Health-care activities for instance, immunizations, diagnostictests, medical treatments, and laboratory examinations - protect andrestore health and save lives. But what about the wastes andby-products they generate?From the total of wastes generated by health-care activities, almost80% are general waste comparable to domestic waste. The remainingapproximate 20% of wastes are considered hazardous materials that maybe infectious, toxic or radioactive. The wastes and by-products covera diverse range of materials, as the following list illustrates(percentages are approximate values): * Infectious wastes -- cultures and stocks of infectious agents,wastes from infected patients, wastes contaminated with blood and itsderivatives, discarded diagnostic samples, infected animals fromlaboratories, and contaminated materials (swabs, bandages) andequipment (disposable medical devices etc.); and * Anatomic - recognizable body parts and animal carcasses.Infectious and anatomic wastes together represent the majority of thehazardous waste, up to 15% of the total waste from health-careactivities. * Sharps -- syringes, disposable scalpels and blades etc.Sharps represent about 1% of the total waste from health-care activities. * Chemicals -- for example solvents and disinfectants; and * Pharmaceuticals -- expired, unused, and contaminated; whetherthe drugs themselves (sometimes toxic and powerful chemicals) or theirmetabolites, vaccines and sera .Chemicals and pharmaceuticals amount to about 3% of waste fromhealth-care activities. * Genotoxic waste -- highly hazardous, mutagenic, teratogenic1 orcarcinogenic, such as cytotoxic drugs used in cancer treatment andtheir metabolites; and * Radioactive matter, such as glassware contaminated withradioactive diagnostic material or radiotherapeutic materials; * Wastes with high heavy metal content, such as broken mercury thermometers.Genotoxic waste, radioactive matter and heavy metal content representabout 1% of the total waste from health-care activities.The major sources of health-care waste are hospitals and otherhealth-care establishments, laboratories and research centres,mortuary and autopsy centres, animal research and testinglaboratories, blood banks and collection services, and nursing homesfor the elderly.High-income countries can generate up to 6 kg of hazardous waste perperson per year. In the majority of low-income countries, health-carewaste is usually not separated into hazardous or non-hazardous waste.In these countries, the total health-care waste per person per year isanywhere from 0.5 to 3 kg.Health impactsHealth-care waste is a reservoir of potentially harmfulmicro-organisms which can infect hospital patients, health-careworkers and the general public. Other potential infectious risksinclude the spread of, sometimes resistant, micro-organisms fromhealth-care establishments into the environment. These risks have sofar been only poorly investigated. Wastes and by-products can alsocause injuries, for example radiation burns or sharps-inflictedinjuries; poisoning and pollution, whether through the release ofpharmaceutical products, in particular, antibiotics and cytotoxicdrugs, through the waste water or by toxic elements or compounds suchas mercury or dioxins.SharpsThroughout the world every year an estimated 12 000 million injectionsare administered. And not all needles and syringes are properlydisposed of, generating a considerable risk for injury and infectionand opportunities for re-use. * Worldwide, 8-16 million hepatitis B, 2.3 to 4.7 millionhepatitis C and 80 000 to 160 000 HIV infections are estimated tooccur yearly from re-use of syringe needles without sterilization2.Many of these infections could be avoided if syringes were disposed ofsafely. The re-use of disposable syringes and needles for injectionsis particularly common in certain African, Asian and Central andEastern European countries. * Regarding injection practices, public health authorities in WestBengal, India, have recommended a shift to re-usable glass syringes,as the disposal requirements for disposable syringes could not beenforced. * In developing countries, additional hazards occur fromscavenging on waste disposal sites and manual sorting of the wasterecuperated at the back doors of health-care establishments. Thesepractices are common in many regions of the world. The waste handlersare at immediate risk of needle-stick injuries and other exposures totoxic or infectious materials.Vaccine wasteIn June 2000, six children were diagnosed with a mild form of smallpox(vaccinia virus) after having played with glass ampoules containingexpired smallpox vaccine at a garbage dump in Vladivostok (Russia).Although the infections were not life-threatening, the vaccineampoules should have been treated before being discarded.Radioactive wastesThe use of radiation sources in medical and other applications iswidespread throughout the world. Occasionally, the public is exposedto radioactive waste, usually originating from radiotherapytreatments, that has not been properly disposed of. Serious accidentshave been documented in Goiânia, Brazil in 1988 in which four peopledied from acute radiation syndrome and 28 suffered serious radiationburns. Similar accidents happened in Mexico City in 1962, Algeria in1978, Morocco in 1983 and Ciudad Juárez in Mexico in 1983.Risks associated with other fractions of health-care wastes, inparticular blood waste and chemicals, have been relatively poorlyassessed, and need to be strengthened. In the meantime, precautionarymeasures need to be taken.Risks associated with waste disposalAlthough treatment and disposal of health-care wastes aim at reducingrisks, indirect health risks may occur through the release of toxicpollutants into the environment through treatment or disposal. * Landfilling can potentially result in contamination of drinkingwater. Occupational risks may be associated with the operation ofcertain disposal facilities. Inadequate incineration, or incinerationof materials unsuitable for incineration can result in the release ofpollutants into the air. The incineration of materials containingchlorine can generate dioxins and furans3, which are classified aspossible human carcinogens and have been associated with a range ofadverse effects. Incineration of heavy metals or materials with highmetal contents (in particular lead, mercury and cadmium) can lead tothe spread of heavy metals in the environment. Dioxins, furans andmetals are persistent and accumulate in the environment. Materialscontaining chlorine or metal should therefore not be incinerated. * Only modern incinerators are able to work at 800-1000 °C, withspecial emission-cleaning equipment, can ensure that no dioxins andfurans (or only insignificant amounts) are produced. Smaller devicesbuilt with local materials and capable of operating at these hightemperatures are currently being field-tested and implemented in anumber of countries. * At present, there are practically no environmentally-friendly,low-cost options for safe disposal of infectious wastes. Incinerationof wastes has been widely practised, but alternatives are becomingavailable, such as autoclaving, chemical treatment and microwaving,and may be preferable under certain circumstances. Landfilling mayalso be a viable solution for parts of the waste stream if practisedsafely. However, action is necessary to prevent the important diseaseburden currently created by these wastes.In addition, perceived risks related to health-care waste managementmay be significant. In most cultures, disposal of health-care wastesis a sensitive issue and also has ethical dimensions.Waste management -- reasons for failureThe absence of waste management, lack of awareness about the healthhazards, insufficient financial and human resources and poor controlof waste disposal are the most common problems connected withhealth-care wastes. Many countries do not have appropriateregulations, or do not enforce them. An essential issue is the clearattribution of responsibility of appropriate handling and disposal ofwaste. According to the 'polluter pays' principle, this responsibilitylies with the waste producer, usually being the health-care provider,or the establishment involved in related activities.Steps towards improvementImprovements in health-care waste management rely on the following key elements: * The build-up of a comprehensive system, addressingresponsibilities, resource allocation, handling and disposal. This isa long-term process, sustained by gradual improvements; * Awareness raising and training about risks related tohealth-care waste, and safe and sound practices; * Selection of safe and environmentally-friendly managementoptions, to protect people from hazards when collecting, handling,storing, transporting, treating or disposing of waste.Government commitment and support is needed to reach an overall andlong-term improvement of the situation, although immediate action canbe taken locally.Health-care waste management is an integral part of health-care, andcreating harm through inadequate waste management reduces the overallbenefits of health-care.