Microbiological content and health effect of fishponds enriched with wastewater effluent

During July to December 1980, a study was carried out on kibbutzim (cooperative agricultural settlements) in Israel, to determine the microbiological quality and health effect of fishponds enriched with human wastewater. Ponds on seven kibbutzim were sampled, two of which were chosen for intensive study: one (B231) used domestic wastewater effluent as a fish pond supplement, while the other (C252) used only animal wastes as a supplement. Thirty-eight (38) water samples were assayed for total and fecal coliform. The use of wastewater in the ponds did not consistently increase the levels of the indicator bacteria, in comparison with unenriched ponds. Fish were assayed for coliform and fecal coliform levels in their intestinal tracts and muscle tissue. No consistent difference was found as a result of wastewater enrichment. Salmonella strains were isolated from ponds or fish not exposed to human wastewater, while enteroviruses (poliovirus) were isolated from water from a pond enriched with human wastewater. Analysis of morbidity data showed no significant excess in enteric disease rates among the total population or among fishpond workers on kibbutzim using wastewater for fishpond enrichment, in comparison with kibbutzim not using human wastewater in their fishpond.