28 May 2025

Menna Zayed

Climate change is listed by the World Health Organization (WHO) as an urgent health challenge for the next decade.¹ Anthropogenic global warming gives rise to extreme weather events and air pollution, in turn negatively affecting peoples’ health. These greenhouse gas (GHG) emissions contribute to more than one-quarter of global deaths from heart attacks, strokes, lung cancer and chronic respiratory disease.¹ Furthermore, the WHO reports that climate change will result in an additional 250,000 deaths annually between 2030 and 2050 due to malnutrition, malaria, diarrhea and heat stress.² In Canada, more than 20,000 premature deaths each year are attributable to air pollution.³ Children, the elderly and those with preexisting medical conditions are among the most vulnerable.² Health care is a major contributor to GHGs. In Canada, the health care system produces 4.6% of the national GHG emissions, which is comparable with that of the United Kingdom, Australia and the United States (3%-4%, 7% and 9%-10%, respectively).³ These Canadian health care GHG emissions are a result of public hospitals (22%), prescribed drugs (21%) and physician services (13%).³ Prescribed and non-prescribed pharmaceuticals together represent 25% of the total health care GHG emissions, the largest of any category.³ Upstream economic activities, such as energy, pharmaceutical manufacturing or transportation, are responsible for 90% of these emissions.³ Pharmaceuticals produce GHGs throughout their life cycle by means of manufacturing, procurement, transportation, packaging, disposal through incineration and the use of drugs themselves. Metered-dose inhalers (MDIs) and inhaled anesthetics are particularly carbon heavy, accounting for 4% and 2% of the UK National Health Service’s (NHS) overall carbon footprint, respectively.⁴ The hydrofluoroalkane propellants used in MDIs are potent GHGs, up to 3350 times worse than carbon dioxide (CO2).⁴ According to UK data, one patient’s inhalers for one year (three salbutamol inhalers at 28 kg CO2 equivalent [CO2e] each and 12 controller inhalers at 19 kg CO2e each) are equivalent to driving a car 3200 km.⁴ These emissions are 10 to 37 times that of dry-powder inhalers (DPIs) and soft-mist inhalers (e.g., Respimat), which produce less than 1 kg CO2e/inhaler.⁵ Anesthetic gases most noteworthy for GHG emissions are desflurane, which is 2540 times more detrimental than CO2, and nitrous oxide, which is less damaging than desflurane but used in high volumes throughout health care.⁴ Sevoflurane is an alternative anesthetic gas that produces seven times less GHG emissions than desflurane. In addition, pharmaceuticals enter water systems through drug manufacturing effluent, human excretion and improper disposal and are subsequently ingested, leading to negative impacts on human health, human fetuses and wildlife.⁶ Reducing overall pharmaceutical usage (e.g., rationally prescribing, deprescribing, not stockpiling), choosing less carbon-intensive products (e.g., DPIs) and ensuring proper disposal through incineration can reduce the overall impact of pharmaceutical GHGs. The NHS is leading the way to environmental sustainability using initiatives related to energy, travel and procurement.⁷ Their carbon reduction strategy has contributed to a reduction of 19% in the health and social care carbon footprint between 2007 and 2017.⁷ Although individual organisations in Canada may be working toward a greener health care system, there is a paucity of literature indicating and supporting successful local initiatives. Proposed key actions for health care to support a healthy world include leadership committed to environmental health, immediately reducing GHG emissions and procuring sustainable products and materials, particularly pharmaceuticals.⁸ In addition, the WHO promotes cleaner energy systems, public transportation and active movement, such as cycling or walking in lieu of driving, as major means to reduce household and ambient air pollution.² Pharmacists are uniquely positioned and skilled as trusted health care professionals and clinical leaders to take a leadership role in the environmental movement. The large carbon footprint of pharmaceuticals speaks to the essential role of pharmacists. Below are actions pharmacists can implement to improve the health of the planet and patients:

1. Use DPIs or soft-mist inhalers in place of MDIs when clinically appropriate. The NHS has developed a patient decision aid for inhalers for asthma, which includes a carbon footprint consideration.⁹ In addition, pharmacists can educate patients on proper inhaler techniques to minimise wastage.⁴
2. Optimise medications, including promoting rational and stewardly prescribing.¹⁰ Optimisation of medications according to the National Institute for Health and Care Excellence guideline is estimated to save 202 tons of GHG emissions, primarily through the reduction of avoidable drug-related hospital admissions.¹¹
3. Promote less carbon-intensive inhaled anesthetics, such as sevoflurane in place of desflurane as clinically appropriate, and reduce the unnecessary use of nitrous oxide.⁴
4. Educate patients and colleagues on proper disposal of pharmaceuticals, including MDIs (i.e., return to the pharmacy for incineration).^6,10
5. Educate patients and other health care professionals on sustainable health care.¹²
6. Advocate to leadership, including health care leadership, politicians and professional organisations, to prioritise and develop an environmentally sustainable health care system.^3,13
7. Develop or join a local environmental committee. Online ideas and tools to support this initiative include Health Care without Harm (https://noharm.org/), Global Green and Healthy Hospitals (https://www.greenhospitals.net/), Safer Pharma (http://saferpharma.org/) and My Green Doctor (https://www.mygreendoctor.org/). Several health care organisations from across Canada are currently members of one or more of these green initiatives.
8. Review personal practices to identify individual opportunities, such as biking or walking to work, meeting with patients or colleagues digitally or minimising unnecessary paper usage and opting for electronic journal subscriptions.
9. Everyone has a responsibility in environmental sustainability, and pharmacists are particularly responsible for the sustainable use of pharmaceuticals. The urgency of climate change warrants immediate action from leadership, individuals and organisations. Despite a dire outlook with current practices, there are numerous opportunities to implement positive change for the future health of patients and communities.

References

1. World Health Organization. Urgent health challenges for the next decade. 2020. Available:https://www.who.int/news-room/photo-story/photo-story-detail/urgent-health-challenges-for-the-next-decade(accessed Jul. 22, 2020).
2. World Health Organization. Climate change and health. 2018. Available: https://www.who.int/news-room/fact-sheets/detail/climate-change-and-health(accessed Aug. 4, 2020).
3. Eckelman MJ, Sherman JD, MacNeill AJ. Life cycle environmental emissions and health damages from the Canadian health care system: an economic-environmental-epidemiological analysis. PLoS Med2018;15(7):e1002623. [PMC free article] [PubMed] [Google Scholar]
4. NHS Sustainable Development Unit. Anaesthetics and inhalers. 2020. Available from: https://www.sduhealth.org.uk/nhslongtermplan/carbon-reduction/anaesthetics-and-inhalers.aspx(accessed Aug. 5, 2020).
5. Wilkinson AJK, Braggins R, Steinbach I, Smith J. Costs of switching to low global warming potential inhalers: an economic and carbon footprint analysis of NHS prescription data in England. BMJ Open. 2019;9(10): e28763. [PMC free article] [PubMed] [Google Scholar]
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8. Health Care without Harm. Mission and goals. Available: https://noharm-uscanada.org/content/us-canada/mission-and-goals(accessed Aug. 9, 2020).
9. National Institute for Health and Care Excellence (NICE). Patient decision aid inhalers for asthma. 2019. Available: https://bit.ly/inhalervids(accessed Jul. 22, 2020).
10. Safer Pharma. Safer medicine for a safer world. Available: http://saferpharma.org/(accessed Aug. 5, 2020).
11. National Institute for Health and Care Excellence (NICE). Environmental impact report: medicines optimisation—implementing the NICE guideline on medicines optimisation (NG5). Available: https://www.nice.org.uk/Media/Default/About/what-we-do/Into-practice/resource-impact-assessment/Medicines-optimisation-sustainability-report.pdf(accessed Jul. 27, 2020).
12. Desmond S. Health service planning and sustainable development: considering what, where and how care is delivered through a pro-environmental lens. Aust Health Rev2017;42:140-5. [PubMed] [Google Scholar]
13. Health Care without Harm. Available: https://noharm.org/(accessed Jul. 20, 2020).

 

Menna Zayed is a clinical pharmacist, public health professional, and planetary health advocate dedicated to advancing climate justice, health equity, and sustainable healthcare systems. Her work lies at the intersection of health and the environment, with a strong focus on addressing systemic inequities and strengthening climate-resilient health systems. With experience spanning research, policy, advocacy, and community engagement, Menna has contributed to global health and sustainability initiatives through collaborations with organizations such as the International Pharmaceutical Federation (FIP), the World Health Organization, and Women in Global Health. She actively engages in global climate and health policy spaces, including participation in the United Nations Climate Change Conferences (COP27, COP28, and COP29), where she advocates for the integration of health into climate action and elevates the role of healthcare professionals in driving sustainability. Menna currently leads community-based environmental and public health projects in Egypt, working closely with communities to co-design and implement solutions that address the health impacts of climate change and waste pollution. Her work bridges local realities with global advocacy, ensuring that community voices are heard in decision-making processes. Menna is committed to building a just and sustainable future where health systems are both inclusive and environmentally responsive.