St John’s Hospital in Limerick has become one of the first medical facilities in Ireland to take decisive action against the environmental impact of nitrous oxide emissions by deactivating its central pipeline system for the gas, long used as an anaesthetic. The move is part of a growing effort in the healthcare sector to reduce its carbon footprint and curb avoidable waste.

Nitrous oxide, commonly known as laughing gas, has been used in hospitals for decades to relieve pain and anxiety during procedures. However, studies have shown that large volumes of the gas leak into the atmosphere due to outdated infrastructure, where it can remain for up to 120 years and contribute significantly to global warming.

Dr Hugh O’Callaghan, a consultant anaesthetist at St John’s, explained that while nitrous oxide remains safe and effective for clinical use, its delivery through centralised piping systems leads to “inevitable waste.” Instead, the hospital will now use portable canisters brought directly into operating rooms, a method that reduces gas leakage and emissions.

This initiative aligns with Ireland’s national plan to cut carbon emissions from anaesthetic gases by 50% by 2030. Other hospitals across the country are expected to follow St John’s lead in the coming months, according to the Health Service Executive (HSE).

Similar steps have already been taken in parts of the United Kingdom and the Netherlands. In England, hospitals that replaced central gas systems with mobile units saw a 55% drop in monthly nitrous oxide emissions, according to the NHS. In Manchester, the switch reportedly lowered the local health trust’s overall carbon footprint by up to 5%.

“It’s not about limiting clinical care—it’s about smarter, more sustainable delivery,” said Dr Cliff Shelton, a UK anaesthetist and co-chair of the environmental committee at the Association of Anaesthetists. The group has recommended decommissioning hospital nitrous oxide pipelines across the UK and Ireland by 2027.

Healthcare professionals increasingly acknowledge their sector’s role in climate change. Globally, the health sector accounts for about 4.4% of total emissions, with the European Union responsible for 248 million metric tons of carbon dioxide annually—trailing only the United States and China.

Although nitrous oxide and other anaesthetic gases contribute significantly to this footprint, experts stress that the bulk of emissions stem from the healthcare supply chain, including pharmaceuticals and medical equipment.

Still, efforts like those at St John’s Hospital are seen as important first steps. “When we looked into this, we found we were buying 100 times more nitrous oxide than we were actually using,” said Dr Shelton. “It’s a moral imperative to address that kind of waste.”

A new artificial intelligence (AI) tool could significantly improve outcomes for prostate cancer patients by identifying who would benefit most from the drug abiraterone, according to UK researchers presenting their findings at the American Society of Clinical Oncology’s annual meeting this week.

The tool analyzes tumour biopsy images to detect hidden biomarkers that predict whether a patient is likely to respond well to abiraterone, a drug known to nearly halve the risk of death for some men with prostate cancer. While effective, abiraterone is expensive and carries potential side effects such as high blood pressure, liver issues, and diabetes. These concerns have led health systems to prescribe it cautiously.

“This research shows that we can pick out the people who will respond best to abiraterone, and those who will do well from standard treatment alone – hormone therapy and radiotherapy,” said Professor Nick James, co-lead of the study from the UK’s Institute of Cancer Research.

The AI model was developed by studying tumour pathology slides and identifying molecular markers invisible to the human eye. Researchers then applied the tool to biopsy images from over 1,000 men enrolled in an earlier clinical trial on prostate cancer therapies.

Among patients whose tumours tested positive for the biomarker, abiraterone cut the five-year mortality rate from 17% to 9%. In contrast, those without the biomarker did not show a significant benefit from the drug, suggesting they could avoid unnecessary side effects and rely on standard treatments instead.

“This study shows, in a very large cohort of patients, that novel algorithms can be used to extract information from routinely available pathology slides to tailor these treatments to specific patients and minimise over-treatment whilst maximising the chance of cure,” said Professor Gert Attard of the University College London Cancer Institute, the study’s co-lead.

In the UK, access to abiraterone varies. While it is approved for use in newly diagnosed high-risk patients in Scotland and Wales, England’s NHS only offers the drug once the cancer has spread. The researchers called for policy changes, estimating that up to 8,400 men in England could benefit from earlier access.

“Access to this life-extending drug is currently a postcode lottery,” James said. “Those living in Scotland and Wales can receive the treatment for free — others cannot.”

Prostate cancer remains one of the most common cancers among men, with nearly 336,000 new cases diagnosed annually in the European Union.