ARE WE LETTING LEADED GAS BACK INTO OLDHAM COUNTY?

 

Lead Content in Avgas Poses Major Health Concern

Our discussion about a general aviation airport for Oldham County has focused on economics, the impact on property values, and the impact of noise pollutions.  However, the lead content in general aviation gas, poses a major health concern that must be addressed.

The phase out of leaded gas began in 1975 and it was completely banned by the EPA in 1996.  However, this ban applied only to trucks and automobiles, not piston-driven general aviation aircraft.  So, for the past 12 years, general aviation aircraft have continued to burn leaded aviation gas (avgas), and emit lead into our environment.  While the FAA has been working to replace avgas with unleaded fuel, it has been doing so for over 20 years.  Unfortunately, there is no indication that a workable solution will be forthcoming in the near future.  In fact, in May of 2008, Aircraft Owners and Pilots Association, urged caution in imposing further restrictions on the use of lead in aviation gasoline, stressing that no simple alternative exists for leaded aviation gasoline (1). 

It is not the intent of this paper to discuss the political rationale for the EPA’s decision to exclude general aviation aircraft from the original leaded fuel phase out, why the EPA has failed to set a lead emission standard for aircraft, or why the FAA hasn’t been able to come up with a viable alternative fuel for general aviation aircraft.  It is the intent of this paper to provide factual information about lead, its effects on our children, and how much lead is being emitted by general aviation aircraft.

How does lead affect our children?

I think we can all agree that lead is harmful to the human body.  However, it is our children who are most at risk because they begin to suffer ill effects from lead at very low exposure levels.  Here’s why:

1.     Children often put their hands and other objects in their mouths that can have lead contaminates, such as dirt, food, and toys (2).
2.         A child’s growing body absorbs more lead—about 40 -50% more than an adult’s body (3).
3.        Children’s brains and nervous systems are more sensitive to the damaging effects of lead.

What Are the Effects of Long-Term Lead Poisoning?

Lead poisoning may lead to a variety of health problems in children, including:

1. poor muscle coordination
2. decreased bone and muscle growth
3. damage to the nervous system, kidneys, and/or hearing
4. speech and language problems
5. developmental delay
6. seizures and unconsciousness (in cases of extremely high lead levels) (3)

How much is too much lead exposure?

Back in the fifties and sixties, the American medical community generally felt that a person could absorb about 60 micrograms of lead (a microgram is one millionth of a gram) per one-tenth of a liter of blood before demonstrating signs of lead poisoning, such as convulsions.  Since the average adult has about 5 liters of blood, a grown person could absorb about 3000 micrograms of lead before showing signs of lead poisoning.

By the nineties, the Center for Disease Control, the American Academy of Pediatrics, the EPA and the National Academy of Sciences have agreed that the ill-health effects begin when an adult body absorbs 10 micrograms of lead per one-tenth liter of blood, or about 500 micrograms of lead in the body (4).

How much lead do General Aviation aircraft emit?

·         In every gallon of avgas, there is 2.1 grams of lead, according to Shell Oil, a producer of avgas.   Lead is not consumed in the engine combustion process, so it is exhausted into the environment.

 

·         In 2002, the EPA’s National Emissions Inventory (NEI) estimated the annual emissions from the use of leaded aviation gasoline amounted to 491 tons, which represents 29 % of all the leaded air pollution emissions (5).  While this fact is sobering, it isn’t particularly useful because it doesn’t tell us how much lead emissions occur over Kentucky.

 

·         In May, 2008, the EPA’s Office of Transportation and Air Quality, the EPA published a revision to the NEI (6).  This new document estimated the annual amount of lead emissions for piston-engine powered aircraft at over 3,000 airports across the U.S.  However, the EPA only estimates the lead emitted during the takeoff and landing phases of flight.  So, much of the lead emissions generated by aircraft (engine runs, cross country flights, or basically, any flying done away from an airport) still goes unreported and unmeasured.  While the EPA’s newly revised document falls short in measuring the total amount of lead pollution, it does give us an idea of the potential lead exposure in and around airports. 

 

o   In the Commonwealth of Kentucky, during takeoffs and landings, general aviation piston-powered aircraft produced over 4,000 pounds of lead emissions annually. 

 

o   Bowman Field accounts for over 475 pounds, which is the second highest amount in the state. 

 

It would be nice to believe that all this lead simply goes away. Fortunately, part of the lead emissions break down quickly.  Unfortunately, other lead particles can hang around for a long time.

 

What happens to the lead emissions from general aviation aircraft?

Some lead particles (inorganic lead & lead halides) can remain airborne for about 10 days, and can be transported far from the original source (7).  Eventually, lead particles will be deposited on soil and water surfaces.  In the soil, lead does not break down rapidly.  In water, lead attaches to other sediments.  Lead particles can just as easily land on playground equipment, sandboxes, bicycles, and anything else found outdoors.

Is there really a risk associated with lead emissions?  Here’s what the EPA says:

“Lead particles can remain airborne for some time following the initial introduction into the atmosphere. Therefore, residents in the vicinity of [auto] race tracks and general aviation airports where leaded gasoline is still being used as fuel may have an increased risk of lead exposure,” (8)

 

To say that lead emissions from general aviation aircraft are not a serious problem would be a disservice to the residents of Oldham County.  If our fiscal court decides to build an airport in Oldham County, then a by-product of this decision is an increased risk of lead exposure for those who live near the airport.

 

 

References

1.  “AOPA, Greens Battle Over Lead in Avgas,” Kerry Lynch, The Weekly in Business Aviation, Mar 24, 2008.

2.  “Lead Compounds Hazard Summary,” U.S. EPA (April 1992, modified January 2000), available at http://www.epa.gov/ttn/atw/hlthef/lead.html.

 

3.  “The Secret History of Lead, “Jamie Lincoln Kittman, from The Nation, Mar 20, 2000.

4.  “Lead Poisoning, Dr. Kate M. Kronan, “Kid’s Health”, June 2006, available at http://www.kidshealth.org/parents/medical/brain/lead.

5.  EPA National Emissions Inventory, 2002.

6. “Revised Airport Specific Lead Emissions Estimates,” Memorandum from Hoyer, Manning, and Irvine, USEPA to the Lead Ambient Air Quality Standards Docket, dated May 14, 2008, Table 1.

7.  Persistent, Bioaccumulative, and Toxic Program, National Action Plan for Alkyl-lead, U.S. EPA, June 2002.

8.  NASCAR scheduled all its series racing to use lead free fuel by the end of 2007.