Introduction:
Spa residue is an undehydrated therapeutic peat, which belongs to the group of peloids, a natural organic material widely used in spa therapy. Once used for therapy, it cannot be reused due to the loss of adsorptive properties. The aim of the study was the biological and parasitological assessment of spa residue to view the chances for fertilization of soils.

Material and Methods:
In this study 80 samples of spa residues, from 7 spa resorts in Poland were investigated for Salmonella bacteria, bacteria of the general and faecal coliform group, anaerobic sulphites-reducing bacteria of Clostridium perfringens type and the eggs of intestinal nematodes (Ascaris, Trichuris and Toxocara). Microbiological and parasitological analyses of the residue were conducted based on theP olish Standards: PN-Z-19000-1/2001, PN-Z-19000- 4/2001, and Microbiological and Parasitological Guidelines for Sanitary Evaluation of Soils, Institute of Rural Health, Lublin 1995

Results:
In the investigated samples of the residue neither Salmonella bacteria nor the eggs of intestinal nematodes Ascaris, Trichuris or Toxocara were found. The titres of coliform group bacteria, fecal coli bacteria, and Clostridium perfringens bacteria were within the range 1–1012, and did not exceed the limit values set for fertilizers and soils.

Conclusions:
Therefore, it is suggested to reuse spa residue after therapy for agricultural purposes (e.g. soil fertilization).