Ferdowsi Ali, Ferdosi Masoud, Mehrani Mohammd Javad
Faculty of Environmental Engineering, Tarbiat Moallem University of Tehran Shahid Mofatteh St, Tehran, Iran.
Mater Sociomed. 2013 Mar;25(1):48-51. doi: 10.5455/msm.2013.25.48-51.
Medical wastes are among hazardous wastes and their disposal requires special methods prior to landfilling. Medical wastes are divided into infected and non-infected wastes and the infected wastes require treatment. Incineration is one of the oldest methods for treatment of medical wastes, but their usage have faced wide objections due to emission of hazardous gases such as CO2 and CO as well as Carcinogenic gases such as Dioxins and Furans which are generated as a result of incomplete combustion of compositions like PVCs. Autoclave is one the newest methods of medical wastes treatment which works based on wet disinfection.
The statistical population in this descriptive, comparative study includes hospitals located in Isfahan city and the sample hospitals were selected randomly. To environmentally evaluate the Autoclave method, TST (time, steam, temperature) and Spore tests were used. Also, samples were made from incinerator's stack gases and their analyses results were compared with WHO standards.
TST and spore tests results were negative in all cases indicating the success of treatment process. The comparison of incinerator's stack gases with WHO standards showed the high concentration of CO in some samples indicating the incomplete combustion. Also, the incineration efficiency in some cases was less than 99.5 percent, which is the efficiency criterion according to the administrative regulations of wastes management law of Iran. No needle stick was observed in Autoclave method during the compaction of bags containing wastes, and the handlers were facing no danger in this respect. The comparison of costs indicated that despite higher capital investment for purchasing autoclave, its current costs (e.g. maintenance, etc) are much less than the incineration method.
Totally, due to inappropriate operation of incinerators and lack of air pollution control devices, the use of incinerators doesn't seem rational anymore. Yet, despite the inefficiency of autoclaves in treatment of bulky wastes such as Anatomical wastes, their usage seems logic considering the very low amounts of such wastes. Also, considering the amount of generated wastes in Isfahan hospitals, a combination of centralized and non-centralized autoclaves is recommended for treatment of infected wastes. Mobile autoclaves may also be considered according to technical and economical conditions. It must not be forgotten that the priority must be given to the establishment of waste management systems particularly to personnel training to produce less wastes and to well separate them.
医疗废物属于危险废物，其处置在填埋前需要特殊方法。医疗废物分为感染性和非感染性废物，感染性废物需要进行处理。焚烧是处理医疗废物最古老的方法之一，但由于排放诸如二氧化碳和一氧化碳等有害气体，以及因聚氯乙烯等成分不完全燃烧产生的致癌气体如二噁英和呋喃，其使用面临广泛反对。高压灭菌器是基于湿式消毒的最新医疗废物处理方法之一。
在这项描述性、对比性研究中，统计总体包括位于伊斯法罕市的医院，样本医院是随机选取的。为从环境角度评估高压灭菌器方法，使用了TST（时间、蒸汽、温度）和芽孢检测。此外，从焚烧炉的烟囱气体中取样，并将其分析结果与世界卫生组织标准进行比较。
所有情况下TST和芽孢检测结果均为阴性，表明处理过程成功。焚烧炉烟囱气体与世界卫生组织标准的比较显示，一些样本中一氧化碳浓度较高，表明存在不完全燃烧。此外，在某些情况下，焚烧效率低于99.5%，而这是根据伊朗废物管理法行政法规的效率标准。在压实装有废物的袋子过程中，高压灭菌器方法未观察到针刺情况，处理人员在这方面没有面临危险。成本比较表明，尽管购买高压灭菌器的资本投资较高，但其当前成本（如维护等）远低于焚烧方法。
总体而言，由于焚烧炉操作不当且缺乏空气污染控制装置，焚烧炉的使用似乎不再合理。然而，尽管高压灭菌器在处理诸如解剖废物等大量废物方面效率不高，但考虑到此类废物数量极少，其使用似乎是合理的。此外，考虑到伊斯法罕医院产生的废物量，建议采用集中式和非集中式高压灭菌器相结合的方式处理感染性废物。也可根据技术和经济条件考虑使用移动高压灭菌器。不应忘记的是，必须优先建立废物管理系统，特别是对人员进行培训，以减少废物产生并妥善分类。
