THE CYTOTOXIC POTENTIAL OF HOUSEHOLD WASTE DURING COMPOSTING

During the last 10 years an increasing number of plants for re-use of refuse have been constructed in Europe and the U.S.A. During the same period several cases of occupational respiratory diseases among worker s have been reported in the recycling industry. The aim of this projec t was to show, in vitro, if there is any change in the cytotoxic poten tial of garbage dust during the process of converting household waste to compost. Two cell lines have been exposed to extracts of waste fuel pellets and compost, taken from three different time periods in the c omposting process. Significant differences were found in the cytotoxic potential of extracts of household waste (P<0.05). Extracts of 0.48 m g well(-1) raw compost, fresh compost and matured compost show a cytot oxic effect at 97, 41 and 44%, respectively of unexposed cells. In con clusion, these results show the greatest cytotoxic potential when the microbial activity seems to be at its height in the composting process . Earlier, studies on the effect of endotoxin (lipopolysaccharide, LPS ) on the cells, and with pure endotoxin did not find any cytotoxic eff ect in the assay. Further investigations are needed in order to find w hich micro-organisms or components from these are responsible for the cytotoxic potential. (C) 1997 ISWA.