Indoor radon concentration and its possible dependence on ventilation rate and flooring type

Abstract

The results of radon concentration measurements carried out in dwellings with natural ventilation for 1 y in Bangalore are reported. Measurements, covering three sessions of the day (morning, afternoon, night) were performed two times in a month for 1 y at a fixed place of each dwelling at a height of 1 m above the ground surface in selected dwellings. The low-level radon detection system (LLRDS), an active method, was used for the estimation of radon concentration. The measurements were aimed to understand the diurnal variation and the effect of ventilation rate and flooring type on indoor radon concentration. The geometric mean (± geometric standard deviation) of indoor radon concentration from about 500 measurements carried out in 20 dwellings is found to be 25.4 ± 1.54 Bq m⁻³. The morning, afternoon and night averages were found to be 42.6 ± 2.05, 15.3 ± 2.18 and 28.5 ± 2.2 Bq m⁻³, respectively. The approximate natural ventilation rates of the dwellings were calculated using the PHPAIDA--the on-line natural ventilation, mixed mode and air infiltration rate calculation algorithm and their effects on indoor radon concentrations were studied. The inhalation dose and the lung cancer risk due to indoor radon exposure were found to be 0.66 mSv y⁻¹ and 11.9 per 10⁶ persons, respectively. The gamma exposure rate was also measured in all the dwellings and its correlation with the inhalation dose rate was studied.

Indoor Radon Concentration and Ventilation Rate in Some Elementary Schools in Ibadan, Nigeria

“…This result is similar to n concentration and squared value of 0.77 indicates that ventilation rate is the key factor upon which radon concentration depends. This result is similar to that obtained by Ashok [11] where R squared value was gotten to be 0.66. Figure 3 is a bar chart that established inverse relationship between indoor radon concentration and ventilation rate.…”

The 222Rn and 220Rn concentrations in some dwellings of Mandya city and its surroundings, Karnataka, India

“…The lower concentrations of 222 Rn and 220 Rn in majority of dwellings may be attributed to the lower concentration of 226 Ra in the soil and building materials and also to the good ventilation condition in local dwellings. 30…”

Environmental assessment of radon levels in Cyprus

“…Although radon is found in low outdoor concentrations, it could concentrate in indoor areas such as residences, schools and workplaces, with radon progenyradon daughters (Figure 1) raising concerns for human exposure and public health risk. Particularly, in certain sites/buildings, radon may occur in high concentrations depending on the geological elements, the construction materials of buildings, the indoor atmospheric conditions, as well as the ventilation conditions of each building (Akbari et al, 2013;Ashok et al, 2012;Nero et al, 1986). Radon progenies are mainly deposited on the walls, and attach to small particles suspended in the atmosphere.…”