###### Abstract  
This research examined samples of mineral water available on the Polish market. The contents of radionuclides in 12 samples of water were determined: cesium \({}^{137}\)Cs, thorium \({}^{232}\)Th, potassium \({}^{40}\)K, and radium \({}^{226}\)Ra; and heavy metals: zinc, copper, chromium, nickel, lead, cadmium, and mercury. Spectrometric analysis showed the presence of a \({}^{232}\)Th track in one sample (Franciszek water) with a concentration of 2.4 \(\pm\) 2.1 mBq/L above the LLD (low limit of detection); \({}^{40}\)K potassium was detected in all samples. In the case of radium \({}^{226}\)Ra, its presence above the detection threshold was found in nine water samples. No artificial element \({}^{137}\)Cs was found in the mineral waters. The tests showed the concentrations of heavy metals (Cd, Cr, Cu, Hg, Ni, and Pb) present in the waters. The limit values are specified by the Ministry of Health Regulation. Copper, cadmium, and chromium did not exceed the permissible values. In the case of nickel, the normalized values (20 \(\upmu\)g/L) were exceeded in only two waters: Slotwinka and Jozefowianka. Only in the Amita water did we find that the value of 1.0 \(\upmu\)g/L was exceeded. The concentration of zinc, for which no limit is set in the regulation, was the highest, ranging from 287 to 1.30 \(\upmu\)g/L. The greatest threat to people drinking the studied mineral waters is lead, which in eight waters exceeded the permissible value of 10 \(\upmu\)g/L. radioactive metals; heavy metals; mineral waters +
Footnote †: journal: _Applied_  
waters, soil waters, and shallow groundwater. Water pollution is of particular importance due to the role of water in the circulation of elements in various environments. The concentration of heavy metals in water depends mainly on their chemical properties, including forms of occurrence and solubility [8]. The mobility of these pollutants in water depends on the parameters of the aquatic environment. These include, first of all, the pH, the redox potential, and the ability to form soluble complexes. Water is fit for use if it is free from any substances in concentrations that may pose a risk to human health. In accordance with the Health Minister (2017) ordinance that regulates the requirements for the content of heavy metals in drinking water, metal concentrations should not exceed the following values: cadmium < 5.0 \(\mu\)g/L, copper < 2.0 mg/L, mercury < 1.0 \(\mu\)g/L, nickel < 20 \(\mu\)g/L, and lead < 10 \(\mu\)g/L [9]. Trace metals present in water exist in the form of soluble and insoluble chemical compounds. They bind to solid or colloidal particles and accumulate in sediments and tissues of organisms. Bound metals in the body can reveal toxic properties if they are in an absorbable form at a concentration that causes an adverse reaction by the body. The toxic potential of trace metals to organisms depends on many factors. These are the composition and health of the organisms together with the form, properties, concentration, and availability of the trace metal. Certain trace metals play the role of micronutrients, serving an important role in keeping organisms alive. Trace metals are essential for metabolism. They are supplied mainly with food and water. Elements such as iron and zinc play an important role in the development and functioning of the human body. Additionally, for proper functioning of the body, much smaller amounts of chromium, cobalt, manganese, molybdenum, nickel, selenium, and vanadium are needed [10]. In the body, they perform their function only in certain concentrations. The toxic properties are manifested only when the concentration available to the body exceeds the value necessary to meet the nutritional needs. Toxic concentrations of, e.g., zinc compounds toward plants, aquatic microorganisms, and fish are very low; their toxic value have been determined to be above 0.1 mg/L. Some trace metals play no role in the life cycle of organisms and belong to the group of toxic compounds.