This project initiates a complex study of organic aerosols in rural, urban and marine environment.
Organic matter plays a crucial role in complex biogeochemical processes in aquatic environment. In those processes the reactivity and physico-chemical properties of organic matter are often more important than the amount present. Boundary areas between different environmental compartments represent critical interfaces of special biological, chemical and physical properties. The exchange of matter and energy between water and atmosphere has a decisive role in global changes and in environmental protection.
The interactions between the atmosphere and aquatic systems, the exchange of matter through the air/water interface in particular, are the mechanisms of decisive importance for the fate, transport and cycling of organic matter and other microconstituents in environment. The knowledge available so far shows that the atmospheric input of substances in limnological and marine ecosystems can be dominant on both regional and global scale, and plays an important role in controlling the level and the dynamics of persistent organic pollutants in aquatic systems. Droplets and fine particles suspended in the atmosphere have a crucial role in climate and human health. Aerosol particles affect climate directly via scattering and absorption of radiation and indirectly by affecting properties of clouds and precipitation. Aerosols also affect the human health via inhalation of small size particles.
It was also recently recognized that the organic matter is a major component of atmospheric aerosols. For describing such aerosols the term «organic aerosols» is commonly used. The primary sources of organic aerosol components are vegetation, combustion, biomass burning, sea spray. They can also be formed by photochemical oxidation of ghase phase trace species which yield low vapor pressure oxygenated compounds condensing on airborne particles. From an environmental point of view, a fraction of dissolved organic matter (DOM) which possess surface active properties, may be very important. Surface active substances can influence the condensation processes and the formation of layers around the drops in which some pollutants can be built, which enhances the potential of rain drops for washing out organic matter from the atmosphere and mobilizing micropollutants on the global level. Lipids are also present in aerosols representing useful tracers for source correlation, transport pathways and transformation mechanisms of organic compounds in the atmosphere. Analysis of the compound class distribution in lipids of aerosol particles can give information on the variability of their distribution patterns and on formation and transformation of aerosol particles.
The atmosphere is also one of the major routes by which metal ions enter the aquatic systems. Organic complexation in atmospheric precipitation is an important control mechanism of the biogeochemistry of metal ions. The role of organic complexation is not only in controlling trace metal speciation in rainwater and aerosols, but also in potential to modify metal solubility in precipitation and further on in the aquatic environment. Furthermore, organic-metal complexes may increase the absorbance of cloud droplets and thus modify the radiative transfer of the atmosphere. Many authors studied trace metals presence and distribution in the precipitations and the organic matter composition was studied as well. However, the papers dealing with the interaction between the metal ions and organic matter in aerosols are scarce.
In marine environment an important source of aerosols and cloud condensation nuclei is phytoplankton. Some species of phytoplankton produce dimethyl sulphide (DMS) which entering the atmosphere reacts with other chemicals to form sulphate aerosols which play an important role in climate change. They can directly absorb or scatter sunlight preventing it to reach the surface of the Earth and also can start the formation of clouds. Recently, it has been shown that organics emitted from biogenic sources react with sulphuric acid of anthropogenic origin and organosulphur compounds are formed. The amount of such compounds has been found to be significant both in the sulphur content and the water-soluble organic fraction.
Systematic investigations will be conducted in the continental and coastal regions of both countries in order to obtain an insight in organic matter atmospheric deposition into natural aquatic systems. The complex methodological approach will be used to investigate the total organic matter, surface active substances, lipids, complexation of metals with organics and sulphur containing species in the aerosol from rural, urban and marine environment.
Sanja Frka Milosavljević, PhD, Division for Marine and Environmental Research, Rudjer Boskovic Institute
Dautović Jelena, B Sc., Division for Marine and Environmental Research, Rudjer Boskovic Institute
Orlović-Leko Palma, PhD, Mining, Geology and Petrology Engineering Department, University of Zagreb
Kiss Gyula, PhD, Air Chemistry Group of the Hungarian Academy of Sciences, University of Pannonia, Hungary
Gelencsér András, DSc, Dept. of Earth and Environmental Sciences, University of Pannonia, Hungary
Hoffer András, PhD, Dept. of Earth and Environmental Sciences, University of Pannonia, Hungary