We present a preliminary study report on the toxicity of tap water exposed to low-temperature plasma. The report was prepared by dr hab. Teodora M. Traczewska and dr inż. Magdalena Sitarska.

The conducted tests were aimed at determining the biological activity of water exposed to low-temperature plasma with the use of various commercial tests to assess the toxicity and mutagenicity of water, in order to determine the possibility of its impact on the natural environment.

The conclusions of these studies are as follows:

1. Water subjected to plasma does not show mutagenic properties.
2. Plasma water has a beneficial effect on bacteria by stimulating their metabolic processes (increasing luminescence by Vibrio fischeri bacteria).
3. A significant inhibition of the growth of Selenastrum capricornutum algae was found
   in the presence of water subjected to a low-temperature plasma.
4. In the case of monocotyledons, no significant effect on the germination of seeds was observed, but this water had a positive effect on the growth of roots and shoots, increasing their length by up to 40%.
5. The beneficial effect of water treated with the plasma on the growth of roots was observed in relation to all plants used in the tests.
6. In the case of 50% and 30% of the water treated with plasma, their negative effect on the growth of the shoot of dicotyledons was found.
7. Water subjected to plasma inhibits food intake by planktonic organisms present in surface waters, but the degree of inhibition is lower than for tap water.