[Show abstract][Hide abstract] ABSTRACT: Urban and agricultural areas affect the hydraulic patterns as well as the water quality of receiving drainage systems, especially of catchments smaller than 50 km(2). Urban runoff is prone to contamination due to pollutants like pesticides or pharmaceuticals. Agricultural areas are possible sources of nutrient and herbicide contamination for receiving water bodies. The pollution is derived from leaching by subsurface flow, as well as wash-off and erosion caused by surface runoff. In the Luxembourgish Mess River catchment, the pharmaceutical and pesticide concentrations are comparable with those detected by other authors in different river systems worldwide. Some investigated pesticide concentrations infringe current regulations. The maximum allowable concentration for diuron of 1.8 μg l( - 1) is exceeded fourfold by measured 7.41 μg l( - 1) in a flood event. The load of dissolved pesticides reaching the stream gauge is primarily determined by the amount applied to the surfaces within the catchment area. Storm water runoff from urban areas causes short-lived but high-pollutant concentrations and moderate loads, whereas moderate concentrations and high loads are representative for agricultural inputs to the drainage system. Dissolved herbicides, sulfonamides, tetracyclines, analgesics and hormones can be used as indicators to investigate runoff generation processes, including inputs from anthropogenic sources. The measurements prove that the influence of kinematic wave effects on the relationship between hydrograph and chemographs should not be neglected in smaller basins. The time lag shows that it is not possible to connect analysed substances of defined samples to the corresponding section of the hydrograph.
Environmental Monitoring and Assessment 11/2010; 180(1-4):127-46. · 1.68 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: This investigation focuses on the analysis of four classes of veterinary and human pharmaceuticals in surface water in Luxembourg. The selected pharmaceuticals include four sulfonamides, two tetracyclines, two analgesics, and three hormones. Solid-phase extraction with liquid chromatography-tandem mass spectrometry resulted in detection limits ranging from 0.3 to 2.0 ng/L, allowing the determination of pharmaceuticals in storm waters. The analysis of pharmaceuticals by liquid chromatography-tandem mass spectrometry is a useful tool to trace their behaviour in the aquatic environment. Application of this method to river concentration and flood events revealed high concentrations of ibuprofen, with highest levels during flood events, while concentrations of estrogens and sulfonamides were comparatively low. So far, the yeast estrogen screen has been applied for some of the samples. The measured steroid values were converted to estrogenic activity by taking into account the relative potency of each chemical compared to the reference, estradiol. This method considers the relative affinity of the steroids for the hormone receptor. The measured estrogenic activity in the surface water is regularly at levels larger than 5 ng/L estradiol equivalents which might be of concern to reproductive success of native fish populations. The concentration and transport of xenobiotics in surface waters depend on hydraulic conditions including rainfall pattern and sewage overflow, on the properties of the substances, including sorption, degradation, and metabolism. The analysis of flood events using the rainfall pattern, the hydrograph, and dissolved pharmaceutical chemographs provides an insight into the temporal structure of flood events. The corresponding anthropogenic sources show a high temporal and spatial variability that is caused by different rainfall patterns and distributions, and the different characteristics (e.g. retention capacities) of the combined sewer systems. We can show that the combined sewer overflows deliver an important part of the dissolved pharmaceuticals into the river network.
[Show abstract][Hide abstract] ABSTRACT: The objective of this investigation is to analyse the variations of xenobiotic concentrations and the fluxes of dissolved
xenobiotics during runoff events in the small rural Mess catchment (35km2) in the Southwestern part of Luxembourg. Sulfonamides, tetracyclines, analgesics and hormones, dissolved nutrients, sulphate
and chloride were measured to gather information about runoff generation. Typically, the highest values can be found during
the first flush mainly in the rising limb of the flood hydrographs. The highest concentrations in eleven flood events are
measured for ibuprofen (2,383ng l-1), estrone (27ng l-1) and diclofenac (20ng l-1). From the tetracycline group tetracycline (9ng l-1) itself is of relevance, while the sulfonamides are mainly represented by sulfamethoxazole (5ng l-1). The variable patterns of chemographs are attributed to the heterogeneous runoff generation characterised by different reactions
of storm overflows from the combined sewer systems. During single flood events, the fluxes of ibuprofen (maximum 24,000mg),
17α-ethinylestradiol (122mg), 17β-estradiol (32mg) or estrone (274mg) are rather low.
Water Air and Soil Pollution 203(1):79-98. · 1.75 Impact Factor