An overview on measurements of natural radioactivity in Malaysia

Abstract

NaISoil Radioactivity a b s t r a c t Humans are always exposed during their lives to ionizing radiation arising outside and within the earth. The exposure to these radiation occurs from natural sources such as radioactive elements in rocks and soil, internal exposure form radioactive elements through water, food and air and cosmic rays entering from outer space to earth's atmosphere. About 87% of the radiation dose received by human beings is due to natural radiation, it is essential to assess the radiation doses in order to control possible health effects from such natural sources. In this regard, a number of articles have been appeared for Malaysia in international research journals, which have been reviewed and complied in this article. Most of these articles are about the measurement of activity concentrations of primordial ( 238 U, 232 Th, 226 Ra and 40 K) and anthropogenic ( 137 Cs) radionuclide's and gamma dose rate in environmental samples using HPGe and NaI (Tl) survey meter.

Natural Radioactivity Levels of Agricultural and Virgin Clay Soil Samples at Al Najaf Governorate

“…The natural radionuclides were determined in (20) agricultural and virgin, Soils samples collected from (4) different regions in Najaf province as shown in table (1). Three types of soil were collected at depth (0-50) cm from farms and virgin.…”

“…Three types of soil were collected at depth (0-50) cm from farms and virgin. The samples dried at (100ºC) for 24 hours in oven as shown in figure (1). the containers were washed with dilute hydrochloric acid and rinsed with distilled water.…”

“…Only nuclides with half-lives comparable with the age of the earth and present in terrestrial materials such as 232 Th, 238 U, and 40 K are of great interest as they cause external and internal hazards because of gamma ray emissions [1]. We currently live in a world of radionuclide's, where we inhale and ingest these radioactive substances daily in the form of food, water, and air as no place on the earth is free of radioactivity [2].…”

Environmental radiology assessment in Lahad Datu, Sabah

“…Human beings were estimated to receive about 87% natural radiation. Therefore, it is important to assess environmental radiology for health and safety purpose [2].…”

“…The probability of the risk of cancer , Gr is estimated by using equation (2). The risk factor, R is 0.05 Sv -1 and H is the AEDE value [13].…”