Key facts
- Of the total amount of waste generated by healthcare activities, about 85% is general, non-hazardous waste.
- The remaining 15% is considered hazardous material that may be infectious, toxic, carcinogen, flammable, corrosive, reactive, explosive or radioactive.
- Every year an estimated 16 billion injections are administered worldwide, but not all the needles and syringes are properly disposed of afterwards.
- Open burning and low-temperature incineration of health care wastes can, under some circumstances, result in the emission of dioxins, furans and particulate matter.
Overview
Healthcare activities protect and restore health and save lives. But what about the waste and by-products they generate?
Of the total amount of waste generated by healthcare activities, about 85% is general, non-hazardous waste comparable to domestic waste. The remaining 15% is considered hazardous material that may be infectious, chemical or radioactive.
Measures to ensure the safe and environmentally sound management of health care wastes can prevent adverse health and environmental impacts from such waste including the unintended release of chemical or biological hazards.
Types of waste
Waste and by-products cover a diverse range of materials, including:
- infectious waste: waste known or suspected to contain pathogens and pose a risk of disease transmission, e.g. waste and waste water contaminated with blood and other body fluids, including highly infectious waste such as laboratory cultures and microbiological stocks; and waste including excreta and other materials that have been in contact with patients infected with highly infectious diseases in isolation wards;
- pathological waste: human tissues, organs or fluids, body parts, foetuses, unused blood products and contaminated animal carcasses;
- sharps waste: used or unused sharps, e.g. hypodermic, intravenous or other needles; auto-disable syringes; syringes with attached needles; infusion sets; scalpels; pipettes; knives; blades; broken glass;
- chemical waste: for example, solvents and reagents used for laboratory preparations, disinfectants, sterilants and heavy metals contained in medical devices (e.g. mercury in broken thermometers) and batteries;
- pharmaceutical and cytotoxic waste: pharmaceuticals that are expired or no longer needed; items contaminated by, or containing, pharmaceuticals. Cytotoxic waste containing substances with genotoxic properties, e.g. waste containing cytostatic drugs (often used in cancer therapy); genotoxic chemicals;
- radioactive waste: such as products contaminated by radionuclides including radioactive diagnostic material or radiotherapeutic materials; and
- non-hazardous or general waste: waste that does not pose any particular biological, chemical, radioactive or physical hazard.
The major sources of healthcare waste are:
- hospitals and other health facilities
- laboratories and research centres
- mortuary and autopsy centres
- animal research and testing laboratories
- blood banks and collection services
- nursing homes for the elderly.
High-income countries generate on average up to 0.5 kg of hazardous waste per hospital bed per day, while low-income countries generate on average 0.2 kg. However, healthcare waste is often not separated into hazardous or non-hazardous wastes in low-income countries making the real quantity of hazardous waste much higher.
Health risks
Healthcare waste contains potentially harmful microorganisms that can infect hospital patients, health workers and the public. Other potential hazards may include drug-resistant microorganisms which spread from health facilities into the environment.
Adverse health outcomes associated with health care waste and by-products also include:
- sharps-inflicted injuries;
- toxic exposure to pharmaceutical products, in particular, antibiotics and cytotoxic drugs released into the surrounding environment, and to substances such as mercury or dioxins, during the handling or incineration of health care wastes;
- chemical burns arising in the context of disinfection, sterilization or waste treatment activities;
- air pollution arising as a result of the release of particulate matter during medical waste incineration;
- thermal injuries occurring in conjunction with open burning and the operation of medical waste incinerators;
- radiation burns; and
- spread of antimicrobial resistance through unsafe storage, treatment and disposal of pharmaceutical waste.
Sharps-related
Worldwide, an estimated 16 billion injections are administered every year. Not all needles and syringes are disposed of safely, creating a risk of injury and infection and opportunities for reuse.
Injections with contaminated needles and syringes in low- and middle-income countries have reduced substantially in recent years, partly due to efforts to reduce reuse of injection devices. Despite this progress, in 2010, unsafe injections were still responsible for as many as 33 800 new HIV infections, 1.7 million hepatitis B infections and 315 000 hepatitis C infections (1).
A person who experiences one needle stick injury from a needle used on an infected source patient has risks of 30%, 1.8%, and 0.3% respectively of becoming infected with HBV, HCV and HIV.
Additional hazards occur from scavenging at waste disposal sites and during the handling and manual sorting of hazardous waste from healthcare facilities. These practices are common in many regions of the world, especially in low- and middle-income countries. The waste handlers are at immediate risk of needle-stick injuries and exposure to toxic or infectious materials.
According to WHO/UNICEF, in 2021, only 61% of hospitals had basic health-care waste services. The situation is far worse in fragile contexts, where based on 2023 data, only 25% of health facilities had basic health care waste management services (2).
Environmental and climate impact
Treatment and disposal of healthcare waste may pose health risks indirectly through the release of pathogens and toxic pollutants into the environment.
- The disposal of untreated health care wastes in landfills can lead to the contamination of drinking, surface, and ground waters if those landfills are not properly constructed.
- Minimization of health care waste should be a priority. This will significantly reduce the amount of waste that needs to be handled and treated. Waste minimization actions include green procurement and selecting products where shipping is minimized and with less and ecological packaging, switching to re-usables when safe and viable, only ordering/receiving pharmaceuticals based on documented need, and recycling common items including plastic, paper and cardboard.
- The treatment of health care wastes with chemical disinfectants can result in the release of chemical substances into the environment if those substances are not handled, stored and disposed in an environmentally sound manner.
- Incineration of waste is widely practised, but inadequate incineration or the incineration of unsuitable materials results in the release of pollutants into the air and in the generation of ash residue. Incinerated materials containing or treated with chlorine can generate dioxins and furans, which are human carcinogens and have been associated with a range of adverse health effects. Incineration of heavy metals or materials with high metal content (in particular lead, mercury and cadmium) can lead to the spread of toxic metals in the environment.
- Only modern incinerators operating at 850–1100 °C and fitted with special gas-cleaning equipment are able to comply with the international emission standards for dioxins and furans.
- Alternatives to incineration such as autoclaving, microwaving, steam treatment integrated with internal mixing, which minimize the formation and release of chemicals or hazardous emissions should be given consideration in settings where there are sufficient resources to operate and maintain such systems and dispose of the treated waste.
Waste management: reasons for failure
Several reasons exist for inadequate health care waste services. These include limited legal frameworks (e.g. policies, regulation, guidelines), lack of awareness about the health hazards related to healthcare waste, inadequate training in proper waste management, absence of waste management and disposal systems, insufficient financial and human resources and the low priority. Many countries either do not have appropriate regulations, or do not monitor and enforce them.
The way forward
The management of healthcare waste requires increased attention and diligence to avoid adverse health outcomes associated with poor practice, including exposure to infectious agents and toxic substances.
Key elements in improving healthcare waste management are:
- promoting practices that reduce the volume of wastes generated and ensure proposer waste segregation;
- developing strategies and systems along with strong oversight and regulation to incrementally improve waste segregation, destruction and disposal practices with the ultimate aim of meeting national and international standards;
- where feasible, favouring the safe and environmentally sound treatment of hazardous health care wastes (e.g. by autoclaving, microwaving, steam treatment integrated with internal mixing, and chemical treatment) over medical waste incineration;
- building a comprehensive system, addressing responsibilities, resource allocation, handling and disposal. This is a long-term process, sustained by gradual improvements;
- raising awareness of the risks related to healthcare waste, and of safe practices; and
- selecting safe and environmentally friendly management options, to protect people from hazards when collecting, handling, storing, transporting, treating or disposing of waste.
Government commitment and support is needed for universal, long-term improvement, although immediate action can be taken locally.
WHO response
WHO developed the first global and comprehensive guidance document, Safe management of wastes from healthcare activities, now in its second edition and more recently a short guide that summarizes the key elements as well as guidance on selecting technologies
The guide addresses the regulatory framework, planning, waste minimization and recycling, handling, storage and transportation, treatment and disposal options, and training. The document is aimed at healthcare facility managers, policy makers, public health professionals and waste experts. In addition, as part of monitoring Sustainable Development Goal 6 on safely managed water and sanitation, the WHO/UNICEF Joint Monitoring Programme regularly publishes data and reports on safe management of health care waste in health care facilities.
Finally, WHO, UNICEF and partners are working to strengthen safe and sustainable health care waste practices through wider efforts focused on WASH, waste and electricity in health care facilities.
This work is closely linked to the work on climate resilient and environmentally sustainable health systems for which health care waste is a critical element. In particular WHO guidance on climate resilient and environmentally sustainable health care facilities provides technical recommendations on how to improve the environmentally sustainability of waste management systems while safeguarding human health.
(1) Pépin J, Abou Chakra CN, Pépin E, Nault V, Valiquette L. Evolution of the global burden of viral infections from unsafe medical injections, 2000-2010.PLoSOne. 2014 Jun 9;9(6):e99677.
(2) WHO/UNICEF, 2024. Data update on WASH in health care facilities for 2023. World Health Organization, Geneva. https://washdata.org/reports