Excess nitrogen (N) deposition and gaseous N emissions from industrial, domestic, and agricultural sources have led to increased nitrate leaching, the loss of biological diversity, and has affected ...carbon (C) sequestration in forest ecosystems. Nitrate leaching affects the purity of karst water resources, which contribute around 50% to Austria’s drinking water supply. Here we present an evaluation of the drivers of dissolved inorganic N (DIN) concentrations and fluxes from a karst catchment in the Austrian Alps (LTER Zöbelboden) from 27 years of records. In addition, a hydrological model was used together with climatic scenario data to predict expected future runoff dynamics. The study area was exposed to increasing N deposition during the 20th century (up to 30 to 35 kg N ha−1 y−1), which are still at levels of 25.5 ± 3.6 and 19.9 ± 4.2 kg N ha−1 y−1 in the spruce and the mixed deciduous forests, respectively. Albeit N deposition was close to or exceeded critical loads for several decades, 70–83% of the inorganic N retained in the catchment from 2000 to 2018, and NO3- concentrations in the runoff stayed <10 mg L−1 unless high-flow events occurred or forest stand-replacing disturbances. We identified tree growth as the main sink for inorganic N, which might together with lower runoff, increase retention of only weakly decreasing N deposition in the future. However, since recurring forest stand-replacement is predicted in the future as a result of a combination of climatically driven disturbance agents, pulses of elevated nitrate concentrations in the catchment runoff will likely add to groundwater pollution.
Endocrine disrupting chemicals (EDCs) can cause adverse effects in individuals and their offspring. In 2017 and 2018, we performed a survey on representative samples of Austrian drinking water (n = ...20), groundwater (n = 22), and surface water (n = 12), the latter including bathing water (n = 5) and rivers (n = 7). We analyzed 54 samples for 28 parameters, including estrogens, polybrominated diphenylethers (PBDEs), phthalates, perfluoroalkyl substances, alkylphenols, bisphenol A and triclosan, correlating to 1512 measurements. In 39 of the 54 samples (72.2%), at least one endocrine disrupting or potentially disrupting chemical was found at or above the limit of quantification. None of the samples yielded estrogens or triclosan in detectable levels. Bisphenol A (BPA) was detected in 4 (20.0%) samples of drinking water, in 1 (4.5%) groundwater sample, and in 1 (20%) bathing water sample, with a maximum concentration of 0.021 μg/l found in one drinking water. Two drinking water samples yielded BPA in concentrations above the limit value of 0.01 μg/l, recently proposed by the European Commission for drinking water. Therefore, the ultimate public health goal must be to further reduce and restrict the production of EDCs and therewith decrease and eventually eliminate the contamination of drinking water resources.
We surveyed antibiotics in drinking water in Austria. Testing for 37 antimicrobials was performed by online solid-phase extraction–liquid chromatography–high-resolution mass spectroscopy method. ...Selection of sample sites for drinking water resources focused on areas considered susceptible to contamination and on geographic population distribution. Sulfamethoxazole was detected in 10 (5%) of 200 samples collected in 2014. Five samples showed concentrations above the limit of quantification (2.5 ng/l). Concentrations measured were ≤8.9 ng/l, making toxic effects highly unlikely. However, even low-level concentrations of antibiotics could increase bacterial resistance. The presence of antibiotics is presently not regulated. We assume anthropogenic pollution (not animal husbandry) as source and ask for a maximum permissible value of antibiotics in drinking water.
For water management purposes, information about an entire aquifer system is generally more important than information about a specific spring. Since a karstic aquifer system might drain to several ...outlets, conclusions derived from a single spring can be misleading for characterization and modeling. In this study we apply a conceptual model to an Alpine dolomite karst system in Austria. The particular challenge was that several small springs with strongly varying hydrological behavior and diffuse flow into surrounding streams drain this system. Instead of applying the model to a single spring, it was calibrated simultaneously to several observations within the system aiming to identify the karst system’s intrinsic hydrodynamic parameters. Parameter identification is supported by modeling the transport of water isotopes (δ18O). The parameters were transferred to the whole system with a simple upscaling procedure and a sensitivity analysis was performed to unfold influence of isotopic information on parameter sensitivity and simulation uncertainty. The results show that it is possible to identify system intrinsic parameters. But the sensitivity analysis revealed that some are hardly identifiable. Only by considering uncertainty reasonable predictions can be provided for the whole system. Including isotopic information increases the sensitivity of some intrinsic parameters, but it goes along with a sensitivity decrease for others. However, a possible reduction of prediction uncertainty by isotopic information is compensated by deficiencies in the transport modeling routines.
Application of passive samplers is demonstrated for assessment of temporal and spatial trends of dissolved polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and priority ...metals in the middle stretch of the Danube river. Free dissolved concentrations of PAHs, measured using SPMD samplers, ranged from 5 to 72 ng L−1. Dissolved PCBs in water were very low and they ranged from 5 to 16 pg L−1. Concentration of mercury, cadmium, lead and nickel, measured using DGT samplers, were relatively constant along the monitored Danube stretch and in the range <0.1, <1–20, 18–74, and 173–544 ng L−1, respectively. Concentrations of PAHs decreased with increasing temperature, which reflects the seasonality in emissions to water. This has an implication for the design of future monitoring programs aimed at assessment of long term trends. For such analysis time series should be constructed of data from samples collected always in the same season of the year.
•Seasonal and spatial dynamics of waterborne priority pollutants was assessed in the Danube river.•Dissolved concentrations of contaminants in water column were measured using passive samplers.•The small spatial and temporal contaminant variability is related to diffusive pollution sources.•Seasonality of aqueous concentrations of PAHs reflects the atmospheric deposition.•Passive samplers are a useful tool for monitoring seasonal and spatial trends of priority pollutants.
The study demonstrates the applicability of passive samplers for effective monitoring of seasonal and spatial trends of free dissolved waterborne priority pollutants in a large European river.
The impact of air pollution is a substantial European and global problem which has been observed even in the most remote areas of our planet. Not only surface water, but also groundwater resources ...are partly endangered by dry and wet deposition from the air. Karst and other sensitive aquifers contribute up to 90 % to the total drinking water supply in some European regions. However, they are more vulnerable to contamination than other aquifers due to short transfer times from recharge to source. Therefore, the main objective of this paper is to show possibilities to quantify the impact of air pollution on sensitive water resources （e.g. karst）, to develop an innovative surveillance tool based on isotopes and meteorological considerations. Comparisons of lead isotope measurements in precipitation, spring waters, soil profiles and dolomite bedrock in a relatively pristine and remote area at the front-range of the Northern Calcareous Alps in Austria with literature data indicate that radiogenic Australian gasoline-lead still dominates with 60%-80% the composition of the trace lead in the spring waters. In addition to the lead leached from the dolomite bedrock a third source contributes about 5%-10%. This second long distance Pb-contribution may originate from coal burning and/or Ag-Pb-ore smelting in central Europe in the past. The monthly precipitation （May and September 2005） samples show ^18O-rich sulphate ions, whereas the soil sulphates change in the direction to lower ^18O- and higher ^34S values with depth. The spring waters and bedrock dolomites show relatively low delta ^34S values （4‰-9 ‰）. Assuming the precipitation samples and the dolomite bed rocks are end-members the contribution of atmospheric sulphate can estimated to be 20% in the spring waters and between 10% to 45% in the soil samples. The ^87Sr/^86Sr-isotope results in the precipitation （0.7092） support at least a more radiogeradiogenic, far transported source in addition to a possible recycling of local dolomite and limestone （0.7080-0.7083） dust.
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