Anoushka Krishnan, MD
Department of Nephrology, Royal Perth Hospital, Perth, Australia
“The truth is that climate change is presenting the greatest challenge humanity has ever faced”- Al Gore
Climate change is rapidly making its presence felt across the globe. We have all seen the recent destruction left in its wake with the droughts in Europe, the floods in Asia and the fires in Australia- and this is only the beginning. Human activity is taking a significant toll on our environment as evidenced by rising sea levels, shrinking ice masses, rising global temperatures, and mounting atmospheric carbon dioxide levels. So why should we, as health care professionals, worry about this? Well, that’s because climate change is touted to be the biggest global health threat of the 21st century.
Climate change is already undermining many of the social and environmental determinants of health and impacting on livelihoods, equitable access to health care, and affecting basic human needs like clean air, potable water and secure shelter. It is estimated that by 2050, there will be an additional 250,000 deaths attributed to heat stress, malaria and diarrhea. And this comes at a very hefty price tag, with direct costs to health estimated to be around 2 billion USD. Unfortunately, developing countries and vulnerable segments of society (women, children, elderly persons, lower socioeconomic individuals, refugees, ethnic minorities and those with chronic medical conditions) are more likely to be impacted in the most severe manner.
You may wonder about the impact of climate change on kidney health. As nephrologists, this is certainly something that should concern us.
- Studies have shown that periods of heat waves are associated with an excess risk of acute kidney injury (AKI) from heat stress and consequently a higher rate of hospitalization and death. Dehydration, decreased kidney perfusion and renal vaso-constriction are the likely pathogenic mechanisms leading to AKI. Vulnerable populations include people at the extremes of age, those with underlying chronic kidney disease (CKD) and those on medications such as diuretics or renin-angiotensin-aldosterone (RAAS) blockade which impede the ability to auto-regulate risk factors that we are already quite familiar with.
- The risk of AKI can also be increased from a rise in vector-borne diseases like malaria and dengue. There is the additional concern of an increased risk of CKD.
- There has been a ‘CKD epidemic’ in young workers across the equatorial belt in developing nations, who work outdoors in the heat for long hours. Sometimes called CKD of unclear etiology (CKDu), these individuals can present with deranged kidney function with minimal proteinuria. Kidney biopsy typically demonstrates tubulo-interstitial damage, likely at least partially related to chronic heat stress. Given the paucity of access to kidney replacement therapies (KRT) in these geographical regions, death rates can often be high.
Clearly, there is a substantial impact of climate change on kidney health, but conversely, can health care and kidney care contribute to climate change? The answer is a resounding and unfortunate yes. In fact, if health care was a country, it would be the 5th largest greenhouse gas emitter in the world, with a large portion contributed by healthcare supply chains. KRT, in particular dialysis, is resource intensive, and given the frequency of administration of treatment, the per capita resource consumption is probably the highest in healthcare.
Have you ever wondered how power or water hungry our dialysis machines are? Each four-hour haemodialysis (HD) session consumes up to 600 liters of water. Most reverse osmosis (RO) filters will discard up to two-thirds of purified water down the drains. Millions of liters of water can be wasted per annum in this manner. Dialysis units also utilize a lot of power for the functioning of the ROs. Each HD session can generate up to 7-8 kg of waste per patient including dialyzers and tubing. While general waste goes to landfill and can contaminate soil and drinking water, clinical waste is often incinerated, releasing pollutants and ash residue into the air that can have a range of adverse effects on human health and are toxic to the environment. The carbon footprint of HD is large, up to 10.2 tonne CO2 equivalent per patient per annum (each HD session is almost the equivalent of driving your car for 250 km or 155 miles). While peritoneal dialysis (PD) may seem less resource intensive, it is likely to have a large environmental footprint too, particularly as it is a daily therapy. PD also generates a lot of plastic waste and can have a high carbon footprint from the need to deliver PD bags and transfer waste products. As inflation worsens, cost of utilities rise and patient numbers burgeon, we will come to a point where dialysis will not be sustainable anymore! While we don’t have much published data on the impact of kidney transplantation, it is likely that the environmental impact, though high in the first year, is likely to reduce in the long term (by negating the need for energy/ water consumption and generation of large volumes of waste compared to dialysis). Therefore, increasing rates of transplantation may be one way to combat this grim scenario.
Hopefully, this has now convinced you that there is a clear bidirectional impact of kidney health and kidney care on climate change. And that kidney care comes with a high financial and environmental cost. Moreover, the number of people with CKD is only increasing. Therefore, improvements in this sphere should be considered as essential business and we as nephrologists should be the flag bearers for this cause.
So, is this all doom and gloom then? No- it doesn’t have to be this way. There are many measures that we can take within our units to try and reduce the impact of kidney care on the environment. Of course, slowing the progression of kidney disease (by recognizing kidney disease early, managing risk factors and instituting appropriate therapies) and improving access to kidney transplantation play defining roles in reducing impact. Additionally, building modern purpose-built dialysis units to reduce impact and meet demand is now a necessity, no longer just a luxury option. Installation of solar panels, improved segregation of waste, implementing better methods to dispose of waste locally, repurposing medical plastic (e.g. using this to resurface concrete) and re-routing ‘rejected’ but purified RO water for purposes like cleaning, hydroponics, aquaculture, feeding livestock, etc are just a few ways in which a modern dialysis unit can aim to reduce its footprint.
What can you do locally though? Have you thought about auditing the resources used and waste generated at your local HD unit? Without knowing how much we consume; it is impossible to understand how we can improve. For example, several dialysis centers in Europe audited their energy and water consumption over a decade ago. This then allowed them to develop action plans and work together to upgrade their HD machines to more efficient versions.
Have you thought about delivering a talk on this topic to your department? People are often not aware of the impacts of kidney care and improving awareness amongst medical and nursing staff is a pivotal step to making change. Simple things like increasing telehealth services, using electronic communication where possible, paperless reporting of results, and improving local recycling practices are all small steps towards change. You could also consider conducting a ‘green’ research project on your unit.
Key nephrology societies around the world (including in the UK, Canada and Australia) are advocating for change and several countries (such as Brazil, Japan and Italy) have put out statements calling for action. There is also a big role here for collaboration between medical staff, consumers, industry and other disciplines (like engineering or architecture) to focus on research and development to improve infrastructure and efficiency of machines.
We need to re-direct our efforts, not just towards improving patient outcomes but also doing this in a sustainable manner that minimizes our footprint on this already troubled planet. The time.. is now!
Conflicts of interest: None
Acknowledgements: Dr Katherine Barraclough, Chair of the Environmental Sustainability Committee, Australia and New Zealand Society of Nephrology
Reviewed by Amy Yau and Matthew A. Sparks