The growing interest in the negative environmental impact of overhead power lines of high and extra-high voltage stems from the increasing ecological awareness of societies. Consequently, a number of respective legal restrictions have been issued and actions have been undertaken to reduce this impact, especially in the electric field of the power frequency. The aim of this paper is to analyze the possibilities of reducing the width of electric field influence zones by changing the design parameters of power lines and defining the spatial distribution of its conductors. This analysis was carried out using the developed and experimentally verified models for determining the electric field and audible noise in the power line environment. The computational models were used to analyze the width of the electric field influence zones of 400 kV lines and the noise levels at the borders of these zones. The research focused on single and double circuit 400 kV power lines. It was revealed that a reduction in electric field emissions is accompanied by an increase in noise emission. However, the analyses confirmed that the width of the electric field influence zones can be significantly reduced if the most important design and construction parameters of the line are properly selected. The obtained conclusions are valid not only for 400 kV lines, but also set directions to follow when changing the parameters of high voltage transmission lines of other rated voltages (above 100 kV).

Wind turbines emit infrasound and low-frequency noise (ILFN), which can be annoying for people living near wind farms. To assess the acoustic impact of wind turbines on the environment, it is essential to model ILFN propagation during the forecasting stage. This study assesses the effectiveness of three commonly used sound propagation models (ISO 9613-2, CNOSSOS-EU for favourable propagation conditions, Nord2000) in predicting ILFN generated by wind turbines. The performance of these models in modelling ILFN is generally not validated or guaranteed. The analysis covers octave frequency bands ranging from 4 Hz to 250 Hz, and comparisons are made against measurements conducted at a wind farm in Poland. Non-parametric statistical tests were used with a significance level of $\alpha =0.05$ to determine significant differences between measured and predicted results. The results show that the Nord2000 method provides accurate calculations, while the ISO 9613-2 method can be used for simplified assessments of ILFN generated by wind turbines during the investment preparation phase.