醫療院所含銀廢棄物：產生量與回收清理方式之調查研究

Generation and Recycling Study of the Silver-BearingWastes from Medical Hospitals in Taiwan

含銀物料廣泛應用於醫療院所，但廢棄時如未能妥善清理，可能藉由生物濃縮作用，干擾人體的新陳代謝，對環境與人體健康造成威脅。國內對於含銀物料在醫療院所的產生源、廢棄量、回收、清理等尚無完整的調查。因此，本研究以國內50床以上醫療院所為研究對象，設計含銀物料使用與廢棄物之分類、回收及清理現況的專用調查表，共完成334家的醫療院所訪查。依調查結果彙整顯示，含銀物料的使用以放射診療部門為主，項目包括X光片、定影劑、顯影劑，國內醫療院所X光片每月每單位病床使用量為16.68片、定影劑1.60公升與顯影劑1.45公升。於含銀廢棄物的產生量則為廢X光片每月每單位病床產生2.77片、廢定影劑1.83公升與廢顯影劑1.81公升，其中僅有廢定影液含銀而具回收價值，由醫療院所或藥劑供應場商回收處理。雖然醫療院所約有85%設置有銀回收設備，但大多數含銀廢液經由含銀回收設備處理後，廢液中的銀離子濃度仍高於法規標準（>5ppm），顯示含銀回收設備之裝置，未能達到預期的處理效率，且回收所含有價金屬銀後，殘餘廢液仍排放進入醫療院所廢水處理單元，但仍有高濃度的COD與氨氮，對處理程序與排放水體環境亦造成影響。國內醫療院所多以人體醫療為第一目標，但仍建議醫療院所多瞭解相關環保法令規定，規劃妥善相關廢水與廢棄物的回收清理方式，以善盡醫療院所之社會與環境責任。

The silver-bearing materials are widely used in medical hospitals. As discarded, if not properly handled, it may pose a severe threat to the environment and human health. The major threat to the environment is the bio-concentration effect, which leads to interfere with the metabolism of the upper food chain of animals. Currently there is a lack of the total amount of silver-bearing materials in medical hospitals, so as its waste collection and recycling program. This study completed a total amount of 334 medical hospitals (>50 beds) with on-site investigation. The investigation results indicate that the silver-bearing material, including X-ray film, film fixer, and film reagent, mainly generated from the radiological services. According to the estimation of this study, the monthly amount used per bed is 16.68 plates for X-ray film (14´ 17 inches), 1.60 liters for film fixer, and 1.45 liters for film reagent. In addition, the monthly amount for waste X-ray film is 2.77 plates, 1.83 liters for waste film fixer, and 1.81 liters for waste film reagent. The generation ratio for waste film fixer is 1.14, indicates that the flow of waste film fixer is still unclear. This study also shows that about 85% medical hospitals have installed the silver recovery equipment. However, most of the waste film fixer collected after the silver recovery equipment has a silver ion concentration higher than the regulatory standard (> 5 ppm). These results indicate that the silver recovery equipment may be operated in a low efficiency, and the waste film fixer can be still discharged into the wastewater treatment plant or sewer system of the medical hospitals. The effluent even after treatment may still contain high concentrations of COD and ammonia nitrogen that are highly impact on the treatment processes and receiving water environment as well. Although the medical hospitals have set the human health care the primary goal, this study suggested that they should pay great attention to the environmental bylaws. Additionally, a proper recycling scheme for silver-bearing wastes generated from the medical hospitals should be programed so as to secure social responsibility and better environmental quality in Taiwan.