Tveganje za izpostavljenost radonu v domovih starejših občanov

magistrsko delo

Nina Vadnjal (Author), Borut Poljšak (Reviewer), Mateja Dovjak (Mentor), Janja Vaupotič (Co-mentor)

Abstract

Uvod: Radon (Rn) je naravni radioaktivni plin, ki je v zemlji zelo razširjen. Proti površju potuje s talnim zrakom in se v primeru netesnega stavbnega ovoja v stiku z zemljino kopiči v kletnih in pritličnih prostorih stavb. Ogljikov dioksid (CO2) je prisoten v atmosferi, kjer deluje kot toplogredni plin. Nastaja tudi pri celičnem dihanju in se zato kopiči v zaprtih prostorih. Rn in CO2 imata v povišanih koncentracijah negativne učinke na zdravje, po drugi strani pa sta zanesljiva indikatorja prezračevanja prostorov. V raziskavi smo izvedli meritve koncentracij Rn in CO2 v zraku treh domov starejših občanov (DSO), ki se na zemljevidu tveganja za prisotnost Rn v stavbah nahajajo na treh različnih območjih tveganja, in sicer z nizkim (DSO-N), zmernim (DSO-Z) in visokim (DSO-V) tveganjem. Namen: V izbranih prostorih DSO smo preučili dinamiko Rn in CO2 v zraku kot dejavnikih tveganja za zdravje, predvsem z vidika lokacije stavbe, njenih gradbenotehničnih karakteristik in sistemov prezračevanja ter specifik uporabnikov. Z izračunom efektivnih doz smo ocenili vpliv na zdravje zaposlenih in varovancev domov, glede na prisotnost Rn (in njegovih razpadnih produktov, RnP) v zraku. Metode dela: Meritve koncentracij Rn in CO2 smo izvedli v hladni in topli polovici leta, v obdobju 2021?2022. Najprej smo izmerili trenutne koncentracije Rn zjutraj v neprezračenih prostorih, ko so vrednosti slednjega praviloma najvišje. Na osnovi teh pridobljenih podatkov o trenutni koncentraciji Rn smo izbrali prostore za nadaljnje večtedenske kontinuirne meritve koncentracij Rn in CO2. Pri ogledu stavb smo popisali njihove gradbenotehnične karakteristike v ocenjevalni list, v prostorih pa smo posebno pozornost namenili iskanju potencialnih vstopnih točk za Rn. Tesnost stavbnega ovoja smo preverili z izračunom stopnje infiltracije zraka skozi stavbni ovoj v stavbo na osnovi kontinuirnega poteka koncentracije CO2. Iz povprečnih koncentracij Rn smo izračunali celoletne efektivne doze, ki jih prejmejo zaposleni in varovanci DSO. Rezultati: Povprečne koncentracije Rn (Bq m–3) v topli/hladni polovici leta so bile naslednje: 54/185 v DSO-N, 91/60 v DSO-Z in 176/160 v DSO-V. Skupno število preseganj mejne koncentracije Rn 300 Bq m–3 je bilo v topli/hladni polovici leta naslednje: 5/17 v DSO-N, 1/4 v DSO-Z in 19/39 v DSO-V. Vsak DSO ima drugačno shemo prezračevanja, in sicer najmanj pogosto zračijo v DSO-N, bolj pogosto v DSO-Z in najbolj pogosto v DSO-V. Povprečne koncentracije CO2 (ppm) so odraz zasedenosti prostorov in so bile v hladni polovici leta naslednje: 543 v DSO-N, 619 v DSO-Z in 458 v DSO-V. Število preseganj mejne koncentracije CO2 1000 ppm pa je bilo v hladni polovici leta naslednje: 7 v DSO-N, 21 v DSO-Z in 0 v DSO-V. Povprečne celoletne efektivne doze (mSv) za zaposlene/oskrbovance so naslednje: 0,54/0,02 v DSO-N, 0,45/0,29 v DSO-Z in 1,15/0,21 v DSO-V. Razprava in zaključek: Koncentracije Rn so bolj odraz prezračevanja prostorov kot območja tveganja na radonskem zemljevidu ali gradbenotehničnih karakteristik stavb. Koncentracije CO2 dodatno potrjujejo različne sheme zračenja prostorov, ki je v DSO-V zadostno, v DSO-N in DSO-Z pa bi ga bilo treba povečati. Zadovoljivo nizka koncentracija CO2 in povišana koncentracija Rn v zraku enega od prostorov DSO-V kaže na močan vir Rn, ki vstopa v prostor iz revizijskega jaška za kanalizacijo. V tem prostoru koncentracija Rn v jutranjih urah največkrat preseže mejno vrednost, zato priporočamo sanacijo. Efektivne doze so višje v hladni kot v topli polovici leta, vendar niso skrb vzbujajoče. Z bolj pogostim zračenjem prostorov v DSO-N in DSO-Z se bodo efektivne doze znižale. Če bodo v prostoru v DSO-V, kjer prejme zaposlena oseba celoletno efektivno dozo 2,19 mSv z ustreznimi sanacijskimi ukrepi znižali koncentracijo Rn, se bo znižala tudi efektivna doza.

Keywords

magistrska dela;sanitarno inženirstvo;radon;CO2;meritve;tesnost stavbnega ovoja;efektivna doza;tveganje;domovi starejših občanov;

Data

Language:	Slovenian
Year of publishing:	2022
Typology:	2.09 - Master's Thesis
Organization:	UL ZF - University College of Health Studies
Publisher:	[N. Vadnjal]
UDC:	614
COBISS:	124211971
Views:	15
Downloads:	12
Average score:	0 (0 votes)
Metadata:

Other data

Secondary language:	English
Secondary title:	Risk of radon exposure in elderly care homes
Secondary abstract:	Introduction: Radon (Rn) is a radioactive natural gas widespread in the earth's crust. It travels towards the surface with the soil air and, if the building envelope in contact with the ground is not tight, accumulates in the basement and ground floor. Carbon dioxide (CO2) is present in the atmosphere and acts as a greenhouse gas. It is also produced during cellular respiration and therefore accumulates in closed spaces. Rn and CO2 in elevated concentrations have adverse effects on health, but on the other hand are reliable indicators of room ventilation. In this research, we measured Rn and CO2 concentrations in the air of three elderly care homes (DSO), located in three different areas, concerning the radon risk map for the presence of Rn in buildings: on low (DSO-N), moderate (DSO- Z) and high (DSO-V) risk area. Purpose: In the selected premises of the DSO, we studied the dynamics of Rn and CO2 in the air as risk factors for health; especially from the point of view of the location of the building, its construction-technical characteristics and ventilation systems, as well as the specifics of the users. By calculating the effective doses received by exposure to Rn (and its progeny, RnP) in the air, we assessed the impact on the health of employees and residents. Experimental: Rn and CO2 concentrations were measured in the cold and warm half of the year, from 2021 – 2022. First, we measured the instantaneous Rn concentrations in unventilated rooms in the morning, when the values are generally the highest. Based on the instantaneous Rn concentrations, we selected the premises for further continuous measurements of Rn and CO2 concentrations over several weeks. When visiting the buildings, we recorded their construction and technical characteristics in the evaluation sheet. We paid particular attention to the search for potential entry points of Rn to the rooms. The tightness of the building envelope was checked by calculating the rate of air infiltration through the building envelope into the building, based on the continuous measurements of CO2 concentration. From the average Rn concentrations, we calculated the annual effective doses received by employees and residents in each DSO. Results: The average Rn concentrations (Bq m–3) in the warm/cold half of the year were as follows: 54/185 in DSO-N, 91/60 in DSO-Z and 176/160 in DSO-V. The total exceedings of the Rn limit concentration of 300 Bq m–3 in the warm/cold half of the year were as follows: 5/17 in DSO-N, 1/4 in DSO-Z and 19/39 in DSO-V. Each DSO has a different ventilation scheme; they ventilate least often in DSO-N, more often in DSO-Z and most often in DSO-V. The average CO2 concentrations (ppm) reflect the occupancy of the premises and were the following in the cold half of the year: 543 in DSO-N, 619 in DSO-Z and 458 in DSO-V. The total exceedings of the CO2 limit concentration of 1000 ppm were in the cold half of the year as follows: 7 in DSO-N, 21 in DSO-Z and 0 in DSO-V. The average yearly effective doses (mSv) of employees/residents are as follows: 0.54/0.02 in DSO-N, 0.45/0.29 in DSO-Z and 1.15/0.21 in DSO-V. Discussion and conclusion: Rn concentrations reflect more room ventilation than risk areas on the radon map or building construction-technical characteristics. The CO2 concentrations further confirm the different room ventilation schemes, which is sufficient in DSO-V, but it would be necessary to increase it in DSO-N and DSO-Z. Satisfactorily low CO2 concentration and elevated Rn concentration in the air of one of the DSO-V rooms indicate a strong source of Rn entering the room from the sewage audit shaft. In this room, the concentration of Rn in the morning most often exceeds the limit value; therefore, we recommend remediation. The effective doses are higher in the cold than in the warm half of the year, but they are not worrying. The effective doses will decrease with more frequent ventilation of the premises in DSO-N and DSO-Z. If the Rn concentration in the room of the DSO-V, where the employee receives a yearly effective dose of 2.19 mSv, were reduced with appropriate remedial measures, the effective dose would decrease too.
Secondary keywords:	master's theses;sanitary engineering;radon;CO2;measurements;building envelope tightness;effective dose;risk;elderly care homes;
Type (COBISS):	Master's thesis/paper
Study programme:	0
Embargo end date (OpenAIRE):	1970-01-01
Thesis comment:	Univ. v Ljubljani, Zdravstvena fak., Oddelek za sanitarno inženirstvo
Pages:	89 str., [5] str. pril.
ID:	16626745