ИСТИНА

Mercury is one of the priority pollutants been selected for monitoring in environmental media by international organizations and research programs. The lifetime of mercury in its elemental form is estimated to be from days to months which is longer than for many other pollutants. Being emitted into the atmosphere mercury could be transported for long distance and are detected far from sources, including remote areas and background territories such as biosphere reserves. The program of integrated background monitoring network (IBMoN) in the Russia incudes the measurements of Hg in atmosphere and other environmental media. However, there is only one IBMoN station, in Prioksko-Terrasny biosphere reserve, provided long term data on concentrations of mercury both in air and precipitation for the period since 1980s. The sampling area is located in remote area of Central European Russia to the south from Moscow at the boundary of forest zone. The samples are collected in glass tube absorber by low-volume force pumping of air through the silver amalgam sorbent. In laboratory a mercury concentration is determined by means of atomic absorption spectrometry. In this research on trend estimation we paid more attention to the period since 1990s by using two approaches. The first way is the application of well-known linear trend analysis with the Mann-Kendall test and Sens slope approach to the averages. It was realized into MAKESENS package within Excel software. The results were prepared for both whole time series and their sub-periods of different tendencies. The second approach is the approximation of trend by bi-exponential curve with filtering periodic (seasonal) fluctuations. The monthly average values were tested and evaluated with the use of ad hoc MSC-East data tool (special FORTRAN program prepared by Modeling Center of EMEP, Moscow). Presented results of estimation are ambiguous for interpretation and demonstrate various tendencies for different time periods.