Stability of Major Geogenic Cations in Drinking Water-An Issue of Public Health Importance: A Danish Study, 1980⁻2017

Perspectives on environment and health research in Denmark

AIMS

We provide an overview of nationwide environmental data available for Denmark and its linkage potentials to individual-level records with the aim of promoting research on the potential impact of the local surrounding environment on human health.

BACKGROUND

Researchers in Denmark have unique opportunities for conducting large population-based studies treating the entire Danish population as one big, open and dynamic cohort based on nationally complete population and health registries. So far, most research in this area has utilised individual- and family-level information to study the clustering of disease in families, comorbidities, risk of, and prognosis after, disease onset, and social gradients in disease risk. Linking environmental data in time and space to individuals enables novel possibilities for studying the health effects of the social, built and physical environment.

METHODS

We describe the possible linkage between individuals and their local surrounding environment to establish the exposome - that is, the total environmental exposure of an individual over their life course.

CONCLUSIONS

The currently available nationwide longitudinal environmental data in Denmark constitutes a valuable and globally rare asset that can help explore the impact of the exposome on human health.

Graphene oxide classification and standardization

There is a need to classify and standardize graphene-related materials giving the growing use of this materials industrially. One of the most used and more difficult to classify is graphene oxide (GO). Inconsistent definitions of GO, closely relating it to graphene, are found in the literature and industrial brochures. Hence, although they have very different physicochemical properties and industrial applications, commonly used classifications of graphene and GO definitions are not substantial. Consequently, the lack of regulation and standardization create trust issues among sellers and buyers that impede industrial development and progress. With that in mind, this study offers a critical assessment of 34 commercially available GOs, characterized using a systematic and reliable protocol for accessing their quality. We establish correlations between GO physicochemical properties and its applications leading to rationale for its classification.

Magnesium Administration in Chronic Kidney Disease

Awareness of the clinical relevance of magnesium in medicine has increased over the last years, especially for people with chronic kidney disease (CKD), due to magnesium's role in vascular calcification and mineral metabolism. The inverse association between serum magnesium and clinically relevant, adverse outcomes is well-established in people with CKD. Subsequent intervention studies have focused on the effect of magnesium administration, mainly in relation to cardiovascular diseases, mineral bone metabolism, and other metabolic parameters. The most commonly used routes of magnesium administration are orally and by increasing dialysate magnesium. Several oral magnesium formulations are available and the daily dosage of elemental magnesium varies highly between studies, causing considerable heterogeneity. Although data are still limited, several clinical studies demonstrated that magnesium administration could improve parameters of vascular function and calcification and mineral metabolism in people with CKD. Current clinical research has shown that magnesium administration in people with CKD is safe, without concerns for severe hypermagnesemia or negative interference with bone metabolism. It should be noted that there are several ongoing magnesium intervention studies that will contribute to the increasing knowledge on the potential of magnesium administration in people with CKD.

Spatiotemporal assessment of potentially toxic elements in sediments and roadside soil samples and associated ecological risk in Ropar wetland and its environs

Sediments from banks of the Sutlej River and roadside soils from vicinity of Ropar wetland (collected during pre- and post-monsoon seasons, 2013) were analysed to determine the spatiotemporal distribution of potentially toxic elements (PTEs, viz. arsenic, cadmium, cobalt, chromium, copper, iron, manganese, lead and zinc), which when present in high concentrations may pose health hazards and ecological risk. Contamination factor, degree of contamination, modified degree of contamination, metal pollution index, pollution load index, enrichment factor, geoaccumulation index and ecological risk index were also determined for these PTEs in the study area. Sediment and soil samples were found to be alkaline and non-saline (pH > 7.0; EC < 4500 μS cm^-1) with sodium and potassium as major ions. Iron (mg kg^-1) was found to be most abundant in sediments (1477.59-6512.45) and soils (922.64-12,455.00). Cadmium content in sediments exceeded the threshold value (0.99 mg kg^-1) at 2 (pre-monsoon) and 3 (post-monsoon) sampling sites. In both seasons, cadmium (0.10-2.05) and cobalt (11.40-17.52) contents (mg kg^-1) exceeded the threshold limits (0.06 and 8.00 respectively) in all roadside soils. Significant spatiotemporal variation (p ≤ 0.05) was observed for pH; EC; and calcium, magnesium, copper, iron and zinc contents. Low to moderate potential ecological risk was observed for both roadside soils (31.80-213.82) and sediments (41.47-236.73). Contamination factor, enrichment factor and geoaccumulation index for cadmium were highest in roadside soils (6.84, 46.91 and 2.19, respectively) and sediments (7.64, 167.46 and 2.35, respectively) due to settlement of coal fly ash released from the industrial setups, on sediments/soils of the study area.

Drinking water magnesium and cardiovascular mortality: A cohort study in Denmark, 2005-2016

INTRODUCTION

Cardiovascular diseases are globally a major cause of death. Magnesium deficiency is associated with several diseases including cardiovascular diseases.

OBJECTIVE

To examine if a low concentration of magnesium in drinking water is associated with increased cardiovascular mortality and mortality due to acute myocardial infarction and stroke.

METHODS

A nationwide population-based cohort study using national health registries was used. A total of 4,274,132 individuals aged 30 years or more were included. Magnesium concentration in drinking water was estimated by linkage of residential addresses in the period 2005-2016 with the national drinking water quality monitoring database. The association between magnesium concentration in drinking water and cardiovascular mortality and mortality due to acute myocardial infarction and stroke was examined using a Poisson regression of number of deaths and logarithmic transformation of follow-up time as offset. The incidence rate ratio (IRR) was adjusted for differences in age, sex, calendar year, cohabitation, country of origin, and socioeconomic status.

RESULTS

Median magnesium concentration in drinking water at inclusion was 12.4 mg/L (range: 1.37-54.2 mg/L). The adjusted IRR for cardiovascular mortality was 0.96 (95% CI: 0.94; 0.97) for the lowest magnesium quintile (<6.5 mg/L) as compared to the highest magnesium quintile (>21.9 mg/L). The adjusted IRR for mortality due to acute myocardial infarction and stroke was 1.22 (1.17; 1.27) and 0.96 (0.93; 0.99), respectively, for the lowest magnesium quintile as compared to the highest quintile A decreasing mortality due to acute myocardial infarction was seen with an increasing magnesium concentration in a dose-response manner.

CONCLUSION

Low concentrations of magnesium in drinking water were associated with an increased mortality due to acute myocardial infarction. Low concentrations of magnesium in drinking water were associated with decreased cardiovascular mortality, and mortality due to stroke.

Geographical Distribution and Pattern of Pesticides in Danish Drinking Water 2002-2018: Reducing Data Complexity

Pesticides are a large and heterogenous group of chemicals with a complex geographic distribution in the environment. The purpose of this study was to explore the geographic distribution of pesticides in Danish drinking water and identify potential patterns in the grouping of pesticides. Our data included 899,169 analyses of 167 pesticides and metabolites, of which 55 were identified above the detection limit. Pesticide patterns were defined by (1) pesticide groups based on chemical structure and pesticide-metabolite relations and (2) an exploratory factor analysis identifying underlying patterns of related pesticides within waterworks. The geographic distribution was evaluated by mapping the pesticide categories for groups and factor components, namely those detected, quantified, above quality standards, and not analysed. We identified five and seven factor components for the periods 2002-2011 and 2012-2018, respectively. In total, 16 pesticide groups were identified, of which six were representative in space and time with regards to the number of waterworks and analyses, namely benzothiazinone, benzonitriles, organophosphates, phenoxy herbicides, triazines, and triazinones. Pesticide mapping identified areas where multiple pesticides were detected, indicating areas with a higher pesticide burden. The results contribute to a better understanding of the pesticide pattern in Danish drinking water and may contribute to exposure assessments for future epidemiological studies.

Association between magnesium in drinking water and atrial fibrillation incidence: a nationwide population-based cohort study, 2002-2015

BACKGROUND

Atrial fibrillation (AF) is a common heart rhythm disorder and a risk factor of adverse cardiovascular diseases. Established causes do not fully explain the risk of AF and unexplained risk factors might be related to the environment, e.g. magnesium in drinking water. Low magnesium levels in drinking water might be associated with higher risk of cardiovascular diseases including AF. With detailed individual data from nationwide registries and long-term magnesium exposure time series, we had a unique opportunity to investigate the association between magnesium in drinking water and AF.

OBJECTIVE

We evaluated the association between magnesium concentration in drinking water and AF risk.

METHODS

A nationwide register-based cohort study (2002-2015) was used including individuals aged ≥30 years. Addresses were linked with water supply areas (n = 2418) to obtain time-varying drinking water magnesium exposure at each address. Five exposure groups were defined based on a 5-year rolling time-weighted average magnesium concentration. AF incidence rate ratios (IRRs) between exposure groups were calculated using a Poisson regression of incidence rates, adjusted for sex, age, and socioeconomic position. Robustness of results was investigated with different exposure definitions.

RESULTS

The study included 4,264,809 individuals (44,731,694 person-years) whereof 222,998 experienced an incident AF. Magnesium exposure ranged from 0.5 to 62.0 mg/L (mean = 13.9 mg/L). Estimated IRR (95% CI) compared to the referent exposure group (< 5 mg/L) was 0.98 (0.97-1.00) for the second lowest exposure group (5-10 mg/L), and 1.07 (1.05-1.08) for the two highest exposure groups (15-62 mg/L). Strongest positive associations were observed among those aged ≥80 years and with lowest education group. An inverse association was found among individuals with highest education group.

CONCLUSION

There might be a small beneficial effect on AF of an increase in magnesium level in drinking water up to 10 mg/L, though an overall positive association was observed. The unexpected positive association and different associations observed for subgroups suggest a potential influence of unaccounted factors, particularly in vulnerable populations. Future research on magnesium in drinking water and cardiovascular diseases needs to focus on contextual risk factors, especially those potentially correlating with magnesium in drinking water.

Laboratory and pilot evaluation of aquaporin-based forward osmosis membranes for rejection of micropollutants

Aquaporin-based forward osmosis (AQP FO) membranes were applied both in laboratory- and pilot-scale for removing micropollutants from water. The effect of operating parameters (feed flow, draw flow, and transmembrane pressure) on the i) rejection of micropollutants, ii) water flux, iii) reverse salt flux, and iv) water recovery of the AQP FO membrane modules was studied. Among the 21 micropollutants spiked, only four compounds, atenolol, propranolol, metoprolol, and citalopram, permeated through the AQP FO membranes to an extent that they could be quantified in the draw solutions of both the laboratory and pilot systems. The rejection rates, based on the full mass balance calculations, were between 96.1% and 99.7%, and all the other 17 compounds showed rejection exceeding 90% on both systems. The pilot AQP FO system was further employed for six days to treat effluent from a membrane bioreactor (MBR) treating municipal wastewater. 35 micropollutants were investigated. 27 of these were identified and quantified in the MBR effluent. Minute fractions of gabapentin, benzotriazole, and metoprolol were detected passing through the AQP FO membranes into the draw side with a constant rejection of around 99.2%, 95.4%, and 99.9%. Almost all other micropollutants' minimum rejection rates exceeded 80%.

Groundwater quality evaluation using Shannon information theory and human health risk assessment in Yazd province, central plateau of Iran

This study aims to evaluate the quality of groundwater in the most arid province of Iran, Yazd. It is highly dependent on groundwater resources to meet the domestic, industrial, and agricultural water demand. Position of water samples on the modified Gibbs diagram demonstrates that the interaction with silicates and the increase in direct cation exchange are responsible for the increased salinity of groundwater. Based on entropy theory, the decreasing order of importance of variables in controlling groundwater chemistry is Fe > As > Ba > Hg > NO₂ > Pb > K > Cl > Na > Mg > SO₄ > NO₃ > HCO₃ > Ca. The results of entropy weighted water quality index (EWWQI) calculation show that about 34 and 32% of 206 samples in the wet and dry seasons, respectively, are classified as extremely poor quality (ranks 4 and 5). Approximately 60 and 55% of 206 samples in wet and dry seasons, respectively, have excellent, good, and medium quality (ranks 1, 2, and 3). The non-carcinogenic human health risk (NHHR) from intake and dermal contact pathways using deterministic approach show that 36 and 17 samples in both seasons are not suitable for drinking by children. Furthermore, 9 and 2 samples are not suitable for drinking by adults. The results show that children are more vulnerable than adults to these health risks. The non-carcinogenic risks through dermal contact were negligible.

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.

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

The protective role of hard drinking water against cardiovascular diseases is well documented by numerous studies. This article describes the impact of Ca and Mg contents in the drinking water with different water hardness on the cardiovascular system (arterial stiffness, arterial age) of residents of the Krupina district, the Slovak Republic. The research was based on the measurements of arterial stiffness, including the measurements of aortic pulse wave velocity (PWVao) and the calculation of the arterial age of the residents. In total, 144 randomly selected residents were included in measurements, divided into the two groups according to Ca and Mg contents in drinking water (water hardness). The first group was supplied with soft drinking water (total dissolved solids (TDS): 200-300 mg·L^-1, Ca: 20-25 mg·L^-1, Mg: 5-10 mg·L^-1). The second group of residents was supplied with harder drinking water (TDS: 500-600 mg·L^-1, Ca: 80-90 mg·L^-1, Mg: 25-30 mg·L^-1). Differences in arterial stiffness between the two groups of respondents were documented. Higher arterial stiffness (low flexibility of arteries) was determined for a group of residents supplied with soft drinking water. This was reflected in higher PWVao levels, higher number of pathological cases (PWVao > 10 m·s^-1), and arterial age of respondents compared to their actual age. The "absolute" difference between the arterial and actual age between the two evaluated groups of residents (soft vs. harder water) was nearly 5 years on average. The higher arterial stiffness and age of residents that consumed soft drinking water indicate the health significance of lower contents of Ca and Mg in drinking water as an environmental risk factor of cardiovascular diseases. Measuring arterial stiffness of residents in the areas supplied with soft drinking water can be used as a non-invasive approach in the prevention of cardiovascular risks.