Short and long term indoor radon concentrations in buildings with different ventilation systems

Long-term exposure to high radon concentration exerts pathological effects and elicits changes in respiratory function, increasing an individual’s risk of developing lung cancer. In health risk assessment of indoor radon, consideration of long-term exposure thereto is necessary to identify a relationship between indoor radon exposure and lung cancer. However, measuring long-term indoor radon concentration can be difficult, and a statistical model for predicting mean annual indoor radon concentrations may be readily applicable. We investigated the predictability of mean annual radon concentrations using national data on indoor radon concentrations throughout the spring, summer, fall, and winter seasons in Korea. Indoor radon concentrations in Korea were highest in the winter and lowest in the summer. We derived seasonal correction and seasonal adjustment factors for each season based on the method proposed by previous study. However, these factors may not be readily applicable unless measured in a specific season. In this paper, we separate seasonal correction factors for each month of the year (new correction factors) based on correlations between indoor radon and meteorological factors according to housing type. To evaluate the correction factors, we assessed differences between estimated and measured mean annual radon concentrations. Roughly 97% of the estimated values were within ±40 Bq/m3 of actual measured values in detached houses, and roughly 85–87% of the estimated values were within ±40 Bq/m3 of the measured values in other residences. In most cases, the seasonal correction factors and the new correction factors had slightly better agreement than the seasonal adjustment factor. For predicting mean annual radon concentrations, the seasonal correction factors or seasonal adjustment factors can be of use when actual measurements of indoor radon concentrations for a specific season are available. Otherwise, the new correction factors may be more readily applicable.

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Comparison of passive and active radon measurement methods for personal occupational dose assessment

Nuclear Technology and Radiation Protection ◽

10.2298/ntrp1601073h ◽

2016 ◽

Vol 31 (1) ◽

pp. 73-78

Author(s):

Elham Hasanzadeh ◽

Fereidoun Mianji ◽

Asghar Sadighzadeh ◽

Farhang Mizani

Keyword(s):

Indoor Radon ◽

Measurement Methods ◽

Dose Assessment ◽

Uranium Mine ◽

Short Term ◽

Radon Measurement ◽

Active Method ◽

Occupational Dose ◽

Radon Concentrations

To compare the performance of the active short-term and passive long-term radon measurement methods, a study was carried out in several closed spaces, including a uranium mine in Iran. For the passive method, solid-state nuclear track detectors based on Lexan polycarbonate were utilized, for the active method, AlphaGUARD. The study focused on the correlation between the results obtained for estimating the average indoor radon concentrations and consequent personal occupational doses in various working places. The repeatability of each method was investigated, too. In addition, it was shown that the radon concentrations in different stations of the continually ventilated uranium mine were comparable to the ground floor laboratories or storage rooms (without continual ventilation) and lower than underground laboratories.

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Effect of Ventilation Type on Radon Concentration at Places of Work

Radiation Protection Dosimetry ◽

10.1093/oxfordjournals.rpd.a082423 ◽

1994 ◽

Vol 56 (1-4) ◽

pp. 61-63 ◽

Cited By ~ 2

Author(s):

E. Oksanen

Keyword(s):

Child Care ◽

Radon Concentration ◽

Natural Ventilation ◽

Indoor Radon ◽

Exhaust System ◽

Air Supply ◽

Care Facilities ◽

Child Care Facilities ◽

Radon Concentrations

Abstract Indoor radon (222Rn) concentrations were measured at 76 child care facilities and 36 schools in southern Finland. The buildings had three different types of ventilation systems: mechanical air supply and exhaust, mechanical exhaust, and natural ventilation, the first being most common. The effect of the ventilation type on the long-term radon concentration was studied in child care facilities. The radon concentrations were highest in the naturally ventilated buildings. The mechanical air supply and exhaust system maintained the lowest values in cold wintertime. In school buildings both the long-term radon concentration and short-term radon and daughter concentrations were measured. The correlation of the ventilation type and the radon concentration was not obvious in this group of measurements. But the radon concentrations and the equilibrium factors were highest in buildings with natural ventilation. Radon concentrations were generally lower during the working hours than during the one-month period, as expected.

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Measurement of radon concentrations for some houses in Al-Najaf city /Iraq

Iraqi Journal of Physics (IJP) ◽

10.30723/ijp.v11i22.352 ◽

2019 ◽

Vol 11 (22) ◽

pp. 51-55 ◽

Cited By ~ 1

Author(s):

Ali A. Al-Hamidawi

Keyword(s):

Solid State ◽

Radon Concentration ◽

Concentration Level ◽

Indoor Radon ◽

Summer Season ◽

Alpha Particles ◽

Indoor Radon Concentration ◽

Long Term Measurement ◽

Radon Concentrations

Measurement of radon concentration level was carried out in 40 houses in Al – Najaf city during summer season of 2012. Long term measurement of indoor of old building radon concentrations have been taken, using a previously calibrated passive diffusion dosimeters containing CR – 39 solid state nuclear track detectors which are very sensitive for alpha particles. The measurement of the indoor radon concentration obtained in summer in these regions ranged from 11.654±4.216 Bq.m-3 to 53.610±8.777 Bq.m-3. The results were within universally permitted levels.

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A Deterministic Model for Estimating Indoor Radon Concentrations in South Korea

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph16183424 ◽

2019 ◽

Vol 16 (18) ◽

pp. 3424

Author(s):

Ji Hyun Park ◽

Cheol Min Lee ◽

Dae Ryong Kang

Keyword(s):

Mass Balance ◽

Building Materials ◽

Deterministic Model ◽

Indoor Radon ◽

Measurement Data ◽

High Concentration ◽

Actual Measurement ◽

Factors Affecting ◽

Radon Concentrations

Estimating long-term exposure to indoor radon is necessary to determine the effects of indoor radon exposure on health. However, measuring long-term exposure to radon is labor intensive and costly. While developing models for estimating indoor radon concentrations are very difficult and unrealistic due to the many factors affecting radon concentrations, several studies have attempted to estimate indoor radon concentrations with mathematical models based on mass balance equations. However, these models are only applicable to specific regions or situations, and some require actual measurement data. This study sought to develop a widely applicable model for estimating mean annual indoor radon concentrations in actual residences considering seasonal variations in indoor radon. The model is based on a mass balance equation using data on geographical factors, building characteristics, meteorological factors, and nationwide radon surveys. The primary factor in our model is the infiltration factor, which can vary according to region, building materials, cracks, floor type, etc. In this study, infiltration factor was calculated according to the type of housing and groundwater usage, and the results thereof were applied to estimate indoor radon concentrations. Overall, measured concentrations and estimates of indoor radon concentrations using the infiltration factor were similar. This model showed better performance than our previous model, except for a few high concentration residences.

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Experience with Short and Long Term Courses of Local Adrenal Steroid Therapy For Ulcerative Colitis

Gastroenterology ◽

10.1016/s0016-5085(62)80117-6 ◽

1962 ◽

Vol 42 (6) ◽

pp. 669-677 ◽

Cited By ~ 18

Author(s):

Jean A. Spencer ◽

Joseph B. Kirsner

Keyword(s):

Ulcerative Colitis ◽

Steroid Therapy ◽

Adrenal Steroid ◽

Short And Long Term

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Short- and Long-Term Results of Total vs Subtotal Thyroid- ectomies in the Surgical Treatment of Graves' Disease

Swiss Surgery ◽

10.1024/1023-9332.7.1.20 ◽

2001 ◽

Vol 7 (1) ◽

pp. 20-24 ◽

Cited By ~ 14

Author(s):

Robert ◽

Mariéthoz ◽

Pache ◽

Bertin ◽

Caulfield ◽

...

Keyword(s):

Recurrent Laryngeal Nerve ◽

Nerve Palsy ◽

Recurrent Laryngeal Nerve Palsy ◽

Laryngeal Nerve ◽

Long Term Results ◽

Graves Disease ◽

Laryngeal Nerve Palsy ◽

Short And Long Term

Objective: Approximately one out of five patients with Graves' disease (GD) undergoes a thyroidectomy after a mean period of 18 months of medical treatment. This retrospective and non-randomized study from a teaching hospital compares short- and long-term results of total (TT) and subtotal thyroidectomies (ST) for this disease. Methods: From 1987 to 1997, 94 patients were operated for GD. Thirty-three patients underwent a TT (mostly since 1993) and 61 a ST (keeping 4 to 8 grams of thyroid tissue - mean 6 g). All patients had received propylthiouracil and/or neo-mercazole and were in a euthyroid state at the time of surgery; they also took potassium iodide (lugol) for ten days before surgery. Results: There were no deaths. Transient hypocalcemia (< 3 months) occurred in 32 patients (15 TT and 17 ST) and persistent hypocalcemia in 8 having had TT. Two patients developed transient recurrent laryngeal nerve palsy after ST (< 3 months). After a median follow-up period of seven years (1-15) with five patients lost to follow-up, 41 patients having had a ST are in a hypothyroid state (73%), thirteen are euthyroid (23%), and two suffered recurrent hyperthyroidism, requiring completion of thyroidectomy. All 33 patients having had TT - with follow-ups averaging two years (0.5-8) - are receiving thyroxin substitution. Conclusions: There were no instances of persistent recurrent laryngeal nerve palsy in either group, but persistent hypoparathyroidism occurred more frequently after TT. Long after ST, hypothyroidism developed in nearly three of four cases, whereas euthyroidy was maintained in only one-fourth; recurrent hyperthyroidy was rare.

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