Abstract. This article presents measurement results of intensity of solar UVA and UVB radiation, as well as UV radiation albedo from various surfaces. The intensity of albedo was measured from natural surfaces, such as: sand, grass, water, and snow. The paper also presents measurements of solar emitted UVA and UVB radiation intensity in the shadow. Ultraviolet radiation intensity and surface albedo was measured using a handy UVA radiation radiometer UVA -365HA, with spectral response of 320-390 nm and a handy UVB radiation radiometer PMA2201, with spectral response of 280-320 nm. The results of measurements show that snow has the maximum albedo -from 50 to 60 per cent, sand -10 per cent, and the minimum albedo is for grass -2 or 3 per cent. The data of experimental measurements of UVA and UVB radiation in the shadow show that maximum reduction of intensity of UVA radiation up to 80%, was at 1 p.m. in comparison with reduction of intensity of UVB radiation to 70% at 2 p.m.
Abstract:Hourly and daily variations of ground-level ozone have been analyzed in relation to meteorological parameters, UVB radiation and radon near the Baltic Sea in Lithuania. An atypical situation with respect to wind domination was observed during the experiment: the wind from the continent was twice as frequent as the wind from the sea. The close correlation between ground-level ozone concentration and UVB radiation intensity was established. The vertical migration directions of ozone and radon were opposite and the negative correlation between these pollutants was observed. The diurnal course of ozone and radon and the influence of meteorological parameters (temperature, relative air humidity, wind speed and direction) on variation of these pollutants have been estimated. It was established that the wind direction domination during the experiment had a significant influence on the variation of ozone and radon concentrations.
Preliminary analysis of the data of ultraviolet (UV) radiation and ground‐level ozone concentration measurements from Rugšteliškes Monitoring Station over the years 2002–2003 is presented. Observations showed that an average UV radiation value in January and July of 2002 differed about 10 times. Maximum intensity of UVA radiation was observed in July (about 2,4 W/m2), and minimal one ‐ in December (0,1 W/m2), the highest UVB radiation intensity was in May (0,09 W/m2), while a minimal UVB radiation value as well as that of UVA was registered in December (0,07 W/m2). Relationship between the highest ozone concentration and UVB radiation values during the summer of the investigation period was found to be linear.
Abstract. The paper presents the assessment of ultraviolet radiation from technical sources. It has been determined that the intensity of UVA radiation is about 10 times higher than the intensity of radiation of UVB. It has been investigated that the intensity of UV radiation during the welding process nonlinearly depends on the strength of the current, namely, if the strength of the current is reduced by 60%, the intensity of UV radiation is reduced by 20%, it also depends on the distance from the source, namely, if the distance is increased 10 times, the intensity of UV radiation is reduced about 25 times. The dose of UVA and UVB radiation from various resources is calculated. Comparison with the minimum erythema dose is submitted. It has been obtained that when the strength of the current is 315 A, the UV radiation dose exceeds 1 MED, namely, UVA ~ 3000, UVB ~300 times. After having carried out the experiment it has been found that the UV radiation emitted from a welder comprises about 80% of UVA, and about 20% of UVB. The results of investigation made in a solarium show that UV radiation from lamps comprises 98% of UVA radiation and 2% -of UVB radiation, while in the Sun rays reaching the Earth UV radiation comprises 96% of UVA and 4% of UVB.
Polychlorinated dibenzodioxins and polychlorinated dibenzofurans (PCDD/F) are highly bioavailable in humans, either through direct inhalation or indirectly by trophic transfer from contaminated food or water. The main sources of pollution with PCDD/F include industrial and non-industrial combustion sources, like domestic contaminated wood burning, house fires, burning of leaves from trees, etc. When looking for alternative energy sources and reduced energy costs, solid waste incineration plants are intended to be built in the vicinity of urbanized areas, and thus, the need emerges for examination and prediction of to what extent the solid waste incineration plants might affect the surrounding ecosystem, air pollution, and human health. Polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) (or simply PCDD/F congeners) belong to the group of semi-volatile organic compounds with environmental stability and long-range transfer in the ambient air. Dioxin isomers are highly toxic and may have carcinogenic and mutagenic effects in humans. PCDD/F is detected in air, water, sediment, plants and animals. PCDD/F is generally distributed in the particulate phase in ambient air. For solid waste incineration plant emissions, the distribution of PCDD/F particles into particles with a diameter of <10 μm is more than 81% of the total particulate matter, and more than 54% of the PCDD/F is distributed into particles with a diameter of <2.5 μm. The aim of this study is to investigate the sources of PCDD/F, emissions and potential hazards, i.e., a toxic equivalent in Lithuania. The measurements were performed in two largest cities of Lithuania Vilnius and Kaunas, where the level of PCDD/F discovered was from 0.015 to 0.52 pg/m3 and from 0.02 to 0.05 pg/m3, respectively. The sites for the monitoring were selected based on their proximity to the locations of the planned cogeneration power plants in these cities.
In this article the erythemally weighted UV radiation intensity variations during 2002-2011 were analysed. Also UV radiation intensity and total ozone data in this paper were analysed, because the UV index is directly dependent on the intensity of UV radiation, and most of the UV radiation is absorbed by stratospheric ozone. During 2002-2011 in the course of UV index - the upward trend was observed, and in the total ozone values - the downward trend was observed. During the investigated period in Lithuania the maximum UV index values (very high) on clear sky summer days were determined.
The ultraviolet radiation intensity, the total ozone amount, and the ground-level ozone concentration are the three essential factors having impact on the vegetation, materials, the human health, and the atmospheric chemistry. The analysis of the relationship among these parameters was made for the obtained data under Lithuanian rural conditions. UVB radiation intensity and ground-level ozone concentration were measured at the Rūgšteliškės monitoring station and total ozone data were obtained from the Kaunas meteorological station during [2002][2003]. Cloudless or slightly cloudy days of the period were chosen for the analysis. The results showed a strong dependence (R = 0.73 for 2002 and R = 0.75 for 2003) between the UVB radiation intensity and the ground-level ozone concentration. The photochemical ozone generation at the Rūgšteliškės station, located in the unpolluted forest area, is related to the reaction between natural volatile organic compounds emitted from the vegetation at low nitrogen oxide level. A more pronounced relationship between the UVB radiation intensity and the ground-level ozone concentration was found in 2003 and it could be related to specific meteorological conditions of the summer of 2003. A negative correlation (R > −0.86) was determined during cloudless days between the UVB radiation and the total ozone.
Polichlorinti dibenzo-p-dioksinai ir polichlorinti dibenzofuranai (PCDD/F) toksiniai organiniai junginiai atsiranda medžiagų degimo metu išsiskiriančiuose dūmuose, o patekę į organizmą – kaupiasi poodiniame riebaliniame sluoksnyje. Junginiai pasižymi santykinai ilga pusėjimo trukme, tad kartu su dūmais atsiradę atmosferoje oro srovių gali būti nunešti didelius atstumus nuo juos emitavusių šaltinių. Nerimą keliantis junginių kiekio ore didėjimas šiandien jau nustatomas specialiais tyrimų metodais bei jautriais prietaisais, tačiau mažas jų dozes užterštoje aplinkoje, maiste ar žmogaus organizme vis dar labai sunku aptikti. 2017 m. gegužės ir rugpjūčio mėn. PCDD/F koncentracija Vilniaus mieste atitinkamai siekė 0,03 pg/m3 ir 0,016 pg/m3, 2018 m. vasario mėn. padidėjo iki 0,52 pg/m3, o 2018 m. spalio mėn. vėl sumažėjo iki 0,015 pg/ m3. Išmatuotos vertės Vilniaus mieste koreliuoja su koncentracijomis, nustatytomis Vakarų Europos šalyse. Pagal Europos Sąjungos ir Lietuvos Respublikos galiojančius teisės aktus PCDD/F metinė ribinė vertė turėtų neviršyti 100 pg/m3, tačiau vis dar nėra nei nacionalinėse, nei ES direktyvose nustatyta šių toksiškų junginių paros ribinė vertė. Pasaulio sveikatos organizacija (PSO) rekomenduoja – 3·106 pg/m3. Mūsų atlikti eksperimentiniai ir teorinio modeliavimo tyrimai leidžia įvertinti dabartinę PCDD/F junginių koncentraciją ore ir prognozuoti jų kaitą, įvertinant naujų taršos šaltinių atsiradimą.
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