Dual system of water safety plan auditing in Hungary: benefits and lessons learnt.

A risk-based approach is recognised worldwide as the most reliable means for the provision of safe drinking water. Efficient implementation of the water safety plan (WSP) approach, recommended by the World Health Organization (WHO), is facilitated by an auditing framework. In Hungary, development of WSPs is a legal obligation for water suppliers. WSPs are subject to a two-stage regulatory audit, a consultative central technical audit and a formal local audit. In 2019, a survey was conducted in cooperation with WHO to evaluate audit experiences of over 1,200 WSPs. Recommendations from the central audit significantly improved coherence and compliance of WSPs, confirming the efficiency of the dual approach. The use of a WSP template provided by the national authority further increased consistency and reduced time and work demand of the audit. Both water suppliers and public health authorities indicated a need for further capacity building on WSP development and auditing. The main challenge for water suppliers is the identification and risk assessment of hazards associated with the water source and distribution within premises. The recast European Union drinking water regulation is expected to accelerate the uptake of WSP and strengthen linkages to water catchment management and water safety in buildings.

Investigation of the association between lithium levels in drinking water and suicide mortality in Hungary.

BACKGROUND: In recent decades, a series of ecological studies from various countries have attempted to reveal whether there is an association between trace amounts of lithium in drinking water and suicide mortality. With some notable exceptions, results have indicated that there is an inverse association between these two variables. Since Hungary had extremely high rates of suicide with a persistent spatial pattern, we consider that our country is ideal to investigate this research question. METHODS: We carried out our research on Hungarian data at the level of districts (n = 197). The dependent variable was the age- and gender-standardized mortality ratio for suicide (sSMR). Our main explanatory variable was the tap water lithium level (Li) from public drinking water supply systems using their own water source (n = 1 325). Those data, which give full national coverage, were aggregated to the level of districts. Confounding factors were religiosity, alcohol consumption and income. Various regression models were used for statistical calculations. RESULTS: Findings from our most appropriate regression model - adjusted for relevant confounding variables and able to handle spatial autocorrelation and heteroscedasticity - suggest a significant (p < 0.05) and a trend-like (p < 0.1) negative association between Li and sSMR in the total population and among males, respectively. However, such an association was not found between these two variables among females. CONCLUSION: In line with the majority of findings from other countries, our results indicate that the intake of lithium with drinking water may have a gender-dependent suicide-protective effect.

Transient nature of riverbank filtered drinking water supply systems - A new challenge of natural radioactivity assessment.

In Hungary the drinking water supply is mainly based on groundwater, in which radionuclides are common components. Since the mobility of the most common radionuclides, uranium and radium, is strongly influenced by the geochemical conditions, knowledge on the geochemical parameters of water is required. This depends on the flow system and the flow regime. Therefore, hydrogeology has a crucial role in revealing the origin of elevated activity concentrations. This research presents a case study in Hungary where the drinking water supply is provided by bank filtered and karst wells. In most of the wells of the research area the gross alpha values are above the screening level, 0.1 Bq L-1. The aim of this study is to determine which radionuclides may cause the elevated radioactivity and explain their occurrence using the hydrogeological approach. All samples of the study were analysed for (U-238+U-234), Ra-226, Rn-222. Alpha spectrometry applied on Nucfilm discs was used to measure the uranium and radium activity while radon activity was determined by liquid scintillation. The study revealed the correlation between the river water level fluctuation and the uranium content of the wells. The results of this study highlighted the transient nature of river bank filtered systems, which should be taken into account in the monitoring and water supply strategy.

Uranium in groundwater - The importance of hydraulic regime and groundwater flow system's understanding.

Uranium and other natural radionuclides are common components in groundwater, but they are not routinely measured. In drinking water their total activity is screened, but in the evaluation of the measured values usually the aquifer material is only considered. However, the occurrence of radionuclides in groundwater is strongly affected by flow systems and their geochemical characteristics. Therefore hydrogeology and flow system's evaluation is crucial to understand natural radioactivity. Areas of different hydraulic regimes - recharge, throughflow and discharge - even within the same aquifer are characterized by different geochemical environment. In the present study pressure-elevation profiles were generated based on existing basic hydraulic data of wells in order to determine the flow regimes and associated vertical groundwater flow directions. 24-753 mBq L-1 uranium activity concentrations were found in groundwater and surface water showing great areal variability. High uranium values correspond to recharge regimes with downward flow directions. Uranium mobility is enhanced by high bicarbonate content and circumneutral pH. The study emphasize the importance of groundwater flow system's understanding in those areas, where elevated background radioactivity may exist.