The aim of the paper is to compare nitrate concentrations in samples of supply water as well as water from deep and dug wells located in the eastern region of Poland. Additionally, samples of bottled water (spring and natural mineral), certifi ed by the Institute of Mother and Child and the Children’s Memorial Health Institute, were subjected to analyses. On the basis of the obtained results, health risks related to the occurrence of methemoglobinemia in neonates and infants were evaluated. The risk analysis was performed according to the procedure recommended by the United States Environmental Protection Agency. Nitrate concentrations in the examined samples ranged from: 0.153–161.1 mg/l. The lowest concentration of nitrates was determined in the samples of bottled water, the highest being detected in the water from dug wells. It was found that nitrate concentration in samples of bottled and supply water did not pose any risk to the health of neonates and infants. The highest health risk related to methemoglobinemia occurs for neonates consuming water originating from dug wells. The risk decreases along with the age of an infant.
Uranium concentrations in groundwater taken from private drilled wells have been never determined in Poland, implying a lack of available data to quantify the human exposure to U through drinking water consumption, especially in rural areas influenced by mining activities. The main aim of the study was the assessment of human health risk related to the consumption of well waters containing U, collected from selected rural areas of the Lower Silesian region (Poland). The random daytime (RDT) sampling method was applied to the collection of well waters from three control study areas (CSA): Mniszków (CSA-A), Stara Kamienica/M. Kamienica/Kopaniec (CSA-B) and Kletno (CSA-C). The analyses of RDT samples were performed by validated method based on inductively coupled plasma mass spectrometry (ICP-MS). Uranium concentration ranges in well waters and the estimated geometric means for individual control study areas were: 0.005-1.03 μg/L and 0.052 μg/L (CSA-A), 0.027-10.6 μg/L and 0.40 μg/L (CSA-B), and 0.006-27.1 μg/L and 0.38 μg/L (CSA-C). The average and individual chronic daily intakes (CDI) of U by drinking water pathway (adults/children) were in the ranges of: 0.0017-0.013/0.0052-0.040 μg · kg-1 · day-1 and 0.0002-0.90/0.0005-2.71 μg · kg-1 · day-1. The average %TDI and ranges of individual %TDI (adults/children) were: 0.17%/0.52% and 0.02-3.4%/0.05-10.3% (CSA-A), 1.3%/4.0% and 0.09-35%/0.27-106% (CSA-B), and 1.3%/3.8% and 0.02-90%/0.06-271% (CSA-C). The estimated average CDI values of U through well water are significantly lower than the TDI (1 μg · kg-1 · day-1), while for individual CDI values the contribution to the TDI can reach even 90% (adults) and 271% (children), indicating essential human health risk for children consuming well water from private drilled wells located in CSA-B and CSA-C (5.3% of total number of samples collected).