Clostridium botulinum and bio-compost. A contribution to the analysis of potential health hazards caused by bio-waste recycling.

Bio-waste recycling and the production and use of bio-compost are politically encouraged in Europe. Quality control takes no consideration of pathogenic anaerobic spore formers, e.g. Clostridium botulinum. A protocol for health hazard analysis concerning this pathogen has been developed. Samples of marketed bio-compost were tested and results showed that about 50% of the tested samples contained C. botulinum. For the first time it has been shown that the use of bio-compost represents a health hazard to humans and animals, especially in the future when spores will have accumulated in the environment. The use of household bio-waste collected in 'bio-bins' is apparently one factor involved in the production of contaminated compost end-products. Environmental factors in the propagation of C. botulinum are discussed. The improvement of bio-waste recycling technology and management should be encouraged in order to minimize the health hazard caused by contaminated bio-compost.