From hazardous waste to fuel: How clinics are reducing climate impact

A neat lawn and a set of colorful flower pots outside Kathmandu's Tribhuvan University Teaching Hospital in Nepal conceal an unpleasant underground secret. The idyllic setting is where hospital staff dump kitchen scraps and biohazardous, pathological waste. The bloody mixture decomposes to release methane — a harmful greenhouse gas. Hospital waste can cause serious risks in many low- and middle-income countries, where disposal methods vary and where resource constraints and lack of training can mean it is not dealt with safely. But at Tribhuvan, workers pour the waste into a hidden, custom-designed biodigester underground, instead of burning it or leaving it to rot at a public dump. And the gas released? That is safely piped to the staff tearoom, where it is used as cooking fuel. This low-tech solution is just one of the steps Nepal’s largest hospital has taken to mitigate the harmful impacts health care waste can have on the environment and human health. Health’s climate footprint Studies cited in a 2022 World Health Organization report on the effects of health care waste in the context of COVID-19 suggest the sector is responsible for 4-5% of total global greenhouse gas emissions. WHO estimates that 15% of health care waste is hazardous and may be infectious, toxic, or radioactive. Yet globally less than one-third of health facilities had a basic waste management service in 2019. And a similar proportion lacked systems to segregate waste. Mahesh Nakarmi, executive director of the Health, Environment and Climate Action Foundation of Nepal, or HECAF360, worked with Health Care Without Harm, or HCWH, a global NGO championing sustainable health care, to develop the digester used at Tribhuvan in 2017. “Pathological waste management is a very challenging task; it brings a very bad smell and is a high risk to public health,” Nakarmi told Devex. The 700-bed facility produces about a ton of waste a day. Prior to the digester, staff incinerated waste such as placentas. But as they are composed of about 60% water, workers added paper and plastics to fuel the fire, which caused air pollution. Workers also used to pile up hospital food waste outside the building before waste collectors took it to a municipal dump, which attracted rats and flies before collection, Nakarmi added. Designing solutions Nakarmi, an engineer by background, worked with a biodigester expert to create the digester. The simple technology is used widely on farms in Nepal. Hospital staff disposes of waste through two inlets above the ground, which fall into the first of two chambers, where it mixes with cow dung to aid the process and water to keep it flowing. The placentas are potentially infectious, but take about six months to decompose, by which time any dangerous pathogens are eliminated. The “digest” — or waste — flows into a sewer connected to the tank. “There are no mechanical issues,” Nakarmi said. Gravity moves the mixture along. The digester uses no power and is low-maintenance. The hospital funded the project at a cost of about $25,000. “For the biggest teaching hospital in the country, that’s not a huge amount of money,” says HCWH International Science and Policy Coordinator Ruth Stringer. An added side benefit to the project is the methane gas it generates, which is worth about $20 in savings for every ton of waste disposed of. Overlooked issue Today, five hospitals in Nepal have waste biodigesters. HCWH also installed digesters at hospitals in Tanzania and Madagascar between 2016 and 2020 as part of a United Nations Development Programme initiative to reduce unintentional persistent organic pollutants and mercury releases from the health sector in Africa. The governments in both countries were so pleased with the results, they built digesters in other health facilities, Stringer added. But despite the approach’s positive results, very few health care settings have the system in place. Stringer says this is partly due to a lack of space, particularly at hospitals in urban locations. But there is a bigger problem of general poor understanding of health care waste management. Nakarmi believes this is caused by the multidisciplinary nature of the issue. “It can only be solved by a multispecialty team of engineers, public health workers, doctors, nurses, environmentalists, and so on when they come together,” he says. Stringer points out that awareness about alternative, green waste treatment options is also low because little funding is available for waste in the health sector. Even COVID-19 which brought medical waste management into sharp relief with the sudden increased use of masks and syringes has not led to change. “Health care is under pressure globally — the needs are always greater than the resources available,” says Stringer. Greener hospitals Health systems everywhere have the potential to adapt to the risks posed by climate change and promote sustainability, greater health equity, and environmental health, according to one health-strengthening agenda. The Global Green and Healthy Hospitals, or GGHH, network, an HCWH project, has helped spur transformative action by supporting over 1,700 members in more than 80 countries to implement sustainable health care approaches. It advocates hospitals invest in greener buildings, procure resources that are less damaging, and implement sustainable operations. Changing climates are already prompting health providers to rethink their operations. An extreme drought in South Africa in 2016 convinced the Western Cape Government Department of Health to add a water harvesting facility to the roof of a new clinic it was constructing. The District Six Clinic in Cape Town is a four-story building, which can store water in a harvesting reservoir in its basement, collecting roughly 175,000 liters of water a year. Over a four-month period of studying its efficiency in 2018, the health department’s Facilities and Infrastructure Management Commissioning Manager Thorpe Koorts found the system was providing 21% of the clinic’s total water consumption. “The rainwater is being used for flushing toilets, cleaning floors, and maybe cleaning things outside, like ambulances, or watering the garden,” Koorts said. The water has to be stored underground to avoid it creating other potential health hazards, such as attracting mosquitoes, he added. It also passes through filters as it flows down pipes off the roof. “It needs minimal maintenance,” Koorts said. But the hospital cannot rely on rainwater alone. It has two water systems, as consulting rooms must have access to potable, municipality-provided water. This means that the cost of building the rain harvester didn’t bring a return on investment. Koorts estimates it would take “hundreds of years” to earn back the money, compared to the cost of using municipal water, but adds that from a need perspective, the cost is irrelevant. “We almost ran out of water,” he said, referring to the droughts. “[We must] build up resilience and still be able to run services when things go very horribly wrong in nature. From that perspective, it's a no-brainer.” Systemic change Despite efforts from health care providers to operate in more environmentally friendly ways, the sector cannot solve the problem alone. A study by researchers at the University of Sydney published in 2022 suggests the negative environmental impacts of health care on the environment cannot be separated from the harmful effects of its supply chains. “Direct measures to reduce impacts in the health sector certainly have a role to play, however, we need to consider the supply chain impacts as well,” says Arunima Malik, one of the researchers and an associate professor in sustainability at the University of Sydney. The study shows supply chain impacts are substantial, as demand for goods and services by the health sector — such as electricity, medical equipment, and pharmaceuticals — contribute to greenhouse gas emissions, air pollution, and scarce water impacts. “There is a need for a broad sector-wide engagement for addressing impacts associated with health and other economic sectors,” says Malik. As GGHH warns, the Hippocratic oath of “First Do No Harm” needs to move beyond the immediacy of the doctor-patient relationship, to incorporate a more global vision of health and sustainability. Visit the Planet Health series for more in-depth reporting on the current impact of the climate crisis on human health around the world. Join the conversation by using the hashtag #PlanetHealth.