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Item type:Publication, An approach to the measurement of radon permeability and transmission factor using Cr-39 detectors inside a diffusion chambers exposed in a new-build radon chamber(RELX Group (Netherlands), 2022-01-01)Many CR-39 (poly allyl glycol carbonate) detectors inside two different diffusion chambers were used to study the radon permeability and the radon transmission factor. This factor represents the percentage of radon concentration that truly enters a diffusion chamber, since there is a loss of radon concentration inside the chamber compared to the outside radon concentration, due to the radioactive nature of radon gas. Here, a theoretical discussion is presented, followed by an experimental study that was carried out in a new-build radon chamber. These initial results are presented in order to check the reliability of the radon chamber. The most remarkable observation is that research consistently shows that the obtained value of radon permeability constant for a commercial membrane is 4.404×10 − 8±0.012×10 − 8cm2/s, which is in a good agreement with literature data. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Comprehensive study of natural radioactivity in building materials: A case study in Ica, Peru(Multidisciplinary Digital Publishing Institute (MDPI), 2024-03-01)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. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Variations in air pollution before, during and after the COVID-19 lockdown in Peruvian cities(Springer Science and Business Media Deutschland GmbH, 2024-11-01)The high concentrations of air pollutants in Peru remain a persistent problem, significantly impacting public health. Understanding the extent to which the COVID-19 lockdown affected these contaminants is crucial. To determine variations in NO2, O3, CO, and SO2 concentrations in 10 Peruvian cities before, during, and after lockdown. A comparative ecological study was conducted in urban areas of 10 major Peruvian cities using the Google Earth Engine (GEE) platform. Data on atmospheric pollutant concentrations were extracted from the Sentinel-5P/TROPOMI satellite images for the period between March 16 and June 30, across the years 2019, 2020, 2021, and 2022, for comparative analysis. The Wilcoxon test was used to evaluate changes between the study periods. We included 10 urban cities located across three geographic regions of Peru. Most urban cities experienced a decrease in NO2 concentrations and an increase in O3 and CO levels during the lockdown, while SO2 concentrations remained relatively constant. The lockdown has caused variations in NO2, O3 and CO concentrations. Future studies with accurate data on air pollutant concentrations are needed to ensure targeted and effective interventions. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Preliminary Applications Carried Out in a New-Build Radon Chamber Using CR-39 Detectors Inside Non-Commercial Diffusion Chambers(Elsevier Ltd, 2023-06-01)Many CR-39 (poly allyl glycol carbonate) detectors inside two different non-commercial diffusion chambers were used to study the radon permeability and the radon transmission factor. This factor represents the percentage of radon concentration that truly enters a diffusion chamber, since there is a loss of radon concentration inside the chamber compared to the outside radon concentration, due to the radioactive nature of radon gas. Here, a theoretical discussion is presented, followed by an experimental study that was carried out in a new-build radon chamber. These initial results are presented in order to show a preliminary performance evaluation of the radon chamber as well as introducing some preliminary applications. The most remarkable observation is that research consistently shows that the obtained value of radon permeability constant for a commercial membrane is 4.404×10−8±0.012×10−8cm2/s, which is in a good agreement with literature data. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Estimation of Indoor 222Rn Concentration in Lima, Peru Using LR-115 Nuclear Track Detectors Exposed in Different Modes(Multidisciplinary Digital Publishing Institute (MDPI), 2023-06-01)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 (Formula presented.) 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 (Formula presented.) 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 (Formula presented.). Measurements were made obtaining an average concentration of 49 Bq·m (Formula presented.) using bare detectors and 66 Bq·m (Formula presented.) using non-commercial diffusion chambers. Average concentrations obtained by both detector exposure modes were below the maximum concentration recommended by the WHO. A radon ((Formula presented.) Rn) map was also obtained as a visual representation of the (Formula presented.) Rn levels in the Lima province using inverse distance weighting (IDW) interpolation. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Environmental Alpha Radiation from the Soil at a Prehispanic Ancient Sacred Site in Lima, Perú(Polskie Towarzystwo Inzynierii Ekologicznej (PTIE), 2023-01-01)In the present work, we investigate the concentration of radon and its alpha-emitting progeny at the archaeological site of Huaca 20 in Lima, Peru. The site holds significant cultural and historical importance as an ancient pre-Inca ruin, providing valuable insights into the lives and rituals of its former inhabitants. We quantified the radon levels accurately with passive CR-39™ detectors deployed within specially designed chambers at the site for 28 days. In a controlled laboratory environment, we processed the detectors afterward, examining and analyzing the resulting tracks using advanced microscopy and the ImageJ analysis software. The ground-level concentration of radon and its alpha-emitting progeny was determined, revealing elevated levels ranging from 2.4 ± 0.6 to 8.9 ± 0.9 (kBq/m3). These findings underscore the unique presence of radon at Huaca 20 and highlight the potential impact on microorganisms at ground level. Likewise, these results can contribute to studies on the radiological risks faced by visitors, excavators and archaeologists. Finally, we show the spatial distribution of radon concentrations within the site by creating an iso-concentra-tion map. The iso-concentration map reveals a relation between areas with elevated radon levels and the good preservation of funerary contexts.