Plane Exhaust Kills More People Than Plane Crashes [National Geographic News]
[National Geographic News, 10/10/10]
There’s a new fear of flying: You’re more likely to die from exposure to toxic pollutants in plane exhaust than in a plane crash, a new study suggests.
In recent years, airplane crashes have killed about a thousand people annually, whereas plane emissions kill about ten thousand people each year, researchers say.
Earlier studies had assumed that people were harmed only by the emissions from planes while taking off and landing. The new research is the first to give a comprehensive estimate of the number of premature deaths from all airline emissions.
“We found that unregulated emissions from [planes flying] above 3,000 feet [914 meters] were responsible for most of the deaths,” said study leader Steven Barrett, an aeronautical engineer at the Massachusetts Institute of Technology in Cambridge.
Airplane exhaust, like car exhaust, contains a variety of air pollutants, including sulfur dioxide and nitrogen oxides.
Many of these particles of pollution are tiny, about a hundred millionths of an inch wide, or smaller than the width of a human hair.
So-called particulate matter that’s especially small is the main culprit in human health effects, especially since the particulates can become wedged deep in the lung and possibly enter the bloodstream, scientists say.
Tracking Toxic Plane Pollution
Barrett and colleagues used a computer model that brought together records of flight paths, the average amount of fuel burned during flights, and their estimated emissions.
The computer model, based on experimental data, has been shown to accurately capture pollution’s movement in the atmosphere as well as intercontinental transport of pollution, especially from Asia to North America, Barrett said.
By comparing this data with another atmospheric model, the team was able to track how plane pollutants are likely to move and where the pollutants are most likely to fall to the surface, where people breathe them in.
The study also looked at how human populations are spread around the planet to estimate how the patterns of airplane pollution might up the risk of death.