| Session Details | |
| Section | IG - Interdisciplinary Geosciences |
| Session Title | Geo-Hazards due to Presence of Natural Radionuclides in Normal and High Background Radiation Areas |
| Main Convener | Prof. R.C. Ramola (H.N.B. Garhwal University, India) |
| Co-convener(s) | |
| Session Description | Natural radioactivity in the environment and its causing agents are drawing the attention of world community and are of importance due to the toxicity and risk of lung cancer. Uranium and thorium are naturally occurring radiotoxic trace element, present in minute amount in almost all rocks, sand, soil, and water, etc. Building materials are commonly derived from the natural materials, which contain traces of U-238, Th-232 and K-40 . Although these elements occur in virtually all types of rocks and solids, their concentration vary with specific sites and geological materials. Radon, being an inert gas can move freely through the soil from its source and has a half life of 3.8 days which is long enough, allowing a part of it to diffuse from the soil and building materials to inside atmosphere of the dwellings. During recent years, radon/thoron monitoring has become a global phenomenon due to its health hazard effects on population (radiation workers and general public). It has been estimated that out of 2.2 mSv of dose, which an individual receives annually from low-level exposure, 1.27 mSv is due to radon isotopes and their short-lived progeny. As the radon/thoron contributes the largest fraction of the natural radiation dose to populations, tracking its concentration is thus of fundamental interest from radiation protection, health and hygiene point of view (whether in mining developments, coal fields, thermal power plants, housing, building construction materials etc.). Dose from the inhalation of radon in dwellings is more than that from all other natural radiation sources. The estimated level of health risk associated with average indoor radon/thoron levels is much higher than those due to other environmental carcinogen. Despite of extensive knowledge of radiation risks gained through epidemiologic investigations and mechanistic considerations, the health effects of chronic low-level radiation exposure are still poorly understood. The invited talks and presentations will review the possible contribution of studies of populations living in high natural background radiation (HNBR) areas, including radon-prone areas, to low dose risk estimation. It will contribute to a deeper understanding of natural radiation and in particular of its human radiation exposures. The session will cover the following themes: •Measurements and behaviour of natural radionuclides in human environment •Assessment of health hazard effects of radon and other natural radionuclides •Regulatory aspects of natural radiation exposure. |