Acta Facultatis Ecologiae - TechnickÃ¡ univerzita vo Zvolene

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61ACTA FACULTATIS ECOLOGIAE, 16: Suppl. 1, 61– 66 Zvolen (Slovakia), 2007OUTDOOR RADON AS AN INDICATOR OF ATMOSPHERICSTABILITYMartin Bulko – Karol Holý – Anna Polášková – Ján Hrvoľ – Ján ŠimonFaculty of Mathematics, Physics and Informatics, Comenius University, Mlynská dolina, 841 04 Bratislava, Slovakia,e-mail: bulko@fmph.uniba.skABSTRACTBulko M., Holý K., Polášková A., Hrvoľ J. & Šimon J. Outdoor Radon as an Indicator of AtmosphericStabilityThis work deals with the potential use of radon as an indicator of atmospheric stability. Stability of theatmosphere is a parameter that can be used e.g. for quantitative assessment of pollutant dispersion in theground layer of the atmosphere. A rather good agreement was found between the courses of radon activityconcentration and stability indexes determined by modified Turner classification of atmospheric stability.The courses of radon concentration tend to lag behind the courses of stability indexes; this lag is of theorder of hours. It can be caused by the fact that unlike radon activity concentration in the ground layer ofthe atmosphere, the reaction of stability indexes to the change of meteorological parameters is immediate,because they are defined by table values. Several analyses presented in this paper also showed that there isa close connection between the time change of radon activity concentration and the time change of stabilityindexes. Then radon seems to be a good indicator of vertical mixing processes in the atmosphere, butfurther research on this issue is needed to confirm these results.Key words: outdoor radon, atmospheric stability, stability indexINTRODUCTIONDevelopment of industry and engineering hashad many adverse effects on the environment.A need for controlling the environment pollutionand its impact on the earth‘s biosphere is thereforestill topical. It is known that the aggregation ofpollutants in the lowest layers of the atmosphereoccurs under especially stable atmospheric conditions.Hence the degree of atmospheric stability isone of the most important parameters for evaluationof air pollution [1].Atmospheric stability can be determined on thebasis of meteorological parameters like the intensityof solar radiation, cloudiness, cloud height, visibility,period of day (daytime or night-time), windspeed and possibly temperature gradients. Numerousstudies [2, 3, 4] have shown that concentrationof gas (e.g. radon gas) in the atmosphere dependsmainly on vertical atmospheric stability. For thisreason, monitoring of 222 Rn activity concentrationcan bring information about stability of the atmospherein polluted area. 222 Rn is especially suitablefor this purposes since the radon exhalation ratefrom soil is approximately even, half-life of radonis long enough so that radon is able to escape bymeans of molecular diffusion from soil air into theatmosphere and because radon activity concentrationcan be measured with sufficient accuracy.The aim of this study was to examine closelythe relation between 222 Rn activity concentrationand indexes of stability determined by modifiedTurner method of atmospheric stability classification.At least certain agreement between the quantitiescan be expected because some studies indicatethat the variations of radon activity concentrations
62and the variations of quantities used for determiningthe stability indexes are also in good mutualagreement [1].METHODS222Rn activity concentrations were measuredat the Faculty of Mathematics, Physics and Informatics,Comenius University (FMPI CU) campus,Bratislava. The sampling air was collected at theheight of 1.5 m above the earth’s level and suckedthrough a large volume (4.5 l) scintillation chamberwith a flow rate of 0.5l/min [5]. Subsequently, radonactivity concentrations belonging to two-hourintervals were determined from the recorded countrates using the Ward method [6].Meteorological parameters required for determiningthe stability indexes were acquired at theDivision of Meteorology and Climatology, FMPICU. The stability indexes were determined by Turner’smethod of atmospheric stability classificationmodified by Nester and Reuter [7]. This classificationcomprises 7 degrees of atmospheric stability:1 – extremely unstable, 2 – unstable, 3 – slightlyunstable, 4 – neutral conditions, 5 – slightly stable,6 – stable, 7 – extremely stable. Due to strongvertical mixing caused by global solar radiation,unstable conditions are likely to occur during theday, while stable ones during the night when temperatureinversions are in effect.RESULTS AND DISCUSSIONFor the purposes of evaluation of the relationshipbetween radon activity concentration and stability indexesthere were carried out thorough analysis of 6months (August, September and October of the years1994 and 1998). Due to limited space available weprovide in this paper only the analysis of a single representativemonth – August 1998.In the picture below (Fig. 1) there are depictedsmoothed courses of radon activity concentrationand calculated stability indexes.The correlation between these time courses israther weak (R = 0,38). However, after a closerlook one can see that the variations are mutuallyshifted. We therefore decided to shift the stabilityindexes 2, 4 and 6 hours forward in time, respectively.The highest degree of correlation was achievedby a 4-hour shift of stability indexes againstradon activity concentration (Fig. 2). The correlationcoefficient improved from 0.38 to 0.64, whichattests that there is a good agreement between thecourses. This approximately 4-hour shift was alsoconfirmed for the rest of the analysed months.Fig. 3 clearly shows the main difference betweenvariations of radon activity concentration andstability indexes. While the mean daily values ofstability indexes remain virtually constant duringthe month, the mean values of radon activity concentrationshow a significant degree of variability.A( 222 Rn) [Bq.m -3 ]201510501 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31Day1086420Stability indexFig. 1 Variations of smoothed courses of radon activity concentration and stability indexes in August 1994A( 222 Rn) [Bq.m -3 ]201510501 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31Day1086420Stability indexFig. 2 Variations of smoothed courses of radon activity concentration and stability indexes in August 1994.Time-courses of stability indexes are shifted 4 hours forward in time
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Acta FacultatisEcologiaeJournal of
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OBSAH / CONTENTSISOL M., MICHALÍKO
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5ACTA FACULTATIS ECOLOGIAE, 16: Sup
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Page 20 and 21: 19are lower in ill patients compare
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Page 25 and 26: 24- multimode cavities are usually
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Page 29 and 30: 28Tradescantia paludosa 02 test and
Page 31 and 32: 30Tab. 5: Results of positive contr
Page 36 and 37: 35DISCUSSIONThe ionising radiation
Page 40 and 41: 39222Rn is produced by radioactive
Page 42 and 43: 41180160140this reason we also pick
Page 44: 435001450400350hKz0,8h [m]300250200
Page 47 and 48: 46deposit is that stripped in off-l
Page 49 and 50: 48TruenessTrueness was determined i
Page 51 and 52: 50MATERIAL AND METHODSChloroform (p
Page 53 and 54: 52absorbance [a.u.]1,000,750,500,25
Page 55 and 56: 54Tab. 1: Rrequirements determinati
Page 57 and 58: 56Methods of VOC testing were set a
Page 60 and 61: 59Tab. 6: ContinuedSamples withsurf
Page 64 and 65: 63One of the possible explanations
Page 66 and 67: 65Ai - Ai-1 [Bq.m -3 ]86420-2-4-6-8
Page 70 and 71: 69BiodegradabilityThe great variety
Page 72 and 73: 71degradation starts of late days,
Page 74 and 75: 73Fig. 4 Treated (after 28 days of
Page 76: 75parameters of the cutting process
Page 80 and 81: 79Fraction: D (residual rest) prese
Page 82: 81was not confirmed. Maximum of mer
Page 85 and 86: 84Fig. 1 Schematic diagram of atomi
Page 87 and 88: 86Alpha spectrometryAlpha spectrome
Page 89 and 90: 8880007000y = 6622xR 2 = 0.939SIMS
Page 94 and 95: 93Gemer according to the German mod
Page 96 and 97: 95Tab. 1 Results of the chemical an
Page 98 and 99: 97Continuation of Tab. 2 Results of
Page 100 and 101: 99Vlčia Dolina and from the reserv
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Page 104 and 105: 103mg.dm -3mg.dm -35,004,003,002,00
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Page 110 and 111: 109Sample site 1 Sample site 2 Samp
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111As for the sampling time (Fig. 5
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113ACTA FACULTATIS ECOLOGIAE, 16: S
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115Typha latifolia, Carex sp., Scir
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117conditions for decomposition of
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121from the background (derived fro
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12311. PETROVSKÝ, E., ELWOOD, B.:
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1272.52.0Correlation coefficient 0,
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131RESULTS AND DISCUSSIONTable 2 gi
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135V-1 BOREHOLEThe courses of 222 R
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137AV-2 (40m) 2006A ( 222 Rn) [kBq/
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139soaks into the soil, another par
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143Fig. 2 The continuous monitoring
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145Indoor radon activity concentrat
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149Fig. 1 Podlipa dump-fieldCanada)
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151concentrations of Fe. Cu. Cd. Ni
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153DUMP-FIELDREFERENCE SITEppm15001
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155Fig. 5 Compression of wood forma
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157decrease in the following order:
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161SPECIFIC EXAMPLES OFFACTORS THAT
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165The methods developed to incorpo
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167The effects of wind on ozone con
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169Fig. 6 Mean total and stomatal f
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171transport modelling in North Ame
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Acta Facultatis Ecologiae, Volume 1
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