Waste from health-care activities
- Of the total amount of waste generated by health-care activities, about 80% is general waste.
- The remaining 20% is considered hazardous material that may be infectious, toxic or radioactive.
- Every year an estimated 16 000 million injections are administered worldwide, but not all of the needles and syringes are properly disposed of afterwards.
- Health-care waste contains potentially harmful microorganisms which can infect hospital patients, health-care workers and the general public.
Health-care activities, protect and restore health and save lives. But what about the wastes and by-products they generate?
Of the total amount of waste generated by health-care activities, about 80% is general waste comparable to domestic waste. The remaining 20% is considered hazardous material that may be infectious, toxic or radioactive.
Types of waste
Waste and by-products cover a diverse range of materials, as the following list illustrates (percentages are approximate values):
- infectious waste: waste contaminated with blood and its by-products, cultures and stocks of infectious agents, waste from patients in isolation wards, discarded diagnostic samples containing blood and body fluids, infected animals from laboratories, and contaminated materials (swabs, bandages) and equipment (such as disposable medical devices);
- pathological waste: recognizable body parts and contaminated animal carcasses;
- sharps: syringes, needles, disposable scalpels and blades, etc.;
- chemicals: for example mercury, solvents and disinfectants;
- pharmaceuticals: expired, unused, and contaminated drugs; vaccines and sera;
- genotoxic waste: highly hazardous, mutagenic, teratogenic1 or carcinogenic, such as cytotoxic drugs used in cancer treatment and their metabolites;
- radioactive waste: such as glassware contaminated with radioactive diagnostic material or radiotherapeutic materials;
- heavy metals waste: such as broken mercury thermometers.
Infectious and anatomic wastes together represent the majority of the hazardous waste, up to 15% of the total waste from health-care activities. Sharps represent about 1% of the total waste but they are a major source of disease transmission if not properly managed. Chemicals and pharmaceuticals account for about 3% of waste from health-care activities while genotoxic waste, radioactive matter and heavy metal content account for around 1% of the total health-care waste.
The major sources of health-care waste are:
- hospitals and other health-care establishments
- 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 bed per day; while low-income countries generate on average 0.2 kg of hazardous waste per hospital bed per day. However, health-care 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-care waste contains potentially harmful micro-organisms which can infect hospital patients, health-care workers and the general public. Other potential infectious risks may include the spread of drug-resistant micro-organisms from health-care establishments into the environment.
Waste and by-products can also cause injuries, for example:
- radiation burns;
- sharps-inflicted injuries;
- poisoning and pollution through the release of pharmaceutical products, in particular, antibiotics and cytotoxic drugs;
- poisoning and pollution through waste water; and
- poisoning and pollution by toxic elements or compounds, such as mercury or dioxins that are released during incineration.
Throughout the world an estimated 16 000 million injections are administered every year. Not all needles and syringes are properly disposed of, creating a risk of injury and infection and opportunities for re-use.
- WHO estimates that, in 2000, injections with contaminated syringes caused 21 million hepatitis B virus (HBV) infections, two million hepatitis C virus infections and 260 000 HIV infections worldwide. Many of these infections were avoidable if the syringes had been disposed of safely. The re-use of disposable syringes and needles for injections is particularly common in certain African, Asian and Central and Eastern European countries.
- In developing countries, additional hazards occur from scavenging at waste disposal sites and the manual sorting of hazardous waste from health-care establishments. These practices are common in many regions of the world. The waste handlers are at immediate risk of needle-stick injuries and exposure to toxic or infectious materials.
In June 2000 six children were diagnosed with a mild form of smallpox (vaccinia virus) after having played with glass ampoules containing expired smallpox vaccine at a garbage dump in Vladivostok (Russia). Although the infections were not life-threatening, the vaccine ampoules should have been treated before being discarded.
The use of radiation sources in medical and other applications is widespread throughout the world. Occasionally, the public is exposed to radioactive waste, which originates from radiotherapy treatment, that has not been disposed of properly. Serious accidents have been documented in Brazil in 1988 (where four people died and 28 had serious radiation burns), Mexico and Morocco in 1983, Algeria in 1978 and Mexico in 1962.
Risks associated with other types of health-care waste, in particular blood waste and chemicals, may be significant but have not been fully assessed. More work needs to be done. In the meantime, precautionary measures should be taken.
Risks associated with waste disposal
Although treatment and disposal of health-care waste reduces risks, indirect health risks may occur through the release of toxic pollutants into the environment through treatment or disposal.
- Landfills can contaminate drinking-water if they not properly constructed. Occupational risks exist at disposal facilities that are not well designed, run, or maintained.
- Incineration of waste has been widely practised but inadequate incineration or the incineration of unsuitable materials results in the release of pollutants into the air and of ash residue. Incinerated materials containing chlorine can generate dioxins and furans2, 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. Dioxins, furans and metals are persistent and bio-accumulate in the environment. Materials containing chlorine or metal should therefore not be incinerated.
- 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 are now available, such as autoclaving, microwaving, steam treatment integrated with internal mixing, and chemical treatment.
Waste management: reasons for failure
Lack of awareness about the health hazards related to health-care waste, inadequate training in proper waste management, absence of waste management and disposal systems, insufficient financial and human resources and the low priority given to the topic are the most common problems connected with health-care waste. Many countries either do not have appropriate regulations, or do not enforce them. An essential issue is the clear attribution of responsibility for the handling and disposal of waste. According to the 'polluter pays' principle, the responsibility lies with the waste producer, usually the health-care provider, or the establishment involved in related activities. To achieve the safe and sustainable management of health-care waste, financial analyses should include all the costs of disposal.
Steps towards improvement
Improvements in health-care waste management rely on the following key elements:
- 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 health-care waste, and of safe and sound practices;
- 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.
The first global and comprehensive guidance document, Safe management of wastes from health-care activities, originally released by WHO in 19993, addresses aspects such as regulatory framework, planning issues, waste minimization and recycling, handling, storage and transportation, treatment and disposal options, and training.
It is aimed at managers of hospitals and other health-care establishments, policy makers, public health professionals and managers involved in waste management. It is accompanied by a Teacher's guide, which contains material for a three-day workshop aimed at the same audience.
Additionally, WHO guidance documents on health-care waste are now available including:
- a monitoring tool
- a cost assessment tool
- a rapid assessment tool
- a policy paper
- guidance to develop national plans
- management of waste from injection activities
- management of waste at primary health care centres
- management of waste from mass immunization activities
- management of waste in emergencies.
The full text of these publications is available on the WHO water, sanitation and health web site.
1Teratogenic: capable of producing fetal malformation.
2Furans: group of heterocyclic compounds similar to dioxins.
3Second edition - 2012