A large and feasible national survey representative of population exposure to outdoor gamma radiation in urban areas

Background

Although data on outdoor gamma radiation are available for many countries, they have generally been obtained with measurements performed in undisturbed environments instead of in urban areas where most of the population lives. Only one large national survey, with on-site measurements in urban areas, has been identified worldwide, probably due to high costs (e.g., personnel and instrumentation) and difficulties in selecting measuring points.

Methods

A campaign of outdoor gamma radiation measurements has been carried out in the entire Italian territory. All measurement points were selected at the infrastructures of an Italian telecommunications company as representatives of all the possible situations of outdoor exposure to gamma radiation for population in urban areas. Ten replicates of portable gamma (X) detectors carried out all the measurements.

Results

Approximately 4,000 measurements have been performed. They are distributed across 2,901 Italian municipalities, accounting for 75% of the Italian population. The national population-weighted mean of the gamma ambient dose equivalent rate (ADER) is 117 nSv h-1, and it ranges from 62 to 208 nSv h-1 and from 40 to 227 nSv h-1 for 21 regions and 107 provinces, respectively. The average variability at the municipal level, in terms of the coefficient of variation (CV) is 21%, ranging from 3 to 84%. The impact of land coverage and the distance from a building on the outdoor gamma radiation level was assessed with complementary measurements, leading to differences ranging from -40 to 50% and to 50%, respectively.

Conclusion

A representative campaign of outdoor gamma dose rate measurements has been performed in Italy, only in urban areas, to assess the exposure effect due to outdoor gamma radiation on the population. It is the largest national campaign in urban areas worldwide, with a total of 3,876 on-site measurements. The land coverage and the distance from surrounding buildings were recognized to strongly affect outdoor gamma radiation levels, leading to high variability within small areas. The collaboration with a company that owns a network of facilities on a national territory as dense as the residing population made this survey feasible and affordable. Other countries might adopt this methodology to conduct national surveys in urban environments.

Gamma radiation dose rate in high-altitude areas in the Bageshwar, Champawat and Pithoragarh districts of Uttarakhand, India

Radiation has a deteriorating effect on humans as well as on the environment depending on its level, although we have all been exposed to natural gamma radiation from birth. The presence of radionuclides in rocks, soil, plants, and water is a major factor behind the natural gamma radiation. The present study deals with the study of natural gamma radiation at Bageshwar, Champawat and Pithoragarh districts of Uttarakhand. It also consists of seasonal variations in gamma radiation and its relationship with altitude and geology. The purpose of this study was to investigate the influence of altitude and geology on natural gamma radiation dose rate data in high-altitude areas of India. The highest gamma radiation value was 444 nSv/h in the summer and 342 nSv/h in the winter. The investigation recorded the gamma radiation up to 2542.20 m altitude, indicating that the geology of the areas is more relevant than the altitude. Few sites in such a high-altitude zone were found to exceed the value of 200 nSv/h, as reported by UNSCEAR. This research is necessary in order to consider the human health and climate changes, both of which are part of the action plan for the United Nation's Sustainable Development Goals (SDG 3, SDG 13).

Gamma radiation dose rate distribution in the Anand, Bharuch, Vadodara, and Narmada districts of Gujarat, India

Radiation is present everywhere in the earth, and human beings are continuously exposed to gamma radiation. The health consequences of environmental radiation exposure are a serious societal issue. The purpose of this study was to analyse outdoor radiation in four districts of Gujarat, India: Anand, Bharuch, Narmada, and Vadodara during summer and winter seasons. This study illustrated the influence of lithology of areas on gamma radiation dose values. Summer and winter seasons are the primary factors that alter the causes directly or indirectly; therefore, the influence of season fluctuation on radiation dose rate was investigated. The annual dose rate and mean gamma radiation dose rate values from four districts were found to be greater than the global population weight average value. The mean value of gamma radiation dose rate from 439 locations in the summer and winter seasons was 136.23 nSv/h and 141.58 nSv/h, respectively. According to a paired differences sample study, the significance value between outdoor gamma dose rate in summer and winter seasons was 0.05 indicating that seasons have a significant impact on gamma radiation dose rate. The impact of various types of lithology on gamma radiation dose was studied in all 439 places, and the statistical analysis revealed that there was no significant association between lithology and gamma radiation dose rate in the summer season, but a relationship between lithology and gamma dose rate was observed in the winter season.

Impact of lockdown during COVID-19 pandemic on annual effective dose equivalent values of natural gamma radiation

The study aimed to determine the impact of COVID-19 on values of annual effective dose equivalent of the natural gamma dose rate of Balod, Durg and Bemetara districts of Chhattisgarh (India). COVID-19 is a severe problem for many countries and to control and prevent the spread of this problem, the lockdown approach has been implemented in many countries, including India. In this lockdown situation, almost all people stay at home for 24 h. Due to the present status of COVID-19, the Indian government also fixed the 67 days lockdown and one day was already successfully done as Janta Curfew, which worked the same as a lockdown. The value of indoor gamma dose rates was reported to be higher in most places compared to the outdoor gamma dose rate, but in this pandemic situation, occupancy factor values are not applicable as recommended by UNSCEAR for calculation of annual effective dose equivalent (AEDE). Therefore, the present study introduces the new equations, which can measure the extra AEDE value during lockdown for adults, children and infants.