[Medical waste incinerator constructed with locally produced materials: experience during the immunization campaign 2002 against measles in Douala, Cameroon].

Unlabelled: Incineration is still the method of choice for disposal of biomedical waste. Combustion at 800+ degrees C eliminates all risk of injury by reducing the waste to ashes and destroying all microorganisms. The purpose of his report is to present a modular double-chambered incinerator in conformity with recommendations for developing countries. The incinerator described here provides the following advantages: suitability for low-cost artisanal construction, excess-air combustion, low risk of accidents and contamination, after-burner for smoke, energy efficiency, easy operation/maintenance, and safety. It is made from locally produced clay bricks reinforced with a steel frame and features two chambers for combustion and post-combustion. It functions on a batch basis with a 2-hour cycle. The immunization campaign against measles that was carried out in 5 districts of Douala in December 2002 produced 800,000 self-disabling syringes with needles. These by-products were immediately discarded in cardboard safety boxes (5-liter capacity, 1 kg) that were taken to the incinerator and burned at the rate of two batches per day.

Results: The construction cost of the incinerator was 3,500,000 FCFA (5,300 euros). A total of 5,816 boxes were incinerated, i.e., 29,080 litres, 872,400 syringes, 6,281 kg. Incineration required 126 batches over a period of 11 weeks. The ashes (240 litres, i.e. 0.8% of the total incinerated volume) were virtually free from solid residue. Fuel consumption was negligible. Smoke was never excessive, thick or odorous. Temperatures measured during preliminary trials were always above 800 degrees C. According to the WHO, toxic emissions are negligible if incineration is carried out at temperatures higher than 700 degrees C for less than 2 hours a day. Further study will be necessary to confirm this preliminary experience with regard to temperature control and smoke/ash composition and to test the incinerator in various climatic and operating conditions.