Generation and composition of waste from medical histopathology laboratories

The aim of this work was to record the quantities and composition of medical waste (MW) generated by public and private medical histopathology laboratories (HISTOLB) and to provide pertinent waste generation design coefficients (e.g. g/examinee) for those laboratories. This can be a useful coefficient when designing medical waste treatment facilities. The study was conducted on three public and four private HISTOLBs in the city of Thessaloniki (Greece) for a period of 5 months. One sampling week was selected randomly per month. During the study period, the examinees per week were 108 and 90 in the public and private HISTOLBs, respectively. According to the results, 57% of the total MW generated in both the public and private laboratories were toxic waste (TXW), namely the liquid formaldehyde that is used to preserve the tissue. The mixed hazardous waste (MHW) comprised 28% and 24%, respectively, of the total MW, in the public and private facilities, respectively. The infectious waste constituted around 15% of the total MW generated in both types of facilities. Urban type waste was always less than 4% by weight. The total mean MW generated in the public and private laboratories were 208 ± 543 (n = 1614) and 195 ± 512 (n = 1789) g/examinee, respectively. A large variance among the mean MW generation rates of the participating individual laboratories that belonged to the same category was observed. The dominant fraction of the infectious waste was the plastic containers that contained the tissue samples, being around 75% of the total infectious waste, followed by the latex gloves (being around 17% of the infectious waste).