The risk to human health related to disposal of animal wastes to soil — microbiological and parasitical aspects

The study was conducted to investigate the microbiological and parasitical risk related to the disposal of animal manure to soil by storage of raw pig slurry at temperatures 4 °C, 20 °C and 42 °C for 115 days. Plate counts of Salmonella typhimurium and number of devitalized non-embryonated model Ascaris suum eggs were determined on days 0, 7, 12, 22, 32, 40, 55, 90 and 115 of storage. At the same intervals level of selected physico-chemical parameters were determined. Microbiological examination showed that S. typhimurium survived in the slurry for less than 115 days at 4 °C and less than 90 days at 20 °C and 42 °C. Devitalization of A. suum eggs increased with temperature and time of storage, but complete devitalization was not achieved even after 115 days at 42 °C. Physico-chemical parameters showed changes related to decomposition processes, but did not allow us to draw definite conclusion regarding their influence on devitalization of pathogens. The results indicate potential risk to human food chain that can be prevented by strict observation of legislative provisions and appropriate treatment of animal manure.