Piston engine aircraft pose possible threat.

• Position: Lead Poisoning

They may seem innocuous enough, those small planes used for weekend getaways, flight training, small freight deliveries, and other civilian purposes but, collectively, the more than 167,000 piston-engine aircraft that comprise the majority of the U.S. general aviation (GA) fleet may pose a significant health threat--these vehicles, which rely on leaded fuel to operate safely, constitute the nation's largest remaining source of lead emissions.

Those who are exposed to low levels of lead, especially children, have been shown to suffer neurological and cognitive impairment, including IQ loss.

Unlike commercial airliners, which do not use leaded fuel, and automobiles, which went all-unleaded by 1995, piston-driven GA aircraft account for about half of anthropogenic lead emissions in U.S. skies--but just how much of an impact is this airborne lead having on the nation's public health and economy?

To answer that question, a team of researchers from the Massachusetts Institute of Technology, Cambridge, conducted the first assessment of the nationwide annual costs of IQ losses that can be attributed to aviation lead emissions. The team found that each year, these IQ losses result in about $1,000,000,000 in damages from lifetime earnings reductions, with an additional $500,000,000 in economy-wide losses due to decreases in labor...