Thesis (M. Sc.)--University of Hong Kong, 2000. / Includes bibliographical references (leaves 76-81).

published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management

Biohazardous waste refers to wastes that are potentially infectious to humans, as well as wastes from animal or plant research that could be potentially infectious to these organisms, or could alter their genetic selection process. Research resulting in generation of biohazardous waste is typically conducted at large, research-based universities. The purpose of this study was to examine how 122 universities manage their biohazardous waste through a survey of environmental health and safety professionals responsible for waste management at these institutions. Based on the data collected from this survey (82.6% response rate), university biohazardous waste policies are heavily influenced by state environmental regulations, the OSHA Bloodborne Pathogens Standard, and CDC/NIH biosafety guidelines. Biosafety or hazardous materials professionals are the individuals most likely to be responsible for program administration. Contaminated wastes, both sharps and non-sharps, are almost exclusively treated as biohazardous waste by these institutions if they are a potential infection risk to humans. They are also likely to be treated as biohazardous waste if they are an infection risk for animals but less likely to be treated in this manner if they are a potential infection risk for plants. Over 70% of the universities indicated that they are using a licensed medical waste hauler for some portion of their waste. Even so, 90% of universities use sterilization by autoclave for waste treatment, yet only 52% of those users indicated validation of the process using a biological indicator. Forty-two percent of respondents currently use incineration for waste treatment. Of those incinerators, roughly half (22 of 42) are HMIWI's. Ten of the twenty-two HMIWI's will continue to operate under EPA's revised regulations for these processes. To assure compliance with institutional policies, most universities require segregation and packaging of waste, training for waste generators, and inspections of waste generating areas. Biohazardous waste definition and management in large universities is variable, and is the likely result of the diversity of activities that contribute to waste generation as well as state-specific environmental requirements in addition to other regulatory and guideline issues that need to be addressed in a comprehensive management program. / Graduation date: 2000

The disposal of infectious medical waste has become a major environmental concern. New disposal methods are currently being investigated; one of these is a bioremediation process which utilizes enzymes in a batch reactor to render the waste noninfectious. The success of this biological process depends on (among other things) two mechanisms: the diffusion of the disinfecting enzymes into small crevices within the waste stream and the breakdown of cellulose-derived material by cellulase enzymes. It was found that the waste stream contained a variety of small crevices which could possibly contain pathogens. Circulation in these crevices was restricted by their small openings and one must rely on diffusion of enzymes to disinfect their interiors. Numerical models for the diffusion of enzymes within one-dimensional and re-entrant crevices were developed and a method for comparing various re-entrant crevices was presented. From these models a conservative method for determining approximate disinfection times for the crevices was described. It was determined from this conservative method that most crevices within the waste will either be disinfected during the process or shortly thereafter. This biological process also utilizes cellulases to breakdown the paper within the waste stream. Small-scale simulated waste experiments were conducted with cellulases to determine the increase in maximum mixable solids concentration and the mass reduction of the waste due to cellulase activity. The addition of cellulases to the slurry more than doubled the waste concentration which could be agitated and reduced the agitator shaft power by as much as 50% when compared to the simulated waste tests with no cellulase. Significant mass reduction was also observed with the addition of cellulases to the slurries. Small-scale breakdown experiments were conducted with and without cellulases using newsprint as the substrate. These experiments were performed to determine the influence of cellulose hydrolysis by cellulases on agitator power. A simple mathematical model was developed and presented which described this phenomenon. / Master of Science

PhD (Public Health) / Department of Public Health / Medical waste is a special type of hazardous waste generated from healthcare facilities. Mismanagement of this waste has a negative impact on healthcare workers, patients and their relatives, medical waste handlers and the community. South Africa, like many other developing countries, is resource-constrained in the management of medical waste and poor practices have been reported across the country, especially in the urban health facilities that have received more attention from researchers. This study was conducted to explore the practices and challenges of medical waste management in Vhembe District, a largely rural district in Limpopo province and develop intervention strategies for better management of the waste in the District. A convergent parallel approach of mixed method design was adopted to achieve the objectives of this study. The target population included the main stakeholders of medical waste management in the district: the Department of Health, healthcare facilities and the waste management company responsible for the treatment and disposal of medical waste in Limpopo Province. The study population from the Department of Health included representatives from the medical waste management section while the waste management company was represented by the manager of the company in Limpopo Province. The samples for the healthcare facilities were drawn from fifteen randomly selected healthcare facilities in the district and included the administrative heads, medical waste generators and medical waste handlers. The study was conducted in three phases. Phase 1 was a qualitative study during which the administrative heads of the selected healthcare facilities, personnel directly involved in medical waste management at the healthcare facilities as well as the representatives from the Department of Health and waste management company were engaged in in-depth interviews. This phase also involved voice recording, observations, field documentation and taking of relevant pictures. Thematic content analysis was used to analyze the data obtained. During phase 2 (quantitative study), a semi-structured questionnaire was employed for data collection from medical waste generators and handlers at the healthcare facilities. A total of 229 questionnaires were retrieved from the participants and were analyzed with the Statistical Package for Social Sciences version 25.0. Descriptive statistical analyses were performed; Chi-square and Cramer’s V tests were used to determine the associations between dependent and independent variables, as well as the strength of association where significant relationships exist. Statistical significant level was set at p<0.05 and the results are presented in tables and graphs. The results from both phases were interpreted and discussed simultaneously. Respondents and participants were assured of anonymity of their identities and confidentiality of the information they provided. They were given adequate information about the study and only those who volunteered participated in the study after appending their signatures on the informed consent form. In phase 3, the Medical Research Council Framework was used to develop intervention strategies for improved medical waste management in Vhembe District based on the Strength, Weakness, Opportunity and Threat (SWOT) and Political, Economic, Social, Technological, Environmental and Legal (PESTEL) analysis techniques. The study revealed inefficient practices of medical waste management in all the healthcare facilities. Rate of medical waste generation was 338.15kg/day, 19.2kg/day and 15.5kg/day of HCRW from the hospitals, community health centers and clinics respectively. Segregation practices were poor, and only 28.4% of respondents rated their healthcare institutions as being excellent with medical waste segregation. The type of occupation was found to be significantly associated with exposure to training (p=0.000) and the level of knowledge about medical waste management (p=0.000). Also, the use of personal protective equipment was found to be significantly associated with training (p=0.011). Transportation and temporary storage were not done according to the recommendation in the guidelines and incineration was the main means of treatment of the waste. The final product of waste treatment is being disposed into an hazardous waste landfill. The challenges encountered in the process of managing medical waste include lack of adequate funding and budget for medical waste management, ineffective and irregular training of healthcare workers, non-compliance to medical waste management guidelines, insufficient bins, substandard central storage rooms, insufficient personal protective equipment and unavailability of Hepatitis B vaccine. The strength, weakness, opportunities and threats of medical waste management in Vhembe District were analyzed and specific intervention strategies were developed to improve on the strength, minimize the weakness, take advantage of the opportunity and combat the threats. The developed strategies were validated. This study provides the evidences of poor management of medical waste in Vhembe District, and shows the need for urgent intervention measures to be put in place. We therefore recommend that the intervention strategies proposed here be evaluated and implemented to mitigate the untoward effects of poor medical waste management among healthcare workers and the community as a whole. / NRF