The purpose of this study is to find the value of the discharge coefficient (Cd) on a sieve with a circular perforated plate so that it can be used for application in the field. The method used is to make a physical model test of the screen weir in the laboratory with a width of 40 cm and a length of 797 cm, then the screen is made variations in the diameter of the hole 6, 8, 10 and 12 mm, flowrate Q = 453–4 481 cm3∙s–1 and the slope of the screen θ = 20–45°. The result was quite ef-fective, the sediment did not enter above the screen and did not clog the screen even the catch was quite good about 80% of the screen rods. The discharge coefficient (Cd) is directly proportional to the square value of the number Froude (Fr), the slope of the screen (θ) and the ratio of distance, diameter of the screen (a:d) and inversely proportional to the value of the specific energy square (E). From modelling the average value of the discharge coefficient (Cd) between 0.1–2.75 with NSE = 0.71, MAE = 0 and RMSE = 0.12.

The paper characterises the method of estimating the size of the areas supplying radon to radon groundwater intakes. It is presented on the example of the intakes of radon groundwaters and radon acidulous waters of Lądek Zdrój, Świeradów Zdrój and Kowary. The results of appropriate calculations prove that the volume of rocks supplying radon to the groundwaters of particular intakes oscillates from over ten to several hundred thousand cubic metres. Considering the depth of the zone where radon saturation of these waters takes place, the area supplying this gas to particular intakes varies from several hundred to several thousand square metres. The largest areas of radon-222 supply are characteristic of the most discharge springs, while the smallest ones belong to the springs of low discharge, especially the intakes of groundwater mixture, where only one component supplies large quantities of radon-222. The recharge areas of groundwaters in which

Fine particulate matter ( PM) air pollution is one of the main environmental health problems in developed countries. According to modeling estimates the PM,, concentrations in Poland arc among the highest in Europe. In this article we focus on exposure assessment and estimation of adverse health effects due to PM, air pollution. This art i ck consists of two parts. The first part, we discuss the main methods used to estimate emission-exposure relationships and adverse health effects due to PM, air pollution. In the second part, we present an assessment framwork for Poland. We illustrate this framework by estimating the premature deaths and change in life expectancy in Poland caused by anthropogenic. primary PM,, emissions from different European countries, and, in proportion. the premature deaths in different European countries caused by primary PM,, emissions from Poland. The PM,, emissions were evaluated using the inventory of the European Monitoring and Evaluation Programme (EMEP). The emission-exposure relationships were based on the previously published study and the exposure-response functions for PM,, air pollution were estimated in expert elicitation study performed lor six European experts on air pollution health effects. Based on the assessment. the anthropogenic primary PM, from the whole or Europe is estimated to cause several thousands of premature deaths in Poland, annually. These premature deaths arc both due to PM, emissions from Poland and transportation of PM,, from other European countries. both of these in almost equal parts. The framework presented in this article will be developed in the near future to a full scale integrated assessment. that takes into account both gaseous and PM air pollution.