Airplanes are now the largest source of lead pollution in the United States. A new study suggests Americans hurt by lead exposure may be suffering billions in lost wages.
The issue: Decades of research have shown how lead correlates with aggressive behavior, lower intelligence, learning problems in children and lower earnings later in life. Cars used leaded gas until the Environmental Protection Agency (EPA) mandated it be phased out in the 1980s. Federal law banned lead in house paint in 1978. Scientists have not identified any safe amount of lead in children’s bloodstream.
Some researchers believe that the fall in murders in the 1990s is associated with the declining use of lead over the previous 20 years, that fewer children exposed to lead in the early 1980s meant a smaller number of violent young people hitting the streets in the 1990s.
Nowadays, we often speak about lead when there’s a big story – like the Flint water crisis or the traces found in small-town armories that are used as sports facilities. But across the country, lead remains a persistent concern – in our air.
Most commercial airplanes use unleaded jet fuel. But piston-driven aircraft – generally small propeller planes – use aviation gasoline (“avgas”), which contains lead to prevent a chance of sudden engine failure. That’s 167,000 planes in the United States, according to the Federal Aviation Administration (FAA). Avgas is the only transportation fuel still used in the U.S. that contains lead. Fuel manufacturers have experimented with lead-free avgas for decades, but have yet to bring such a fuel to market. The FAA intends for most aircraft to use an unleaded replacement by 2018.
An academic study worth reading: “Cost of IQ Loss from Leaded Aviation Gasoline Emissions,” in Environmental Science and Technology, 2016.
Study summary: Philip J. Wolfe and his colleagues at MIT look at the amount of leaded avgas used in the continental U.S. in 2008 (248 million gallons) to calculate aviation-attributable lead concentrations in the atmosphere. With those amounts, they calculate the IQ impact on children and then estimate, when those children grow up, the economic impacts from their lower IQs.
Based on government earnings data, they determine a static estimate (the net present value of future earnings reductions) and a dynamic estimate (the impacts of the children’s IQ loss on the economy as a whole). Overall, Wolfe and his colleagues examine three cases based on different airborne lead-exposure levels, offering a broad range of dollar figures and insight into the marginal costs of lead exposure.
Findings:
- At current average airborne-lead levels caused by the planes, the average cost to the American economy is $1.63 billion annually (calculated with a 3 percent discount rate over 15 years). That is the value in lost productivity.
- To American individuals suffering lower IQ from lead exposure, the annual cost in lost wages is a combined $1.06 billion. (Some of the researchers’ models put the total figure as high as $11.3 billion.)
- Avgas is responsible for “a wide dispersion of low concentrations of fine particulate lead emissions.”
- Airborne lead particles fell 94 percent between 1980 and 2013 as lead was phased out of automobile gasoline.
- Relative to gasoline, aviation fuel was an “insignificant source” of airborne lead during the 1960s and 1970s, when driving cars with leaded fuel peaked. Today — along with lead dust in soil from the period of peak leaded driving, as well as residual lead paint — aviation fuel is one of the most significant sources of lead.
Other research:
Among the many papers testing the relationship between lead and aggressive crime is this 2016 study in Environmental Health.
A 2013 EPA study, the Integrated Science Assessment for Lead, reviews the vast research on airborne lead exposure and the history of American efforts to remove the element entirely from the environment.
Several papers have looked at the economic benefits that seem to be correlated with the elimination of lead from gasoline.
Water packaged in glass bottles contains 26-57 times more lead that waters bottled in plastic, though those lead levels are still far below amounts allowed in Europe and North America, according to a 2012 study in Environmental Health Perspectives.
A widely cited 2003 paper found children more sensitive than adults to the negative health effects of lead.
Journalist’s Resource looked at the physiological effects of lead poisoning and American health policy in light of the Flint emergency that started in 2014 and caught national attention in 2016.
Other resources:
The FAA hosts data on general aviation, airport and fuel use, and industry forecasts. This 2013-2033 forecast includes data on the future consumption of leaded avgas.
The Aircraft Owners and Pilots Association (AOPA) is a large advocacy and education organization for pilots.
Keywords: neurotoxicity, poisoning, lead, inequality, children, pollution