Surgical anaesthesia is eating the ozone layer, study says

Anaesthetic gas used for surgery in the U.S. is as bad for the environment as the carbon emissions from a million cars, according to NASA researchers.
Written by Andrew Nusca, Contributor

Next time the doctor puts you under, consider this: anaesthetic gas used for surgery in the U.S. is as bad for the environment as the carbon emissions from a million cars.

That's as much as one coal-fired power plant.

That's according to chemists at the University of Copenhagen and NASA, who say that anaesthetic gasses have a global warming potential as high as some banned refrigerants.

The catch: docs are not obligated to report the impact of anaesthetic gasses, unlike CO2, refrigerants and laughing gas.

According to their research -- performed in collaboration with anaesthesiologists at the University of Michigan Medical School -- one kilogram (approx. 2.2 lbs.) of anaesthetic gas affects the climate as much as 1,620 kilos (or about 3,571 lbs.) of CO2.

They write:

Although the increasing abundance of CO2 in our atmosphere is the main driver of the observed climate change, it is the cumulative effect of all forcing agents that dictate the direction and magnitude of the change, and many smaller contributors are also at play. Isoflurane, desflurane, and sevoflurane are widely used inhalation anaesthetics. Emissions of these compounds contribute to radiative forcing of climate change.

To be sure, the amount of gas needed for a single surgical procedure is not high, and it's knee-jerk to think that we'll stop using anaesthesia for the environment's sake. (Go on, try to be sustainable when you're getting a root canal. I dare you.)

But Copenhagen atmospheric chemistry professor Ole John Nielsen is urging surgeons to think before they gas patients, because not all gasses used in surgery are equal.

Though all types are worse than CO2, milder variants such as isoflurane and sevoflurane have global warming potentials of 210 and 510, respectively. On the other hand, desflurane is a climate-killer, leaving 1,620 times as much impact on the climate as CO2.

The researchers studied the gasses in collaboration with Mads Andersen of NASA's Jet Propulsion Laboratories at the Ford atmospheric laboratories in Michigan.

Is anaesthesia as bad at eating ozone as Freon or HFC-134a? Not quite -- Freon's global warming potential is 11,0000; HFC-134a clocks in at 1,300 -- though it's chemically related.

("Impact potential" essentially means how long the gasses hang in the atmosphere; Freon hangs around for a generation, while HFC-134a remains for 14 years.)

But according to the researchers, only sevoflurane should be legal for use as an anaesthetic.

The study was published in the British Journal of Anaestecia.

This post was originally published on Smartplanet.com

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