Environmental accountability in perioperative settings

AORN Journal,  June, 2003  by Ann Melamed

• E-mail
• Print
• Link

INFECTIOUS WASTE TREATMENT

Infectious waste must be treated before disposal in a municipal landfill. Treatment can be accomplished on- or off-site. Treatment modalities include three basic processes: heat (ie, sterilizing, microwaving, incineration, pyrolysis), chemical treatment (ie, hypochlorite, chlorine dioxide), and radiation treatment.

Medical waste incineration creates many toxic by-products, is a serious contributor to pollution, and has been identified by the EPA as a leading source of dioxins and anthropogenic mercury in the environment. (22) Some states still require incineration of certain portions of the infectious waste stream (eg, pathology waste, including body parts). (23) In general, however, incineration of waste is an outdated technology and one that the health care industry must stop using because even the most advanced incinerators continue to produce and release dioxins and other serious, persistent pollutants.

Dioxins. Dioxins are a group of chemicals that are toxic by-products of industrial processes. They enter the air as waste from combustion. Some of the major sources of dioxins in the environment are the manufacture of chlorinated chemicals; bleaching of paper products; and incineration of medical, municipal, and hazardous wastes. (24)

Dioxins are a known human carcinogen. Other health effects associated with dioxins include changes in hormone systems, alterations in fetal development, infertility, endometriosis, immune suppression, and chloracne. Every person ever tested has a body burden of dioxins. It is a persistent and bioaccumulative toxin with a half-life in decades. Bioaccumulation refers to the tendency of a pollutant to magnify as it moves up the food chain. Humans get their major exposure to dioxins through fatty food, especially animal products, because dioxins, like many other toxins, are lipophilic. A nursing infant receives some of its highest lifetime doses of dioxins when nursing. (25) Although authorities agree that breast-feeding still is the preferable feeding method for infants because of the many other benefits, all nurses should know that keeping these serious toxins out of infants' milk supply is a global patient care issue. Alternatives to medical waste incineration are preferable because the toxic by-products emitted from incinerators are transported into the global environment and enter the food chain everywhere.

Alternatives to incineration. Many incinerators have closed down because of their inability to comply with stricter regulations. Alternative treatment technologies are developing rapidly, but at present, they must be approved state by state. In any waste treatment technology, segregation is a key issue. Hazardous wastes must be segregated and disposed of according to state hazardous waste regulations, or the air, land, and water will become contaminated. Careful segregation at the source of generation is essential, regardless of the waste stream or its ultimate disposal.

Many hospitals and health care systems use autoclaves to treat most types of infectious waste to render them suitable for a sanitary landfill. Waste treatment autoclaves work in much the same way as they do in a perioperative setting, and there are prevacuum and gravity displacement types. After the waste is loaded into the chamber, the prevacuum autoclave, which is more efficient but often more Costly, (26) vacuums out the air so that high pressure and temperature are achieved faster. Gravity displacement works on the principle that steam, being lighter than air in the autoclave, will displace the air downward and allow the steam and heat to reach optimum temperature and pressure. After treatment, the waste is rendered noninfectious and can be sent to a sanitary landfill. Many autoclave technology systems also shred or compact the waste before it is sent to a landfill. (27) Figure 3 shows a hospital medical waste autoclave. Smaller models serve individual hospitals. The types of waste that can be treated in a autoclave include