Outdoor dose rate mapping in Kuwait

Assessment of a naturally occurring high background radiation area with elevated levels of thorium along coastal Odisha, India using radiometric methods

The present study evaluates the enrichment and distribution of radioelements along the eastern coast of India. India possesses the second largest reserve of thorium bearing monazite in the world, in terms of heavy minerals present primarily along its long coastline. Radioelement estimation of about 30 km long beach area along the eastern coast of India is reported and implications discussed. A total number of 822 data points were studied using a portable Geiger Muller counter, to estimate the variation of dose rates, due to the ambient radionuclides along two different trends. One was parallel (northeast-southwest) and the second one perpendicular to the coastline. Pre-selected samples from in-situ radiometric surveys on the heavy mineral placers were studied further, for quantitative estimation of the abundance of radioactive elements primarily uranium and thorium, using a High Purity Germanium detector. Radioelement concentration assessment of core samples (depth ~2 m), were studied from two different beaches. Radiological parameters like radium equivalent, annual effective doserate and absorbed dose rate has been calculated based on the ²³⁸U, ²³²Th and ⁴⁰K concentrations. Heavy mineral placers along the shoreline indicate a very high thorium (avg - 2990.22 Bq kg^-1) which is due to the extensive distribution indicative of monazite. The coastal area also exhibits relatively low uranium (avg - 319.1 Bq kg^-1). Based on its high thorium concentration, the area can be considered as a high natural background radiation area. Based on the concentrations of uranium and thorium, the weathering conditions and depositional environment prevalent along the beach areas have been discussed.

ASSESSMENT OF THE OUTDOOR GAMMA RADIATION LEVELS IN ALGIERS PROVINCE, ALGERIA

The outdoor gamma radiation dose rates due to natural radioactivity and due to the artificial radionuclides released from the Chernobyl and Fukushima accidents and Algeciras incident were assessed in the Algiers province (capital of Algeria). Furthermore, the dose rates induced by the cosmic rays were analytically calculated in the province concerned. The recorded dose rates due to terrestrial outdoor gamma radiation were found to range from 14.3 ± 0.7 to 114.3 ± 5.7 nGy h -1, those due to cosmic rays ranged from 32.021 ± 0.013 to 34.029 ± 0.367 nGy h -1, while the contribution of the dose rate due to external exposure induced by 137Cs deposits, from major accidents, was estimated to be less than 0.3 nGy h-1. The spatial distributions of terrestrial and cosmic rays dose rates were mapped using QGIS software. The obtained radiological baseline maps can be used as reference information to assess any changes in the radiation exposure levels having an impact on the population health.

GAMMA DOSE RATES IN THE HIGH BACKGROUND RADIATION AREA OF MANGALORE REGION, INDIA

Elevated levels of natural background radiation due to scattered patches of monazite sand around the beaches of Mangalore, India, have been reported earlier. A comparative study of gamma dose rates was performed in both normal background and high natural background radiation areas around Mangalore using different types of portable gamma dosimeters. In addition to this, gamma-ray energy spectra were acquired, in situ, using a NaI(Tl) based portable gamma spectrometer. Soil and sand samples were collected for laboratory analysis with HPGe detectors. Measurements were carried out during the years 2016-18 revealed that in majority of the locations the gamma dose rates were similar to the normal background regions, whereas, in certain locations the dose rates were higher with values up to 530 nSv/h.