Estimation of the residential radon levels and the annual effective dose in dwellings of Shiraz, Iran, in 2015

Abstract

IntroductionRadon is the second most important cause of lung cancer after smoking. Thus, the determination of indoor radon concentrations in dwellings and workplaces is an important public health concern. The purpose of this research was to measure the concentration of radon gas in residential homes and public places in the city of Shiraz and its relationship with the type and age of the buildings as well as the type of materials used to construct the building (brick, block). We also determined the radon dosages that occupants of the building would receive.MethodsThe present study is a descriptive-analytical and cross-sectional research that was conducted on the building’s indoor air in the city of Shiraz in 2015. Using geographic information system (GIS) software and a spatial sampling cell with an area of 25 square kilometers, 200 points were selected. In this study, we used passive diffusive samplers as Solid State Nuclear Track Detector (SSNTD) CR-39 polycarbonate films for three months in the winter. Sampling was conducted in accordance with the U.S. Environmental Protection Agency’s protocol. We determined the concentrations of radon gas at the time of sampling, and calibration factors were determined. The data were analyzed by IBM-SPSS, version 20, descriptive statistics, Kruskal-Wallis, and Mann–Whitney tests.ResultsThis study showed that the average radon concentration was 57.6 ± 33.06 Bq/m3 in residential dwellings. The average effective dose was 1.45 mSv/y. The concentration of radon in 5.4% of the houses was found to be greater than 100 Bq/m3, which is above the level allowed by the World Health Organization (WHO).ConclusionSince radon is the second leading cause of lung cancer, it seems necessary to increase the public’s awareness of this issue and to take action to reduce radon in homes when the concentrations are above the WHO’s guideline.

First indoor radon mapping and assessment excess lifetime cancer risk in Iran

“…Subsequently, in different provinces and cities of Iran, the program has been implemented sporadically and the results of these monitoring are published in the form of scientific papers. For example, the most recent researches carried out in Northern Iran [4], Central Iran [5], Tehran [6], Tabriz [7], Isfahan [8], Shiraz [9], Mashhad [10], Hamedan [11], Ramsar [12], Yazd [13], Qom [14], Kermanshah [15], Khoram Abad [16], and Minab [17] can be mentioned. Despite some scattered regional indoor radon surveys in Iran, radon mapping has not been carried out yet to increase awareness of the hazards of exposure to radon and to target future radon surveys.…”

“…The annual effective dose by the indoor air radon was estimated by the following equation:Annual effective dose (DT) = CR × D ×H × F × T (mSv/yr) [9,18,19]. Where: CR = Radon concentration (Bq/m 3 ); D = Dose conversion factor (9 × 10 −6 mSv/hr per Bq/m 3 ); H = Indoor occupancy factor (0.8); F = Indoor radon equilibrium factor (0.4); and T = Number of hours in a year (24 h × 365 days =8760 h/yr).…”

Radiological Assessment of Indoor Radon and Thoron Concentrations and Indoor Radon Map of Dwellings in Mashhad, Iran

“…Measuring indoor radon and thoron concentrations and radon mapping was considered for years and several papers were published on the topic around the world [ 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 ], including in many Iranian cities [ 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 ] to increase public awareness of environmental radioactivity and to predict radon-prone areas, which would help authorities with regard to the development of an appropriate strategy to reduce public exposure to radon and thoron. This reduced exposure would increase the quality of life and improve public long-term health.…”

Estimates of the Lung Cancer Cases Attributable to Radon in Municipalities of Two Apulia Provinces (Italy) and Assessment of Main Exposure Determinants

“…A combined analysis of these studies [ 31 , 32 , 33 ], especially analysis of European studies [ 34 , 35 ], allowed the risk quantification. This quantification presents a linear relationship of risk with exposure, without a detectable threshold (stochastic effect), and is quantifiable in an increase of approximately 16% per 100 Bq/m 3 in the indoor radon concentration (excess of relative risk equal to 0.16, with a confidence interval 0.05–0.31) [ 36 ].…”