A system dynamics approach for HCWM: a case study in Istanbul Metropolitan City
Healthcare waste consists of various types of waste materials generated at hospitals, medical research centres, clinics and laboratories. Although 75-90% of this waste is classified as 'domestic' in nature, 20-25% is deemed to be hazardous, which if not disposed of appropriately, poses a risk to healthcare workers, patients, the environment and even the whole community. As long as healthcare waste is mixed with municipal waste and not segregated prior to disposal, costs will increase substantially. In this study, healthcare waste increases along with the potential to decrease the amounts by implementing effective segregation at healthcare facilities are projected to 2040. Our long-term aim is to develop a system to support selection and planning of the future treatment capacity. Istanbul in Turkey was used as the case study area. In order to identify the factors affecting healthcare waste generation in Istanbul, observations were made and interviews conducted in Istanbul over a 3 month period. A system dynamics approach was adopted to build a healthcare waste management model using a software package, Vensim Ple Plus. Based on reported analysis, the non-hazardous municipal fraction co-disposed with healthcare waste is around 65%. Using the projected waste generation flows, reducing a municipal fraction to 30% has the potential to avoid some 8000 t year(-1) of healthcare waste by 2025 and almost 10 000 t year(-1) by 2035. Furthermore, if segregation practices ensured healthcare waste requiring incineration was also selectively managed, 77% of healthcare waste could be diverted to alternative treatment technologies. As the throughput capacity of the only existing healthcare waste treatment facility in Istanbul, Kemerburgaz Incinerator, has already been exceeded, it is evident that improved management could not only reduce overall flows and costs but also permit alternative and cheaper treatment systems (e.g. autoclaving) to be adopted for the healthcare waste.