Ecological and economic impact of a misbelief in a CPU

Context
Waste from a cytotoxic preparation unit (CPU) are hazardous. Hospitals are responsible for waste management and disposal. CPU waste is a type of medical waste (MW) and must be incinerated. MW management is both economically and ecologically costly for the hospital.

Objective
To raise awareness among the CPU team of the need to manage MW based on ecological and economic considerations. The team is in the habit of changing waste containers (C) at the end of the day, regardless of how full they are, in order to start the next day’s production with empty C. The reason behind this practice is to avoid having to change C during production.

Materials and methods
The number of C used per day and, whether, these changes occurred during the course of the CPU production, were recorded on a double-station isolator, over a period of 1 month. Data was collected according to 2 systems: for system A, a change if C was full; for system B, a change if C was full and at the end of the day. The cost of a C is €50, and as MW is regulatory incompressible a C represents a volume of 50L for both systems. MW is collected by a service provider and transported in 800-litre transport containers (TC) by truck, with a capacity of 12 TC, to a processing centre 8 km away.

Results
For a double-station isolator over 1 month, we obtained 38 C for system A, including 32 changes during activity, and 50 C for system B, including 27 changes during activity. There was a non-significant difference in the number of in-process changes per day (p=0.0574, Mann-Whitney, 5%), and a significantly higher number of C per day for system B (p=0.0005, Mann-Whitney, 5%).

Discussion
This study shows that the 2 systems have the same impact on the team’s activity. Our CPU has 5 workstations, and extrapolating from this, one year’s production would generate 1140 C and 1500 C for systems A and B respectively. If we opt for system A, this means a reduction of €18,000 in the purchase of C and 18,000L in the volume of MW generated compared with system B. This difference in volume represents the reduction per year of 2 MW collecting trucks, i.e. a reduction of 28 kg of CO2 linked to transport (1), which is equivalent to the energy consumption of a refrigerated unit over 5 months (2). The carbon impact linked to the production and radiosterilisation of C by the supplier, as well as the cost and carbon impact of disposing of MW, could complete this data, but could not be obtained after soliciting the various parties involved. This action has raised awareness among CPU team of the ecological and economic impact of a simple change in practice that does not alter working conditions. MW is a current issue, and CPU pharmacists have a role to play in rationalising their generation.

1. Carbon Calculator Form | GEODIS [Internet]. [cité 16 juin 2023]. Disponible sur: https://geodis.com/w-fr/geodis_carbon_calculator/form#
2. Impact sur le climat des objets et gestes | Impact CO2 [Internet]. [cité 16 juin 2023]. Disponible sur: https://impactco2.fr//

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