Hard Water, More Elastic Arteries: A Case Study from Krupina District, Slovakia

Impact of drinking water hardness on carotid atherosclerosis and arterial stiffness: Insights from the "Corinthia" study

BACKGROUND

Several investigations have highlighted the role of water quality in cardiovascular health. In the present study, we have investigated the effects of drinking water hardness on atherosclerotic burden in carotid arteries and arterial stiffness.

METHODS

"Corinthia" study was conducted in the homonym region in Greece from 2015 to 2017. Carotid atherosclerosis was assessed by intima-media thickness (IMT). Pulse wave velocity (PWV) was used to evaluate arterial stiffness. Tap-water samples were collected from the study area and analyzed for a variety of elements, as well as pH and total hardness.

RESULTS

Individuals living in lower drinking water hardness areas (Area 1) versus individuals living in higher water hardness areas (Area 2) had lower max IMT (p = 0.004) and were less susceptible to carotid plaque formation (p = 0.004). Interestingly, individuals over 65 years from Area 1 had lower mean IMT, max IMT, and less plaque formation (p < 0.001 for all). The mean value of PWV in the overall study population was below the 10 m/s cutoff, which defines arterial stiffness (9.15 ± 2.79 m/s). Nevertheless, a marginally higher rate of vascular stiffening was noted in Area 2 vs. Area 1 (16.2% and 12.8%, respectively, p = 0.048).

CONCLUSIONS

According to this cross-sectional study's findings, a positive association between extra hard water and carotid atherosclerotic burden was found. However, the association with arterial stiffness is unclear and should be investigated further.

Enrichment of drinking water with Ca and Mg by a fluidized bed recarbonization reactor: a case study of Devičie, Slovak Republic

A low content of Ca and Mg in drinking water causes increased health risks. To increase the Ca and Mg contents in the drinking water supplied to the inhabitants of the village of Devičie, a prototype of a fluidized bed recarbonization reactor (RRF) was proposed and tested. A half-burnt dolomite (HBD) was used for the recarbonization. In the RRF, the HBD is kept in buoyancy with the help of water circulation. The capacity of the circulation pump is up to 5 m³ h^-1 and the volume of discharged concentrate, which is added directly to the water source, is up to 0.2 m³ h^-1. The volume of water circulated between the reactor and the circulating tank is many times higher than the volume of discharged water. In 24 h, the Ca and Mg contents stabilized at an equilibrium value of 80 mg L^-1 for Ca and 120 mg L^-1 for Mg, which corresponded to the equilibrium of formation and removal of ions from the system. The concentrate was diluted with the water in the reservoir at a ratio of 1:10, and it achieved the desired increase in Mg and Ca contents by more than 10 and 6 mg L^-1, respectively.

Differences in health status of Slovak municipalities supplied with drinking water of different hardness values

This epidemiological study of ecological type deals with the analysis of relationship between drinking water hardness and health status of inhabitants of the Slovak Republic. This relationship was investigated in two groups of more than 50,000 inhabitants living in 53 different municipalities. The first group was supplied with drinking water with low hardness, and the second group was supplied with drinking water with increased hardness. The health status of the population of both groups was monitored by means of health indicators, which represented 15-year average values, for 1994-2008. We investigated four major causes of death, namely cardiovascular, oncological, gastrointestinal and respiratory tract mortality, and evaluated the average life expectancy. The health status of inhabitants supplied with drinking water with increased hardness was significantly better than the health status of people supplied with drinking water with low hardness. For example, the relative mortality for cardiovascular diseases, oncological diseases, digestive tract diseases and respiratory diseases was 56%, 62%, 128% and 121% higher in the population supplied with soft drinking water compared to the population supplied with hard water, respectively. In addition, life expectancy was more than 4.5 years higher in the population supplied with hard drinking water. Our observation confirms the findings of previous studies on relationship between the water hardness and human health.

Proposal of New Health Risk Assessment Method for Deficient Essential Elements in Drinking Water-Case Study of the Slovak Republic

The US EPA health risk assessment method is currently widely used to assess human health risks for many environmental constituents. It is used for risk assessment from the exposure to various contaminants exceeding tolerable or safe reference doses, determined e.g., for drinking water, soil, air and food. It accepts widely that excess contents of non-essential elements (e.g., As, Pb or Sb) in environmental compartments represent a general risk to human health. However, contrary to toxic trace elements, deficient contents of essential (biogenic) elements e.g., F, I, Se, Zn, Fe, Ca or Mg may represent even higher health risk. Therefore, we propose to extend the human health risk assessment by calculating the health risk for deficient content and intake of essential elements, and to introduce the terms Average Daily Missing Dose (ADMD), Average Daily Required Dose (ADRD) and Average Daily Accepted Dose (ADAD). We propose the following equation to calculate the Hazard Quotient (HQ) of health risk from deficient elements: HQd = ADRD/ADAD. At present, there are no reference concentrations or doses of essential elements in each environmental compartment in world databases (Integrated Risk Information System IRIS, The Risk Assessment Information System RAIS). ADRD and ADMD can be derived from different regulatory standards or guidelines (if they exist) or calculated from actual regional data on the state of population health and content of essential elements in the environment, e.g., in groundwater or soil. This methodology was elaborated and tested on inhabitants of the Slovak Republic supplied with soft drinking water with an average Mg content of 5.66 mg·L-1. The calculated ADMD of Mg for these inhabitants is 0.314 mg·kg-1·day-1 and HQd is equal to 2.94, indicating medium risk of chronic diseases. This method extending traditional health risk assessment is the first attempt to quantify deficient content of essential elements in drinking water. It still has some limitations but also has potential to be further developed and refined through its testing in other countries.

The Hardness of Drinking Water Negatively while Socio-Economic Deprivation Positively Correlate with the Age-Adjusted Mortality Rates due to Cardiovascular Diseases in Hungarian Wine Regions

We compared the age-adjusted death rates (AADR) for cardiovascular diseases (CVD) among 206,159 inhabitants analyzed between 2000 and 2010 in four wine territories of Hungary: Tokaj (white wines), Eger (mostly red wines), Balaton (mostly white wines), Szekszárd-Villány (mostly red wines) and Hódmezővásárhely (HMV) (not a wine region). The mortality rates were also assessed from the aspects of total hardness of drinking water and index of socio-economic deprivation (ID). We found the highest cardiovascular mortality in the Tokaj region and HMV. On the other hand, lower numbers of CVD were observed in Szekszárd-Villány, Balaton and Eger. These findings on cardiovascular mortality correlated negatively and significantly with the values of total hardness of drinking waters, which were low in Tokaj and HMV. They were higher in Szekszárd-Villány, Balaton and Eger. Additionally, and surprisingly, the mortality of CVD correlated positively and significantly with the ID values despite of the small numeric differences. The hardness of drinking water and the level of socio-economic state seem to have a greater impact on the mortality rate of CVD than the consumption of “red” or “white” dominant types of wines at a region. This study shows data on a population larger than 200,000 persons.