This study evaluates radon exhalation rates and assesses the potential radiological risks of external exposure to primordial radionuclides in building materials employed in the Ica region of Peru, particularly those with high uranium content. The radon exhalation rates are currently measured using a combination of a closed chamber and an active monitor. We proposed a novel method that effectively ensured a hermetic seal for the closed chamber and guaranteed that the efficient maintenance of secular equilibrium. The obtained results ranged from below the detection limit (BDL) to a maximum of 52.3 mBq · kg⁻¹h⁻¹. Gamma spectrometry was employed to measure the concentrations of radionuclides by utilizing a 3′ × 3′ NaI detector. The analysis of cement samples revealed a strong positive correlation between the activity concentration of radium and the radon exhalation rate. The activity concentrations for radionuclides varied, with values ranging from BDL to 60.6 mBq · kg⁻¹h⁻¹ for ²²⁶Ra, BDL to 22.3 mBq · kg⁻¹h⁻¹ for ²³²Th, and BDL to 1074 mBq · kg⁻¹h⁻¹ for ⁴⁰K. These findings contribute valuable insight to decision-making processes in the Peruvian construction industry, particularly regarding material safety and radiological risk management.

Radon is the main source of natural radioactivity, and its measurement is considered extremely important in radioprotection, given its relationship with the occurrence of lung cancer. In the last two years, measurements of this radioactive gas were carried out in Lima considering a grid of 5 km${}^2$ and the population density to determine the number of measurements to be carried out. Cellulose nitrate nuclear track detectors exposed in bare mode and diffusion chamber mode were used to estimate ${}^{222}$Rn concentrations. In diffusion chamber mode, non-commercial monitors and commercial monitors were used. The monitoring results are presented for 43 districts of the Lima Province whose population is approximately ten million inhabitants occupying a total area of 2655.15 km${}^2$. Measurements were made obtaining an average concentration of 49 Bq·m${}^{-3}$ using bare detectors and 66 Bq·m${}^{-3}$ using non-commercial diffusion chambers. Average concentrations obtained by both detector exposure modes were below the maximum concentration recommended by the WHO. A radon (${}^{222}$Rn) map was also obtained as a visual representation of the ${}^{222}$Rn levels in the Lima province using inverse distance weighting (IDW) interpolation.

The study investigated the radon emission rate and potential radiological hazards of high-uranium-content building materials in The Ica area of Southwestern Peru. We used a creative technique that combined a closed chamber and active monitor, and it was improved by a hermetic sealing method to maintain secular equilibrium well. The results showed radon emission rates as low as below detection limits (BDL) up to 52.3 mBq/kg•h. Our analyses with a 3' x 3' NaI detector found radionuclide concentrations in cement samples by gamma spectrometry. We found a high positive correlation between radium activity concentration and radon exhalation rate. The activity concentrations of 226 Ra, 232 Th, and 40 K differ significantly, with maximum values reaching 60.6, 22.3, and 1074 mBq/kg•h. We consider these results significant for the safety of materials in the Peruvian construction sector. And we also hope that they will provide information to support radiological risk management.