Radon is the most important of all sources of natural radiation, and it belongs to the main air pollutants in closed space. It is necessary to develop awareness of its harmful effects in buildings in order to take appropriate measures to reduce the risk of exposure to it. This study assesses public awareness of radon-related risks in Serbia by analyzing four areas: general public, legislative framework, professional practices, and student knowledge. Data were collected from media sources, legal documents, conferences and scientific publications, and surveys among students of University of Belgrade. Student answers have shown that they are not aware of the danger of radon in buildings: there is a gap between knowledge about radon and about its effects in the interior space. The results also show low presence of this topic in the media and in professional circles in Serbia. This paper is a contribution to the overall efforts to spread awareness in Serbia about the problem of the presence of radon in closed spaces and the health problems it can cause. This is also important in the context of the search for energy-efficient building solutions, where the passive house is emerging as the most sustainable form. It is a relatively new concept in Serbia, so information about the harmful effects of radon in indoor spaces and about the implementation of certain strategies in passive construction for protection against radon is necessary in order to protect the health of the environment and the population.

The Danube navigation is geographically limited and subject to the effects of environmental change. On the other hand, the Danube commercial navigation is the point source of pollution with emissions of the Danube vessels and harbours, directly polluting the environment. The focus of this paper is the annual evaluation and calculation of air polluting emissions from fossil fuel consumption from the following types of the Danube fleet: push boats, pull boats, freight motor vessels and cruise passenger ships. Emissions from the Danube transport vessels are estimated by EMEP/EEA (European Monitoring and Evaluation Programme/European Environment Agency) air pollutant emission inventory guidebook within Serbian-Croatian, Serbian and Serbian-Romanian sections of the Danube fairway on an average level. Emissions costs for all types of the Danube fleet (euro per vessel-kilometre) are estimated by the Practical guideline for realistic transport pricing depending on the population density close to the waterway: rural or urban area.