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

Abstract

SummaryThe 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.

The Possibility of Contamination of Water-Soil Environment as a Result of the Use of Pig Slurry

“…In turn, Olszewska et al [12] noted that in pig slurry stored for 44 weeks (the same time as in Katakam's research) under laboratory conditions at 4 °C the percentage of invasive eggs of Ascaris suum decreased to a level of 49 %, while in pig slurry stored at 20 °C to 11 %. The study of Kachnic et al [65] also showed that at higher temperatures devitalization of Ascaris suum eggs was increased, however, even after 115 days of raw slurry storage at 42 °C, complete devitalization was not achieved. An excessive fertilizing use of pig slurry in fields and pastures or the application of slurry from sick animals, including asymptomatic ones, can be a source of microbial contamination of soils (due to the impairment of self-purifying ability) and plants, which in turn poses a risk of pathogens infiltrating into the food chain of animals (domestic and wild) and humans [62,64,71].…”

“…Bacteria in pig slurry can survive for many days (Table 2), according to Olszewska and Skowron [64] bacilli of Salmonella Typhimurium are able to survive in the slurry stored in laboratory conditions at 4 °C for about 75 days while at 20 °C their survival time is shorter and amounts 30 days. However, Kachnic et al [65] noted that Salmonella Typhimurium survived in the pig slurry (stored in closed plastic containers) for less than 115 days at 4 °C and less than 90 days at 20 °C and 42 °C. Ajariyakhajorn et al [66] observed that Salmonella Anatum survived in the pig slurry, the pH of which was equal to 7.0, for 56 days at 4 °C.…”

The reduction rate of invasive Ascaris suum eggs number in slurry and humus layers of selected soil types

“…For comparison, in the present experiment this percentage after 6, 10 and 18 weeks was equal to 50 %, 73 % and 61 % at 20 °C and 79 %, 88 % and 79 % at 4 °C, respectively. Kachnič et al (2014) Johnson et al (1998) observed that both temperature and the part of lagoon have the effect on the level of invasive eggs elimination. According to the results of their study in the period between 5 and 25 week of the experiment the percentage of A. suum live eggs in the middle part of the lagoon decreased from 77 % to 11 %, and in the outflow from 68 % to 48 % (Johnson et al, 1998).…”

Pro-Environmental Behaviors: Relationship With Nature Visits, Connectedness to Nature and Physical Activity

“…Men who owned dogs also adopted a greater number of PEBs. Several authors 11,54,55 identified a positive association between these variables and did not differentiate them according to gender.…”