Medical waste management in Korea *

Transcription

1 Journal of Environmental Management xx (2005) Medical waste management in Korea * Yong-Chul Jang a, *, Cargro Lee a, Oh-Sub Yoon b, Hwidong Kim c a Department of Environmental Engineering, Chungnam National University, Daejeon , South Korea b Department of Environmental Engineering. Hanbat National University, Daejeon , South Korea c Department of Environmental Engineering Sciences, University of Florida, Gainesville, FL 32603, USA Received 7 December 2004; received in revised form 7 June 2005; accepted 18 August 2005 Abstract The management of medical waste is of great importance due to its potential environmental hazards and public health risks. In the past medical waste was often mixed with municipal solid waste and disposed of in residential waste landfills or improper treatment facilities (e.g. inadequately controlled incinerators) in Korea. In recent years, many efforts have been made by environmental regulatory agencies and waste generators to better manage the waste from healthcare facilities. This paper presents an overview of the current management practices of medical waste in Korea. Information regarding generation, composition, segregation, transportation, and disposal of medical wastes is provided and discussed. Medical waste incineration is identified as the most preferred disposal method and will be the only available treatment option in late Faced with increased regulations over toxic air emissions (e.g. dioxins and furans), all existing small incineration facilities that do not have air pollution control devices will cease operation in the next few years. Large-scale medical waste incinerators would be responsible for the treatment of medical waste generated by most healthcare facilities in Korea. It is important to point out that there is a great potential to emit air toxic pollutants from such incinerators if improperly operated and managed, because medical waste typically contains a variety of plastic materials such as polyvinyl chloride (PVC). Waste minimization and recycling, control of toxic air emissions at medical waste incinerators, and alternative treatment methods to incineration are regarded to be the major challenges in the future. q 2006 Published by Elsevier Ltd. Keywords: Medical waste; Hospital waste; Infectious waste; Incineration; Sterilization 1. Introduction In Korea, generation of medical waste from the healthcare industry has rapidly increased over the past decade. This type of waste results from the treatment, diagnosis, or immunization of humans and/or animals at healthcare facilities, veterinary and health-related research centers, and medical laboratories. Although medical waste represents a small portion of the total solid waste stream in Korea, such waste must be handled with care because of the potentially infectious and hazardous materials contained in it. Improper disposal of medical waste may pose a significant risk to human health and the environment. Some of the problems arising from poor management of medical waste may include damage to humans by sharp instruments, diseases transmitted to humans by * This paper presents an overview of the state-of-the-art knowledge on the management of medical waste in Korea. * Corresponding author. Tel.: C ; fax: C address: gogator@cnu.ac.kr (Y.-C. Jang) /$ - see front matter q 2006 Published by Elsevier Ltd. doi: /j.jenvman infectious agents, and contamination of the environment by toxic and hazardous chemicals. Thus, the management of medical waste is a subject of major concern for any regulatory agency. In Korea, medical wastes had been regulated by the Medical Law under the Ministry of Health and Welfare until These wastes were often mixed with municipal solid waste (MSW) and commonly disposed of in municipal landfill sites or improper treatment facilities. In addition, information on handling and disposal of medical waste from healthcare institutions was very limited and unknown. Facing the management problems of medical wastes, the Korea National Assembly modified the Waste Management Act in 1999 to better control medical waste from the point of generation to its final destination. The Korea Ministry of Environment (MOE) was responsible for implementing the Act. Medical waste is classified as designated (or hazardous) wastes and subject to hazardous waste regulations under the Waste Management Act. The Korea MOE promulgated several regulations for definition, segregation, packaging, tracking, and disposal of medical waste. Under the Act, medical waste is defined as any solid waste that is generated by medical treatment facilities and laboratory

2 2 Y.-C. Jang et al. / Journal of Environmental Management xx (2005) 1 9 Table 1 Classification of medical waste Waste category Components (1) Tissue Human or animal pathological wastes, including tissues, organs, blood, pus, and body parts and fluids that are removed during autopsy or surgery (2) Absorbent cotton Items (e.g. cotton pads, bandages, disposable diapers, or bedding) saturated or stained with human or animal blood, pus, discharge, or secretion (3) Discarded medical plastics Disposable syringe, IV bag, blood bag or waste from blood dialysis (4) Pathological waste Culture and stocks of infectious agents from test or examination, culture dishes, discarded blood fluids and containers; items that were in contact with infectious agents, such as used slides and cover glass (5) Waste sharps Discarded sharps, hypodermic needles, syringes, surgical blades and blood lancets (6) Waste mixed with infectious waste Wastes that are not classified into the above categories but mixed or in contact with waste class (1) through (5) above facilities operating in a hospital setting and is considered to be potentially hazardous to health. The waste includes animal carcasses, human body and animal parts, excretion and secretion from humans or animals, discarded plastic materials contaminated with blood, culture and stocks of infectious agents, discarded medical equipment, and other waste mixed with infectious agents. Specifically, the waste is classified into six major categories (Table 1). It is important to point out that the term medical waste has often been used interchangeably with other terms such as hospital waste and infectious waste around the world. Hospital waste is a more broad definition and refers to all wastes generated by hospitals including infectious and noninfectious waste materials, hazardous wastes and chemicals, and other non-hazardous wastes. Medical waste is often considered to be a subcategory of hospital waste and indicates potentially infectious waste that is produced from healthcare facilities (Klangsin and Harding, 1998; Levendis et al., 2001; Lee et al., 2002a). In this paper, medical waste refers to any potentially infectious wastes that are generated in the diagnosis, treatment, examination, or research by general hospitals, clinics, veterinary, and research centers, as listed in Table 1. Radioactive materials that have been used in medical examination and activities in a hospital setting (e.g. X-ray examination laboratory, X-ray treatment room) should be properly stored, transported, and treated to avoid any environmental and health hazards via beta and gamma ray emission. Wastes containing radioisotopes, such as P 32,H 3,or C 14, are separately regulated by the Atomic Energy Act in Korea. This paper presents an overview of medical waste management in Korea. The generation rates and characteristics of medical wastes are discussed in the following section. It also addresses the fundamentals of the actual situation in medical waste management and current disposal methods of the waste. Several suggestions are made to improve medical waste management practices in Korea. Data regarding the generation rates and composition of medical wastes from hospitals and air emissions of dioxins from medical waste incineration facilities were gathered from survey letters, hospital visits, conversations with hospital authorities, and available literature. We then evaluated the data obtained in this study to present an overview of the-state-of-the-art knowledge on the medical waste management in Korea. 2. Generation and composition of medical waste in Korea In order to develop proper waste management strategies, it is important to characterize the volumes and composition of the waste stream. The quantity of medical waste depends upon several factors such as the size of healthcare facility, the segregation program of medical wastes, and the medical activities. According to the Korea MOE, approximately 33, 980 tons of regulated medical waste were generated from 44, 478 healthcare facilities in 2002 (Korea MOE, 2003). Table 2 presents the quantities of medical waste generated from 1996 through In recent years, increased amounts of medical waste have been generated partly due to the stringent regulations for the waste and the wide acceptance of singleuse disposable materials (Table 2). It is important to note that medical waste has been classified into two major categories since 1999: tissues and others. Tissues are stored in a refrigerator, and all other wastes are placed and mixed in a large container at room temperature before waste treatment. Table 2 Quantities of medical waste in Korea Waste components Unit: ton /year Tissues Absorbent cotton ,512 a 20,726 a 26,784 a 33,062 a Discarded medical plastics Pathological waste Waste sharps Total 13,520 15,619 15,804 18,399 22,350 27,777 33,981 Source: Korea Ministry of Health and Welfare (1998), Korea MOE (1998 and 2003). a The numbers indicate all medical waste other than human and animal tissues.

3 Y.-C. Jang et al. / Journal of Environmental Management xx (2005) Table 3 Sources and quantities of medical waste in Korea in 2002 Waste components No. of generators Waste generated all facilities (ton/year) % Contribution by type of facility Veterinary institute Animal hospital Multi-specialty hospital Local public healthcare unit Medical research institute Clinics 38, Midwife unit General , hospital Blood banks Others (Crematory) Total 44,478 33, Source: Adopted from Korea MOE (2003). Waste generated per facility (ton per year) Sources and quantities of medical waste in Korea are shown in Table 3. National data show that medical waste generation is skewed toward the largest generators, which are general hospitals containing more than 100 beds. Approximately 60% of medical waste came from general hospitals, which account for only less than 0.7% of all generators. This indicates that such facilities are the largest source of medical waste when compared to other healthcare facilities. The average amount of waste generated per general hospital in 2002 was 68.5 ton. Taking into consideration that the total number of beds in general hospitals in Korea is 114,000 (Korea Association of Hospitals, 2003) and assuming that a bed-occupancy rate is 100%, the estimated generation rate of medical waste from general hospitals is 0.48 kg/(bed$day). This generation rate is comparable to those observed by other studies (Monreal, 1993; Pruss et al., 1999; Da Silva et al., (2005)). The amount of waste generated per clinic (e.g. physician, dental, and other outpatient clinics) is significantly lower (0.2 ton/year), although they represent more than 85% of all medical waste generators. This results partly from less intensive and routine medical care for outpatients provided by such clinics (e.g. single use materials for diagnosis). Therefore, they are often classified as minor and scattered sources of health-care waste according to the quantities produced (Pruss et al., 1999). Medical waste generally consists of many different types of materials. While the relative proportion of the components of medical wastes produced from hospitals depends upon the types of healthcare facilities, the management practices of waste (e.g. handling, segregation and disposal), and the regulations of waste, as a whole, the major components of medical waste include tissues, single-use disposable plastics, Table 4 Quantities and composition of medical waste in general hospitals in Daejeon metropolitan city Waste Unit: kg/year components Hospital A Hospital B Hospital C Hospital D Tissues Placentas Absorbent 70,239 35,040 20, cotton Discarded 39,217 39, medical plastics Pathological 13,953 26, wastes Waste sharps Mixture with 23,239 5,595 infectious waste Total 128, ,382 56,310 23,060 No. of bed Generation rate (kg/ bed$day) absorbent cottons, and pathological wastes. Although data regarding the quantities of medical wastes generated from healthcare facilities have been available, little is known about the detailed mass composition of medical wastes generated by this type of healthcare facility. Table 4 presents the quantities and mass compositions of medical waste produced by four general hospitals in Daejeon Metropolitan City in Korea based on a survey conducted during this study. Daejeon Metropolitan City is located in the middle of South Korea and has a population of more than 1.2 million. Major components of the wastes in the hospitals are absorbent cotton, discarded medical plastics, and pathological wastes. It was found that the generation rates of medical waste in the hospitals ranged from 0.14 to 0.49 kg/bed$day, assuming 100% bed-occupancy. While the generation rates from Hospitals A and B were comparable to the average value (0.48 kg/bed day) estimated by the national statistical data, a wide difference between the two hospitals and Hospital D was noted. Hospital D offers medical services mainly related to industrial work accidents. Inpatients at the hospital are generally admitted for a longer period of time, resulting in relatively lower turnover rate of patients. This indicates that a lower proportion of patients is treated on a day-care basis resulting in less medical waste produced by the hospital compared to the other hospitals. Another possible reason for the lower generation rate is that the healthcare services provided by Hospital D require less disposable plastics, pathological items, and absorbent cotton than the other three general hospitals due to different hospital specializations. 3. Medical waste management in Korea The best medical waste management practice for medical facilities is to prevent and minimize the generation of waste.

4 4 Y.-C. Jang et al. / Journal of Environmental Management xx (2005) 1 9 Medical waste Source Separation Recycling (Placentas) On-Site Off-Site (Manifest and On-line Tracking System) Incineration Steam Sterilization Incineration Steam Sterilization with Shredding Ash Disposal in Landfills Fig. 1. Current pathways for the management of medical waste in Korea. However, the potential for waste prevention and reduction at the point of generation are known to be somewhat limited because of the nature of the waste stream (e.g. the infectious characteristics) and the increased use of single-use disposable items. Fig. 1 illustrates the current pathways for the management of medical waste in Korea. The following section discusses each pathway of medical waste management Source separation and collection The segregation of medical waste is done at the point of generation and is commonly practiced in the majority of healthcare facilities in Korea. Human and animal tissues are placed in a red container (plastic, paper board, or metal container), while pathological waste and discarded sharps are stored in a yellow container. All other wastes are placed in an orange container before shipment. All containers exhibit the universal biohazard sign that is commonly used in many countries. In many cases, all segregated wastes other than tissues are then transferred to a larger medical waste container in a storage area before transportation to off-site treatment facilities for final disposal. Placentas are commonly separated in a red container and then used for raw materials in pharmaceutical products. Recycling of any segregated wastes other than placentas is not currently being practiced on-site Off-site transportation: manifest system and on-line tracking manifest Since medical waste is designated as hazardous waste, a manifest system is required for the management of medical waste. The uniform hazardous waste manifest system was created to track and better manage hazardous waste. The manifest form contains information on waste generator, transporter, and treatment facility, along with a characterization of hazardous waste being transported. Six copies (or four copies for small-size hospitals) of the form are initially completed and signed by generators before transportation. The generator retains one copy (Part #6) of the manifest and gives the remaining parts to the transporter. Upon arrival, the transporter retains one copy (Part #5) of the manifest and gives the remaining parts to the treatment facility. The treatment facility sends one copy (Part #3) to the original generator within 3 days, two copies (Parts #1 and #2) to local environmental agencies and retains one copy (Part #4). Manifests are not required for generators who treat the waste at their own on-site facilities. By using this manifest system, the generator and the local environmental agency can track the movement of medical waste from the point of generation and to the point of final destination. In 2002, an on-line manifest system was established to manage medical waste with a high degree of reliability and in real time. All of the parties (i.e. generators, transporters, and operators at medical waste treatment facilities as well as national and local regulatory agencies) who register with the on-line manifest system can track the movement of the waste and find out the status of the waste in real time, saving energy, cost, and time to manage the waste Medical waste treatment Several medical waste treatment methods, including incineration, steam sterilization (or sanitation), microwave sanitation, chemical disinfection, dry heat disinfection, and

5 Y.-C. Jang et al. / Journal of Environmental Management xx (2005) Fig. 2. Treatment methods of medical waste in 2002 in Korea (Source: Korea MOE, 2003). disinfection with superheated steam, may be used. As shown in Fig. 2, incineration and steam sterilization are currently being used as major treatment methods of medical waste. The major disposal option of medical waste from most healthcare facilities is to pay a licensed transporter to transport the waste to a medical waste incineration facility. As shown in Table 5, the most common method of medical waste disposal is off-site treatment, which accounts for approximately 90% of the total waste stream. The remaining waste (less than 10%) is treated by on-site incinerators or steam sterilization facilities at some general hospitals where incinerators or steam sterilization is available (Table 5). A total of 12 out of 292 general hospitals treat their own medical waste on-site by incineration, while two general hospitals employ steam sterilization with shredding of their medical wastes. Table 6 presents a list of on-site and offsite medical waste treatment facilities and shows the type of treatment and capacity of each Incineration In Korea, incineration has been a traditional treatment method to handle medical waste that typically contains infectious and hazardous materials. It has several advantages when used to treat medical waste, including a reduction in the waste volume, the sterilization and detoxification of the waste materials, and the recovery of heat or electricity during incineration. However, incineration has also some disadvantages, including the potential emission of toxic substances into the surrounding area, high operation and maintenance costs, and the requirement of ash disposal. The major type of incinerator used for the treatment of medical waste in Korea is a starved air incinerator. The starved air incinerator typically consists of two furnace chambers. In the first chamber, the waste is combusted with less than the stoichiometric air required, resulting in an effluent rich in organics. The off-gas is then burned out in the secondary chamber where more than the required (stoichiometric) amount of air (or oxygen) is provided for complete combustion. Operating conditions for incinerators required by the Korea MOE guidelines are greater than 850 8C within the secondary combustion chamber and at least 2 s of retention time of flue gas. All medical waste incinerators should also follow air emission standards for industrial settings to reduce air pollution potential. Medical waste incinerators can emit various toxic pollutants if the incinerators are improperly operated. Emissions from medical waste incinerators may include carbon monoxide (as a result of incomplete combustion), particulate matter, hydrogen chloride, metals (e.g. mercury, lead, arsenic, and cadmium) (Segura-Munoz et al., 2004), poly-cyclic aromatic hydrocarbons (PAHs) (Levendis et al., 2001; Lee et al., 2002b), and dioxins (polychlorodibenzo-p-dioxin (PCDD)) and furans (polychlorodibenzofuran (PCDF)) (Lee et al., 1995; Brent and Rogers, 2002; Fritsky et al., 2001; Matsui et al., 2003; Lee et al., 2004). In recent years, many general hospitals have stopped operating their on-site incinerators because of the stringent regulations of air pollutant emissions, especially dioxins, and the typical hospital s proximity to cities. The incinerators in the hospitals were often old with minimal emission control systems for air pollutants. Table 7 shows the emission standard for dioxins at incinerators set by the Korea MOE. Under the modified Waste Management Act, medical waste incinerators must measure dioxins more than once every year since Although the incinerators are required to measure PCDD and PCDF, limited data regarding the concentrations of PCDD and PCDF in air emissions from medical waste incinerators are available. Table 8 presents what data are available for dioxins and furans concentrations measured at several medical waste incinerators, which was provided by the Korea MOE. The results show that the dioxin concentrations notably vary among the incinerators. Average dioxin concentrations of air Table 5 On-site and off-site treatment of medical waste by in 2002 in Korea Unit: ton/year On-site treatment Off-site treatment Incineration Steam sterilization Incineration Steam sterilization Recycling Others (crematory) Tissues Others ,533 14, Total ,108 14, Source: Korea MOE, 2003.

6 6 Y.-C. Jang et al. / Journal of Environmental Management xx (2005) 1 9 Table 6 Current medical waste treatment facilities versus their treatment type and capacity (2003) On-site treatment Off-site treatment Facility Capacity (kg/h) Treatment type Facility Capacity (kg/h) Treatment type A 50 I a I B 150 I I C 30 I I D 400 I 4 350, 1000 I, S b E 190 I 5 710, 350 I, S F 190 I I G 100 I S H 190 I 8 320, 500 I, S I 190 I S J 25 I I K 700 S I L 250 S S M 170 S S N 30 I S O 120 I P 50 I Total 1715, 1120 I, S Total 8630, 5790 I, S a I, Incineration. b S, Steam sterilization (Source: Korea MOE, 2003). emissions from the medical waste incinerators were 9.23 ng- TEQ/Nm 3 in 2003 and 6.85 ng-teq/nm 3 in The average levels are clearly lower than the current dioxin standards (e.g. 20 or 40 ng-teq/nm 3 ), but some incinerators have the potential to exceed the new standard (e.g. 1 or 10 ng-teq/ Nm 3 ) coming in Thus, they will need to better control dioxin emissions. Further studies should be conducted to determine whether a number of the current medical waste incinerators are capable of complying with the new dioxin standard which is coming at the beginning of Many small-size on-site and off-site treatment facilities (Table 6) are likely to discontinue the use of existing incinerators in the near future, largely due to the stricter dioxin emission standards. Thus, only a limited number of large-size medical waste treatment facilities will remain, where advanced air pollution control devices can be used to control toxic pollutant emissions. However, some of the on-site incinerators may still treat their wastes at a rate of slightly less than 0.2 ton/ h (e.g. 190 kg/h) to avoid the increased regulations for dioxin emissions for large scale incinerators (10 ng-teq/nm 3 for ton/h capacity) (see Tables 6 and 7). Many air pollutants in emissions from medical waste incinerators can be significantly reduced by modern air pollution control devices if properly designed and operated. Typical air pollution control devices used at many medical waste incinerators in Korea include cyclones, semi-dry scrubbers, and baghouse filters (or fabric dust removers). Many devices can be modified to effectively control dioxins and furans. After incineration, the fly ash is disposed of in a hazardous waste landfill, while the bottom ash is characterized by the Korea Leaching Test to determine appropriate final disposal methods (hazardous or non-hazardous) Steam sterilization Steam sterilization (or sanitation) has also been commonly used for treating medical waste in Korea. Under the Waste Management Act, the medical waste collected in a plastic bag Table 7 Emission standards for dioxins at incinerators in Korea Capacity Emission standard (ng-teq/nm 3 ) Frequency of testing New Existing Medical waste incinerator 4 ton/h a or 1 b At least twice a year 2 4 ton/h 1 40 a or 5 b At least twice a year ton/h 5 40 a or 10 b At least twice a year kg/h 5 b 10 b!25 kg/h c c Municipal solid waste incinerator 2 ton/h (until June 30, 2003) 0.1 (July 1, 2003) At least twice a year a Until Dec. 31, b Beginning Jan. 1, c Incinerators no longer in use.

7 Y.-C. Jang et al. / Journal of Environmental Management xx (2005) Table 8 Dioxins in air emissions at several medical waste incinerators in Korea Medical waste incinerator Capacity (kg/h) or in a steel or plastic container should be shredded to less than 2 cm using appropriate shredding equipment prior to sterilization. The purpose of shredding is to convert medical wastes into a more homogenous form that can be easily handled and efficiently sterilized. After shredding, the waste is loaded into an autoclave for sterilization. This method is known to be very efficient when used for infectious waste and can be applied to most types of microorganisms, if the time and temperature of the reaction and contact between steam and waste are sufficiently provided to kill microbial spores (Ostler and Nielsen, 1998). Operating conditions for sterilization required by the Korea MOE are processing for more than 30 min. in contact with steam at 121 8C and above 1 atm. After steam sterilization, the final products are often incinerated at medical waste treatment facilities because many communities are reluctant to accept and dispose of the sterilized products in their MSW landfills. This results in a double treatment of medical waste, which becomes a less cost-effective approach for treating the waste. As a result, the Korean National Assembly recently passed new legislations eliminating the use of all existing steam sterilization units for medical waste treatment by August 8, This means that incineration will be the only available treatment option of medical waste in Korea in the near future. 4. Suggestions and future challenges Dioxins and furans in air emission (ng-teq/nm 3 ) Year 2003 Year 2004 Site a 0.09 Site 2 (a) , 1.31 (b) 600 a 1.25 Site Site Site 5 (a) (b) , 2.92 Site Site Average concentration (1.78 b ) a Not measured. b Average concentration without outlier (57.6). In the past few years many efforts have been made in Korea to better manage waste produced from medical institutions. A number of regulations and guidelines have been issued in order to establish an integrated medical waste management system. Since many of the measures initiated by the Korea MOE have only recently started, the outcome may still be difficult to evaluate. However, several suggestions can be made to improve current medical waste management practices in Korea. First, as stated earlier, the only available treatment option for medical waste after August 8, 2005 will be incineration. Alternative (and currently less developed) treatment methods to be used in the future depend upon the physical and chemical characteristics of medical waste. A certain component in the medical waste stream may require a different method of treatment, destruction, and disposal suitable to its own peculiarities. Thus, the development of alternative treatment technologies for medical waste (e.g. microwave sanitation, chemical disinfection, pyrolysis, and gasification) should be encouraged, replacing unnecessary incineration by potentially more environmentally friendly treatment methods. While incineration is a suitable treatment for most types of medical waste and has several advantages (especially volume reduction of medical waste, destruction of pathogens and hazardous organic matter), it is still an expensive method and may result in the production of many toxic emissions. For instance, dioxins and furans from medical waste incinerators may be easily formed and emitted to the atmosphere because the medical waste stream typically consists of a significant fraction of plastic materials containing polyvinyl chloride (PVC) products. It has been widely known that the incineration of medical waste is one of the major sources of dioxins and furans pollution partly due to the presence of PVC products (Walker and Cooper, 1992; Lerner, 1997; Vesilind et al., 2002). Medical plastic wastes include those associated with sharps (e.g. syringes), IV bags, IV solution containers, blood bags, tubing, gloves/lab ware, and medical packaging. Some of the materials (e.g. IV bags, IV solution containers, and blood bags) are typically made of PVC plastics that can serve as dioxin precursors. Concerns about dioxin air emissions are driving some efforts to reduce the use of PVC materials in medical products in the healthcare industry in some developed countries. Some researchers developed chlorine-free blood and IV fluid bags as an alternative to PVC to reduce dioxin air emissions when incinerated (Anderson et al., 1999; McCally, 1999). Therefore, in order to reduce the release of dioxins from incineration of medical waste, it is necessary to make efforts to recycle medical PVC plastics, study material substitution of the PVC products, and examine effective treatment methods for medical plastic wastes. Recycling of medical waste, especially discarded PVC products, is not currently practiced in most of the hospitals in Korea except for the use of placentas as raw materials in the manufacturing of pharmaceutical products. In addition, no efforts have been made to examine safer alternatives that exist for virtually all uses of PVC plastic products. In order to increase recycling of non-infected medical plastics such as medical plastic packages and IV solution bags, proper source separation should be undertaken after the modification of the current medical waste regulations. However, some arguments suggest that single-use disposable plastic products reduce liability, control infection, and minimize human exposure to hazardous or infectious chemicals. Second, waste minimization through reuse, recycling, and source reduction has to be promoted, which results in a decrease of medical waste to be disposed of. Programs for medical waste components separation at the source of production have not been successful in healthcare facilities to

8 8 Y.-C. Jang et al. / Journal of Environmental Management xx (2005) 1 9 promote material recycling (e.g. glass, plastic) because of a major concern over the infectious characteristics of the waste and the regulations that do not allow recycling and reuse of any of the medical waste components. However, many waste components produced in hospitals might be recyclable if they are not infected, contaminated, and not used for medical activities. The components include the plastics and metals in syringes, infusion tubing and bags, and the glass in tubes and vials. Purchasing easily recyclable, less hazardous, or reusable items will expedite waste minimization efforts in the subsequent waste management process. Third, although medical wastes are defined and classified into six major categories, composition data of medical waste in national statistics have been divided into only two major categories (i.e. tissues and others). Thus, proper medical waste management strategies to be applied are very limited. More detailed categories are needed to better understand the physical and chemical characteristics of medical waste and to develop best waste management practices, rather than relying solely on incineration. Finally, dioxins and furans data at medical waste incinerators are not readily available, although the toxic pollutant measurements have been required by the regulations in recent years. Considering the fact that incineration is the dominant disposal method of medical waste in Korea, more dioxin data are needed to assess potential risks to humans and the environment near medical waste incinerators. In addition, characteristics of incinerated medical waste ash should be closely investigated prior to final disposal since it too may contain a variety of toxic substances. 5. Conclusion The generation of medical waste in Korea has been increasing in quantity and variety, due to the wide acceptance of single-use disposalable items (e.g. gloves, plastic syringes, medical packages, bedding, tubing, IV bad and containers). The management of medical waste has been of major concern due to potentially high risks to human health and the environment. In the past, medical waste was often mixed with household waste and disposed of in municipal solid waste landfills. In recent years, increased public concerns over the improper disposal of medical waste have led to a movement to regulate the waste more systematically and stringently by the Korea Ministry of Environment. Waste minimization and recycling are still not well-promoted, which results in significant amounts of medical waste to be disposed of. Efforts have to be made for minimization and recycling of medical waste prior to final disposal, especially many medical PVC wastes and plastics, if not infected or contaminated. Incineration will be dominant as a medical waste treatment in Korea because another common treatment method, steam sterilization, will no longer be available in the near future. Therefore, toxic substances such as dioxin emissions at medical waste incinerators should be closely monitored to reduce potential risks to humans and the surrounding environment. Other potential treatment technologies, such as pyrolysis and microwave disinfection, should be examined as alternatives to incineration in order to better manage medical waste in Korea. Acknowledgements This study was funded by the research grant (# ) at the Chungnam National University. The authors gratefully acknowledge the assistance of Dr Jae-Hyuk Hyun from Chungnam National University and Dr Jenna R. 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