Aflatoxins in Municipal Solid Wastes Compost? A First Answer

The occurrence of potential mycotoxins producing Aspergillus molds in municipal solid waste (MSW) and MSW compost was investigated. Among the strains isolated, five were potential mycotoxin producers and three of them actually produced aflatoxins or sterigmatocystin in vitro when cultured in liquid complex medium. However, no mycotoxin was recovered from MSW composts. A possible interaction between aflatoxin B1 and compost components was suggested. A single chloroform extraction allowed 32% of added aflatoxin B1 to be recovered while 73% was recovered after eight extractions. Because of the possible interaction between compost and aflatoxin B1 pointed out by this experiment, it was impossible to conclude that aflatoxin B1 was actually absent in MSW compost. This should be investigated further in order to assess the risks associated with MSW composting and mycotoxins exposure. Keywords: Municipal solid waste; compost; mycotoxins; humic acids; adsorption