Assessment of spa mineral water quality from Vrnjačka Banja, Serbia: geochemical, bacteriological, and health risk aspects.

The goal of this study is to evaluate the quality of seven natural mineral water sources in the Vrnjačka Banja area used in the treatment of various diseases. The 24 macro- and microelements were determined by inductively coupled plasma optical emission spectrometry (ICP-OES). The results show that element content was within allowed limits of concentration, except for B, As, and Se. The evaluated content of these elements can be associated with geological and anthropogenic factors. The sample S6 contains more than twice the concentration of As, meaning that the use of water from this source should be limited due to the negative impact of this element on human health. The calculated values of weekly (EWI) and oral (OI) intakes as well as the acute hazard quotient (HQA) of selected toxic and potentially toxic elements indicate no health risks to the consumers. The highest hazard quotient (HQL) observed for As in sample S6 (2.0·10-1) demonstrated a significant risk of carcinogenic diseases in long-term consumption from this source. The estimated non-carcinogenic (DIA) and carcinogenic (DIL) dermal intakes with acute (HQA) and long-term (HQL) hazard quotient values for sample S3 show that there is no health risk to those who use the water from this thermal source for bathing. The presence of aerobic mesophilic bacteria at 22 °C and 37 °C in samples S3, S6, and S7 as well as sulphite-reducing Clostridia species in sample S5 were detected, potentially indicating some non-faecal or faecal contamination.