Assessment of surface and groundwater quality for irrigation purposes in the Danube-Tisa-Danube hydrosystem area (Serbia).

The study evaluates irrigation water quality in the Danube-Tisa-Danube hydrosystem area (Vojvodina, northern Serbia). The area is dominantly a plain with about 75% arable land, suitable for agricultural production and irrigation. Use of water of inadequate quality can have long-term effects on irrigated land and affect the yield of cultivated crops. The analyses included data from 40 surface water and 23 groundwater quality monitoring locations, observed during the period 2013-2018. The average annual values of the concentrations of major cations and anions and of electrical conductivity in surface and groundwater were comparatively analyzed. These values were statistically significantly higher (by p < 0.05) in groundwater bodies with most of the analyzed parameters. Hydrochemical classification of water types shows that 95% of surface and 87% of groundwater locations belong to the Ca·Mg-HCO3 water type. Water suitability for irrigation was assessed using specific parameters and indices (sodium adsorption ratio, Na%, residual sodium carbonate, magnesium hazard, permeability index, and Kelly's index). The results showed that surface and groundwater resources are generally of good quality and suitable for irrigation, with sporadic deviations at several locations. The principal component analysis (PCA) was used to identify the most important variables affecting the chemical composition of the analyzed waters and group the monitoring locations by their chemical characteristics. The spatial variation of the analyzed water quality indices was shown on thematic maps.

Longitudinal distribution of macronutrients in the sediments of Jegricka watercourse in Vojvodina, Serbia.

Sediment matrices, as integral organo-mineral parts of aquatic bodies, can effectively bind and accumulate nutrients and potentially hazardous substances from diffuse and/or point sources of contamination. In this study, we analysed the longitudinal distribution of macronutrients (total N and available P and K) and the mechanical composition of the sediments of Jegricka watercourse (a part of the multi-functional Danube-Tisa-Danube canal network) known for its exposure to anthropogenic loads. The results showed that the nutrient pollution index was mostly above 1.0 (in 76%, 86% and 93% of the analysed samples for K, N and P, respectively), and the mean values for N, P and K were 2.69, 1.92 and 1.24, respectively. The average content of all nutrients and the sand fraction were significantly higher, whereas the clay fraction was considerably lower, in the sediment samples than in the adjacent arable Chernozem soil used as a benchmark. The differences in the nutrient contents and mechanical properties in the sediments were measured longitudinally (at upstream vs. downstream stations) and assessed using correlation, cluster analysis, and principal component analysis. The results suggest that the nutrient sources in the sediments as well as their transport and loading mechanisms along Jegricka watercourse are diverse and complex, likely driven by a combination of untreated industrial/urban wastewater discharges, erosion and surface runoff from the surrounding agricultural land. As a majority of the analysed watercourse banks belong to areas of special ecological value, the obtained results may be useful: i) indicators for designing and implementation of sustainable land/water policies and measures for the protection and rehabilitation of these valuable ecosystems, ii) inputs for testing/calibrating the sediment transport models and iii) the basis for sediment management.

The Association between Drinking Water Quality and Inflammatory Bowel Disease-A Study in Eastern Croatia.

The incidence rate of inflammatory bowel disease (IBD) is becoming a global health problem that could be caused by changes in environmental and lifestyle habits. The study aimed to identify the association between the quality of drinking water, i.e., physiochemical and biological aspects of the phenotype and activity of IBD in Eastern Croatia. The study included 312 patients (63.4% ulcerative colitis, UC, and 36.6% Crohn's disease, CD) from the area of Eastern Croatia. The data were collected by questionnaires and the analysis of the water safety, based on 65 samples of drinking water by the patient's water supply method (public supply, rural water supply, and private well). IBD was active in 38.0% patients (34.0% CD and 40.0% UC). Significant differences (p = 0.001) were observed in the distribution of patients, according to counties in which they lived in. The largest deviation was noted in coliform bacteria, Escherichia coli, and enterococci bacteria, Fe, Al, and nitrate in rural water supply and private wells, although, without significant impact on IBD phenotype and activity. The hazard quotient (HQ) simulations showed that children are a sensitive group, regarding exposure to nitrates in drinking water over a long period of time, so there is a need for further monitoring and analysis of this issue.