to be conducted.
"This monitor site location is clearly designed to present the worst possible case scenario, not of realistic assessment of what lead levels the 'true' general public might be exposed to, a minimum of hundreds of feet or yards away from aircraft takeoff and preflight run-up check locations," he said in the email. "If the underlying concern and justification for conducting the study is the actual level of lead exposure to the general public from piston powered planes burning 100LL, the monitoring should be done out in the community where the people are – not on the airport virtually at the exhaust pipe of the aircraft."
Susan Kilmer, unit supervisor for the Michigan DEQ's Air Monitoring Unit, said the EPA chose that specific monitoring location at the airport based on its proximity to the rev-up zone for airplanes and wind direction. She said one such monitor can't show lead levels reaching the public outside of the airport grounds.
"If we we're doing ambient air sampling in a community, we would need to be a certain distance from the roadway because the objective is measuring ambient air that the public will breathe, so we would want to be away from obstructions, but this was to monitor what was coming off small aircraft," Kilmer said. "I would think that being very close to the runway, where they are revving up before they start rolling, I would expect that to be the maximum impact location, and that it would dilute the further away from the airport."
However, the height at which lead emissions are released may have a substantial impact on how far lead particles travel in the air. Kilmer said this became evident in monitoring lead emissions at a brass production facility in Belding, Michigan. When the facility raised the height of its smoke stack, the DEQ had to add a second monitoring location to track the emissions.
"Disbursement is dependent on the height of the stack, the air velocity and weather conditions," she said.
While monitoring at the airport gives a small snapshot of lead concentrations at a specific location, the total impact of lead emissions is more of a moving target.
In addition to the EPA's ongoing work into lead emissions from piston-engine aircraft, the Federal Aviation Administration is working with the aviation industry to establish a new standard of unleaded fuel that will work across the existing general aviation fleet.
Under the partnership, the Piston Aviation Fuels Initiative (PAFI) was formed, which includes representatives from the FAA, pilots, aircraft owners, aircraft manufacturers and others. Additionally, Congress has approved $7 million for the 2016 fiscal year to support PAFI's testing program at the FAA's William J. Hughes Technical Center in Atlantic City, New Jersey.
As part of the initiative, the FAA in June 2013 requested fuel producers to submit replacement fuel proposals to the FAA for evaluation. Testing of 17 formulations from six different companies was done, and reduced to four formulations for the first testing phase, which was completed in December 2015. The FAA and PAFI are now conducting the second phase of testing, which involves two unleaded fuels and ground and flight testing using more than two dozen engine and aircraft models.
Ken Knopp, a manager at the FAA's technical center in Atlantic City, said testing is on schedule to be completed in 2018. At that point, he said, the hope is that the FAA will certify one or both of the fuels for use.
Oord, with the owners and pilots association, said the industry is concerned about lead emissions, and is working with the FAA to come up with a safe alternative to leaded fuel.
"Ultimately, it's hard to defend lead," he said. "It's a pretty toxic substance. I think we all agree that it's in our best interest to move froward and test and approve a replacement."
The number of piston powered airplanes flying in and out of the Oakland County International Airport, in Waterford, caught the attention of federal regulators in 2011, but for residents living near the airport, the main concern has centered around the overpowering smell of jet engine exhaust.
In March, a Waterford resident contacted the Michigan Department of Environmental Quality (DEQ) to find out more about lead emissions from smaller piston-engine airplanes, and to ask whether he should be concerned about air pollution from jets.
"I can frequently smell jet fuel in my neighborhood, which causes me to be concerned for the health of my children," the resident said in a March 14, 2012 email to Craig Fritzner, supervisor at the Air Monitoring Unit of the DEQ.
"I'm sorry, but I am not familiar with the components of jet fuel, nor do I know what the latest studies across the nation have shown about the role jet engine emissions have upon air quality. However, I will ask my colleagues at the U.S. Environmental Protection Agency (EPA) if they have such information," Fritzner responded.
As it is, aircraft, specifically jet and turbo prop-powered planes, are the single-largest greenhouse gas-emitting transportation source not yet subjected to greenhouse gas standards in the United States, according to the EPA.
In July of 2016, the agency finalized findings under the federal Clean Air Act, stating that concentrations of six well-mixed greenhouse gases in the atmosphere endanger the public health and welfare of current and future generations; and that greenhouse gasses emitted from certain classes of engines used in certain aircraft are contributing to the air pollution that endangers public health and welfare.
The result of domestic and international flights originating in the United States account for 12 percent of greenhouse gas emissions from the nation's transportation sector; about three percent of total greenhouse gas emissions in the country; and a half percent of total greenhouse gas emissions around the world.
Specifically, the EPA singled out six greenhouse gasses related to jet and turboprop engine exhaust, which include carbon dioxide; methane; nitrous oxide hydroflourocarbons; perfluoracarbons; and sulfur hexaflouride. The six compounds are considered as a combined group and together are the cause and best understood drivers of human-induced climate change, and the results' impact on public health and welfare.
Despite the findings, the EPA isn't yet proposing or finalizing aircraft engine emission standards for greenhouse gases. Rather, the findings are considered the first step toward those standards.
"These findings trigger the EPA's duty under the Clean Air Act to promulgate emissions standards applicable to GHG (greenhouse gas) emissions from the classes of aircraft engines included in the contribution finding," the EPA said in a statement. "Any such future proposed domestic regulatory actions would be open to the appropriate public comment and review, providing opportunity for stakeholders and the public to provide input."
The investigation into jet engine emissions stems from a petition filed in December of 2007 by environmental groups, including Friends of the Earth, Oceana, Center for Biological Diversity, and Earthjustice. In its petition, the groups requested the EPA make findings that greenhouse gas emissions from aircraft engines may endanger public health and welfare.
The groups have said the EPA didn't begin evaluating emissions from airplane pollution until 2014, shortly after they had filed a notice of intent to sue the agency for failing to reduce aircraft emissions.
The groups say the EPA hasn't done enough to reduce aircraft emissions. A study by the International Council on Clean Transportation found the top 20 transatlantic air carriers are able to lower greenhouse gas emissions as much as 51 percent by using existing technology and operational improvements.
"The endangerment found in the documents the magnitude of airplanes' contribution to climate change, but the EPA fails to take steps to address the harms," said Sarah Burt, staff attorney at Earthjustice. "We will continue to use the power of law to compel the EPA to put in place standards that actually reduce harmful pollution from aircraft."