## 1 Introduction
This compound has the ability to form both organic and inorganic aerosols, which can increase the amount of dust in the air [29]. Meteorological conditions for waste collection, storage and processing also have a significant impact from the point of view of odour emission [21]. The literature review has shown that the relationship between these factors is not yet well understood. The results of researches published so far do not give a clear answer on the relationship between meteorological and ambient conditions, odorant concentrations, odour concentrations and waste treatment, because most often they were carried out in a short period of time, or the scientists did not examine all the parameters at the same time. Knowledge of the effect of the above factors will permit the application of efficient operation measures, minimising the odour nuisance of the installations for areas close to the plants. The most important elements influencing the changes taking place in the pollution cloud over the areas of waste management facilities are: the degree of vertical air stability, wind direction and speed, the character of air turbulence and precipitation. In addition, the temperature and humidity of the air, the presence and possibility of precipitation, as well as the pressure and degree of cloudiness must also be taken into account [30; 31]. An increase in wind speed causes a decrease in the concentration of components in a cloud of pollutants. Therefore, the wind speed parameter has a positive influence on the decrease of pollutant concentration. The highest concentrations of pollutants are observed in the lowest ground level air layer. As the distance from the emission source increases, concentrations in the upper atmosphere layers increase and decrease in the lower layers [32]. The contaminants have the ability to shift in the atmospheric layer together with the surrounding air masses, adopting a speed equal to the wind speed. Precipitation and humidity of atmospheric air also affect the range of the cloud of pollutants. The occurrence of rain reduces the concentration of pollutants due to the phenomenon of absorption on the surface of drops. High summer temperatures result in higher odour emissions from surface sources. Fragrance emissions increase during the summer not only due to increased variability, but also due to the increase in anaerobic activity of the bacteria. In addition, oxygen is less soluble at higher temperatures, so the conditions usually become anaerobic. Although high summer temperatures cause higher odorant emissions from open sources, unstable weather conditions during this period tend to disperse pollutants easily. In winter, the situation is reversed. At lower temperatures, emissions are lower, but often also less dispersed due to stable weather conditions [33; 34]. [PERSON] et al. [35] carried out research in Poland around three various sources of odour nuisance (one of the analysed sources was related to waste management) in the six-month period from January to June. They conclude that the biggest odour concentrations around each of the analysed sources were observed in the summer months. In terms of their location, the biggest odour concentrations occurred in the vicinity of the municipal landfill. This research shows that values of mean odour concentration decrease with an increase in relative air humidity in the surroundings, which may result from the phenomenon of sorption of odour compounds on the surface and within the droplets of water mist, bringing about a decrease in the odour concentration in the surrounding air. [PERSON] and [PERSON] [36] conducted similar research and obtained similar results. This paper presents the results of a pilot study conducted at six biogas plants processing municipal waste.