airborne microplastic pollution in healthcare waste disposal systems: a cross-sectional study in tehran

Introduction: microplastics (mps) pollution has become a significant global environmental concern, with various sources contributing to its spread. however, the release of mps from healthcare waste disposal systems, which often involve shredding plastic waste, has not been widely studied. this research investigates the presence and concentration of mps in the air surrounding autoclave and hydroclave devices at hospital waste disposal sites in tehran.materials and methods: a cross-sectional study was conducted from may to august 2024 in eight hospitals in tehran, encompassing both autoclave and hydroclave systems. air samples were collected from distances of 0,5, and 10 m from the waste management units during their operation and when they were off. a total of 48 samples were analyzed for microplastic particles using light microscopy and raman spectroscopy to determine particle characteristics such as size, shape, and color.results: the average concentration of mps in the air surrounding autoclave and hydrocalve devices was 45±43 (n/m3) and higher concentrations were observed when the devices were active. no significant differences were observed between the autoclave and hydroclave systems. microplastic particles in the air of the disinfected areas were mainly fibrous (95%) and black (70%), and the average particle length was 34.93 μm. smaller particles, which pose more health risks, were the most common particles. conclusion: hospital waste disposal units, especially their shredder systems, are a significant source of airborne mps. these emissions, especially through inhalation are a potential health risk. this study highlights the need for further research and mitigation strategies to reduce microplastic emissions in healthcare settings.