IMPACT OF SULPHUR DIOXIDE ON THE RESPIRATORY SYSTEM OF TBILISI POPULATION.

The possible relationship between levels of sulphur dioxide (SO2) in the air and the rate of respiratory diseases has been studied. Results of monitoring of main contaminants of outdoor air were analyzed and they are reflected in Environmental Report 2015. Information on morbidity by respiratory system diseases of Tbilisi population is has been taken from 2011-2015 reports of the National Center of Disease Control. Identified that there is no consistent correlation between sulphur dioxide concentration in the air and respiratory system disease rates in the population, including children. Obtained data demonstrated that during the study period maximum SO2 concentration was registered in 2015 - 0,14 mg/m3 (exceeding almost 3 times maximum permissible concentration - 0,5 mg/m3) and in the same year high morbidity rates are registered (incidence -18106,08), though the lowest rates are registered in 2011 (0,09 mg/m3), when incidence of respiratory system diseases in this period (13103.2) exceeds the rates registered in 2012, 2013 and 2014 (12736.4, 11336.3, 13009.0 accordingly). There is no direct correlation between the morbidity rates of 0-15 year old children and SO2 concentration. Maximum incidence rate is registered in 2015 (48487.0) and in the same year is also registered maximum concentration of SO2 (0,14 mg/m3), whereas the lowest rate is registered in 2013 (35538,70), when SO2 concentration in 2013 is lower only by 0.02 mg/m3 compared to the concentration in 2015. Direct correlation between morbidity with asthma in children and concentration of SO2 was not identified. Prevalence of asthma is minimal in 2014 (65,4), maximal in 2012 (207,1), whereas SO2 concentration in 2014 (0,13 mg/m3) exceeds the concentration in 2012 (0,12 mg/m3). It has to be considered, that besides SO2 there are many small intensity adverse factors, which are also risk factors for development of respiratory diseases. Isolated action of these factors with certain concentrations may not demonstrate any adverse effects on human health, but the combined effect of their action is stronger and obviously will affect general health and specifically - respiratory system. Implementation of urgent measures for further improvement of their ambient air quality has been recommended, which will be the basis for minimizing of many chronic diseases.

[Irradiation doses of population in mountainous Adjara region of Georgia].

Radionuclide content of food and water in high mountainous regions of Georgia - Adjara (Keda, Shuakhevi, Khulo) has been studied, internal and total irradiation doses for the population have been defined and preventive measures for its reduction have been proposed. Internal irradiation dose for the population caused by K-40 was identified as 0,63 mSv/y, total irradiation dose - 1,73 mSv/y, that slightly exceeds acceptable levels, due to this it seems desirable to provide some measures with aim to reduce the radiation dose of the population and conduct further observation of the radiation situation. Measures intended to reduce irradiation doses includes: provision of population with less radioactive water sources, the regulation of medical radiation procedures (mostly - X-ray diagnostic procedures), the rational use of fertilizers with 40K content, construction of buildings on the territories with the lowest values of gamma radiation and radon release from soil, use of materials with low content of natural radionuclides for building construction, provision of premises with effective ventilation and radiation monitoring of buildings at any stages of construction, reconstruction or repair.

[Radioecological situation of Racha-Lechkhumi region of Georgia and hygienic assessment of external irradiation doses of population].

Radioecological situation in Racha-Lechkhumi region of Georgia (Ambrolauri, Oni, Lentekhi, Tsageri districts) and annual effective doses of external irradiation of population have been studied. It was found that outdoor radiation background in Racha-Lechkhumi region is 58.0-169.0 nGy/h; average index is 108.9 nGy/h. Indoor radiation background is 68.0-192.0 nGy/h; average index is 137.4 nGy/h. The average annual effective dose of external irradiation of population in Racha-Lechkhumi region is 0.81 mSv/y, which exceeds the dose of similar type registered in most of countries. The implementation of adequate preventive measures for its reduction is required.

[The radiation background and hygienic assessment of external irradiation doses of population in some mountainous regions of Georgia].

The radioecological situation of Mtskheta-Mtianeti region of Georgia has been studied. Doses from external irradiation were determined and estimated. The average value of radiation background (RB) of open areas in Mtskheta-Mtianeti region accounts 84.6 nGy/h, which is nearly equal to the average values in the countries of western Europe. This shows that investigated territories have high natural radiation background, which considering the geographical position and geophysical situation of Georgia is normal. The average value of radiation background of buildings in investigated territories accounts 120.4 nGy/h, which is little more than worldwide average value. The average annual dose from external irradiation (without radon component) for population of Mtskheta-Mtianeti region accounts 0.99 mZv/y, which is slightly more than worldwide average value. Since approximately 2/3 of effective equivalent dose comes from internal radiation and 1/3--from external radiation, it's reasonable to suppose that the radiation load of population of Mtskheta-Mtianeti region is significant and requires implementation of radiation dose reduction measures.

[Hygienic assessment of irradiation doses of Mtskheta-Mtianeti region' population].

Radionuclide content in the food and water in Mtskheta-Mtianeti region of Georgia has been studied, internal and total irradiation doses for the population have been defined and preventive measures for its reduction were detected. Internal irradiation dose for the population due to (40)K was identified as 1,58 mSv/y, total irradiation dose (external and internal irradiation) - 2,57 mSv/y, that is to some extent high than acceptable levels. To reduce the total irradiation dose of a population it is necessary to prohibit the use of high activity water for drinking; provision of the population with new sources of low activity water; minimize and control of irradiation doses from artificial sources including means of regulation of medical radiological procedures and rational use of fertilizers with (40)K content.