University of Auckland researchers say anaesthetic gases released annually by a single hospital in New Zealand have the same carbon footprint of 500 return plane journeys between New Zealand and London. The good news, they say, is they have developed a way to capture those gases and dispose of them in an environmentally benign way.
The engineering faculty was approached by concerned anaesthetists at Middlemore Hospital, as anaesthetic gases are greenhouse gases, some of them hundreds to thousands of times more potent than carbon dioxide.
The main gases used in New Zealand are sevoflurane and desflurane, halogenated ethers that are usually administered with oxygen or nitrous oxide, or a mixture of both. More than 95% of anaesthetic gases given to patients are expelled into the atmosphere. Liquid anesthetics were not a viable alternative as up to 50% of liquid anaesthesia drugs are sent to landfill, polluting the environment and posing a high risk of water contamination.
High temperature incineration was currently the only way to dispose of pharmaceutical waste but wasn’t permitted in New Zealand, head of the waste and biomass processing team, Dr Saeid Baroutian said. It was a matter of time before Europe declined to take New Zealand’s pharmaceutical waste products, he added.
The team has developed a new adsorptive and hydrothermal deconstruction method to release anaesthetic waste into the atmosphere after using hot, pressurised water to break it down into safe, inert compounds (mainly water) and organic acids such as acetic acid.
