Indoor radon levels in urban Hyderabad area, Andhra Pradesh, India

Our plain-English summary of Indoor radon levels in urban Hyderabad area, Andhra Pradesh, India, by M. Sreenath Reddy, P. Yadagiri Reddy, K. Rama Reddy, et al (Radiation Protection Dosimetry, 2008).

The study

• Authors: M. Sreenath Reddy, P. Yadagiri Reddy, K. Rama Reddy, K.P. Eappen, T.V. Ramachandran, Y.S. Mayya
• Journal: Radiation Protection Dosimetry
• Published: 2008;132(4):403-8
• Cited by: 3 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Indoor radon levels in urban areas of Hyderabad, Andhra Pradesh, India were measured by a time integrated method using solid state nuclear track detector-based dosemeters. Results show that the radon levels varied widely in the area ranging from 17 to 311 Bq m(-3) with a geometric mean value of 52.8 Bq m(-3) (GSD=1.7). Cumulative frequency distribution of radon levels gave a best fit on a log-normal scale. Measurements were carried out for 1 y, segregating the measurement periods in accordance with seasonal changes. Soil samples from the region were also analysed for natural radionuclides to study its effect, if any, on indoor radon levels. Dwellings categorised based on construction types showed that the average radon levels in the order tiles (TLE)>asbestos (ASB)>concrete (RCC) for the roof structures. The estimated radon levels in the study area are relatively higher than the country's average value of 23 Bq m(-3) and global average value of 30 Bq m(-3).

In plain English

This study measured radon, a natural radioactive gas, inside homes in urban Hyderabad, India. It did not measure asbestos fibers or study any disease. Asbestos appears only as one of the roof types whose homes' radon levels were compared. As part of a nationwide Indian radon survey, the researchers hung passive radon detectors in the living rooms of 100 randomly selected dwellings for one year, changing them with the seasons. Indoor radon ranged from 17 to 311 becquerels per cubic metre (Bq/m3), with a geometric mean of 52.8. About 35% of houses were below 40 and about 10% were above 100. Winter levels were slightly higher than summer (ratio 1.17). Average radon was highest in mud-floored homes (148, in 10 homes). It was higher in bare-brick homes (110, in 9 homes) than in plastered and painted ones (58, in 45 homes). Among stone-floored homes, average levels ranked tiled roofs above asbestos roofs above concrete roofs. The authors suggested ventilation as the explanation but said more statistically significant data were needed to conclude. The authors concluded that Hyderabad's radon levels were relatively high compared with India's average of 23 Bq/m3 and the global average of 30 Bq/m3.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Cross-sectional measurement survey of indoor radon in homes using passive (time-integrated) track-detector dosemeters over one year, part of a nationwide survey coordinated by the Bhabha Atomic Research Centre
• Who was studied: 100 dwellings in urban Hyderabad, Andhra Pradesh, India; most had reinforced concrete roofs and brick walls, the rest mostly asbestos roofs and a few tiled roofs and mud walls
• Exposure: Indoor radon gas (radon-222), compared across floor, wall and roof types. Asbestos was examined only as a roofing material (asbestos roofs), not as a fiber exposure.
• Main results:
  • Across all dwellings, radon ranged from 17 to 311 Bq/m3, with a geometric mean of 52.8 Bq/m3 (GSD 1.7)
  • About 35% of houses had radon below 40 Bq/m3, and about 10% had radon above 100 Bq/m3
  • Seasonal variation was almost insignificant; the ratio of winter to summer radon levels was 1.17
  • Mud-floored homes (10 dwellings) had the highest average radon, 148 Bq/m3 (range 29 to 311). Stone-floored homes (65) averaged 61, concrete-floored homes (12) averaged 54, and mosaic-floored homes (8) averaged 48
  • Homes with bare brick walls (9 dwellings) averaged 110 Bq/m3, compared with 58 Bq/m3 in homes with plastered and painted brick walls (45 dwellings)
  • Among stone-floored homes, average radon was highest under tiled roofs, then asbestos roofs, then concrete (RCC) roofs. The authors suggested that tile and asbestos roofs give more ventilation. The text gives no numbers for roof types; these appear only in a figure.
  • One closed room with Proterozoic Bhimas limestone (Thandoor stone) flooring reached a radon peak close to 1.5 kBq/m3. The limestone's uranium content was estimated at around 500 ppm
• The authors' conclusion: The authors concluded that radon levels in urban Hyderabad are relatively high compared with many other parts of India, the national average of 23 Bq/m3 and the global average of 30 Bq/m3. They related this to local rock hills containing comparatively higher uranium-238 and thorium-232.
• Limitations the authors state:
  • Too few homes in each construction category to draw a statistical conclusion about floor, wall or roof type
  • Statistically significant data and study of other factors (building-material radioactivity, ventilation) are needed before the roof-type finding can be explained

Related studies

• Case-control study on lung cancer and residential radon in western Germany — L. Kreienbrock, M. Kreuzer, et al. (2001)
• Indoor air quality differences between urban and rural preschools in Korea — C. Yoon, K. Lee, et al. (2011)
• Increased lung cancer risk due to residential radon in a pooled and extended analysis of studies in Germany — H.E. Wichmann, A.S. Rosario, et al. (2005)
• Indoor air pollutants. A literature review — T.F. Cooke (1991)
• A pilot study of indoor air quality in screen golf courses — S.J. Goung, J. Yang, et al. (2015)
• Emerging indoor pollutants — T. Salthammer (2020)

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