Air quality is crucial for human health and welfare. A large number of studies have indicated strong
associations between ambient air pollution levels and adverse health effects. There is a considerable number
of literature reports concerning changes in atmospheric greenhouse emissions, while relatively little is known on
changes in atmospheric CO emissions. This paper presents the rate of changes in atmospheric CO emissions using the
logarithmic method in the assessment of this rate. Studies were conducted based on source data from 32 Organization
for Economic Cooperation and Development countries. Analyses covered the period of 2005–2012. It was found that
the average rate of changes had a negative average rate for most, although not all analyzed countries. In three of the
32 countries atmospheric CO emissions increased in that period. While the intensity of these changes varied, a defi nite
majority of the countries reduced their CO emissions, whereas Turkey, Poland and Estonia increased their emissions.
The paper presents a measuring system based on two resonators with a SAWacoustic surface wave. One of the resonators contains a sensor structure consisting of a Nafion layer with a PANI polyaniline nanolayer deposited on it. The sensor structure was tested for carbon monoxide, with a very low concentration (5, 10, 15, 20 ppm) in the atmosphere of synthetic air. The structure sensitivity was tested for two different PANI thicknesses: (100 and 180 nm). The tests were carried out for two different temperatures: 308 K and 315 K. The investigations shows that the measuring system used with the acoustic surface wave together with the proposed sensing layers is sensitive to the presence of low concentration carbon monoxide molecules in the atmosphere of synthetic air.