Occurrence of Enteric Pathogens in Composted Domestic Solid Waste Containing Disposable Diapers

Abstract

Information has not been previously available on the occurrence of enteric pathogenic viruses and protozoan parasites in composted municipal domestic solid waste. A potential source of these pathogens in domestic solid waste is disposal diapers. The occurrence of enteroviruses, Giardia cysts, Cryptosporidium oocysts and Salmonella were determined in municipal composted domestic solid waste, and solid waste to which extra diapers had been added to increase their concentration 2-4 fold (6.6-7.7% by weight) above that found normally in municipal solid waste before composting. The compost was tested at various periods of time during aging (101-203 days). No enteroviruses or protozoan cysts or oocysts were detected in any of the samples collected during this period. One sample out of 19 collected (after 175 days aging) was positive for Salmonella. These results suggest that enteric pathogens were destroyed during the composting process, or were present in numbers below the detection method (i.e. one organism per 40-50 g of compost) used in this study.

A review of the effectiveness of current time–temperature regulations on pathogen inactivation during composting

“…Recontamination of the compost pile from external sources and (or) regrowth from undetectable levels is one potential explanation for bacterial pathogen presence beyond the high-temperature phase (Haug 1993;Gerba et al 1995;Epstein 1997;Dumontet et al 1999). Regrowth is a problem only for certain bacterial pathogens such as Salmonella sp., and E. coli which, unlike other bacterial species, viruses, protozoa, and helminths, do not require a host organism to reproduce (Haug 1993;Rubin 1996;Jones and Martin 2003).…”

“…In other words, temperature monitoring and (or) reporting may falsely give the impression that the time-temperature criteria have been met throughout the entire composting mass, though some zones may never have reached 55 8C for the specified amount of time (Gerba et al 1995;Guardabassi et al 2003;Salter and Cuyler 2003). In other words, temperature monitoring and (or) reporting may falsely give the impression that the time-temperature criteria have been met throughout the entire composting mass, though some zones may never have reached 55 8C for the specified amount of time (Gerba et al 1995;Guardabassi et al 2003;Salter and Cuyler 2003).…”