Gestion des déchets biomédicaux solides, impacts socio-environnementaux et modélisation d’un incinérateur artisanal amélioré

Abstract

Solid Biomedical Waste (SBW) is a health and environmental problem. A study was conducted in certain regions (North, Adamaoua, East, North-West) of Cameroon to develop a biomedical waste management system, the implementation of which will improve public health while respecting environmental, technical and socio-cultural concerns. The description and the observation of the behaviors of the personnel of the hospital were oriented towards the objectives of the study. The sample represented by the health facility managements (HFM), department heads, service supervisors, hospital hygiene managers, waste collection agents and care staff as well as incinerator operators allowed to appreciate the management of SBW. The collection of data was carried out through the services which are in charged of the maintenance, the analysis of the treatment systems and the documentary analysis. In addition, tools for identifying impacts by Leopold's matrix and Martin Fecteau's grid enabled us to characterize and evaluate the impacts that SBW generate on the environment. In addition, tests were carried out on improved artisanal modeling on components such as: fumes and ashes during the various hours of the day as well as at different temperatures. The results obtained show that the quantification and characterization of hospital solid waste gives 96.88 kg / day on average, ie 35.36 tons of solid biomedical waste per year and 135 kg per day of ordinary waste. Non-hazardous waste treated as garbage represents 63% of all waste produced in the hospital and consists of paper, the rest of meals, cardboard, plant debris, waste care activities (37% ) consist of syringes, scalpels, cottons, anatomical waste, pharmaceutical products. The latter are largely represented by the fermentable material and bulky waste mainly consisting of old beds and non-medical equipment. The lack of human, material and financial resources, the lack of awareness and training of hospital staff affect the proper management of SBW, and expose staff to infectious, psycho emotional, traumatic and object-related injuries sharp or splashed with blood. In terms of the environment and health, prolonged storage of waste is responsible for nosocomial infections and olfactory nuisances. The staff of the various facilities, the collection agents, the patients and the public daily traumatic and emotional risks. Accidents that occur through stings or injuries are responsible for 30% in most cases of viral and contagious diseases such as hepatitis C, hepatitis B and AIDS. It shows that poor management of DBMS creates environmental risks. Beside that we had, a pollution of the ground to 22 %, a pollution of the air to 45 %, a pollution of the water to 27 %, an attack with the water table to 4 % and a contribution to climate change to 2 %. Out of 70 health facilities surveyed, 70 % of the hospitals have no incinerators, 25 % of the FOSA have defective incinerators and 5 % have incinerators that do not control the operation. However, a field study has established an improved artisanal incinerator meeting the requirements of the hospitals. Analysis of the components (fumes and ash) of this system shows that the cycle of incineration of SBW at various times of the health activities at a constant temperature of 1100 ° C produces ash and fumes ranging between 0.5 and 1.30 respectively. kg for the first component and between 10ppm for CO, 20 % for O2, absent for CH4, 0.01ppm for H2S for the second. The energy modeling of the system shows the energy balance of the system is zero because the incoming elements (waste, air, water) are equal to the outgoing elements (gas, ash, losses, water) with a value of 618 kj / kg. In addition, the environmental modeling presented results that are relevant in terms of aspects, environmental with a CO emission rate of 2 %, and a total absence of methane (CH4) and hydrogen sulphide (H2S); social with a simplified local manufacturing. Those which allows an economic modeling with cost of realization of 690 000 FCFA. In view of the observations made, an improvement of the solid biomedical waste management system is indispensable.