Naturally Occurring Radioactive Materials
On daily basis, we are constantly exposed to the Naturally Occurring Radioactive Materials. Though in Building Biology, we deal with building materials that are emit low-radiation, they are installed across larger areas in greater quantities. Natural sources of radio-active materials like Thorium-232, Potassium-40 & Radium-226 become accumulated in natural stones, building materials & industrial products, depending upon their origin of mining & production process.
The effects of radioactivity vary substantially from material to material, but even with a single type of material, great dose variation may occur leading to its greater effect. Particularly, the silicone-rich magmatic rocks- especially granite - show a relatively higher content of natural radionuclides, among the building materials that come from natural origin.
The increase in the usage of granite has been a growing concern. Indoor Environmental Connections, Oct 2009 Publishment stated “Health physicists and radiation experts generally agree that most granite countertops emit radiation and radon at extremely low levels. They say these emissions are insignificant compared to so-called background radiation that is constantly raining down from outer space or coming up from the Earth's crust, not to mention man-made sources like X-rays, luminous watch dials, and smoke detectors.”. It is difficult for most people to gauge the radiation levels from granite since it is complex & needs equipment that are expensive.
Industrial manufacturing processes are known to generate waste products, that can also gather radioactive substances. These substances are sometimes used as secondary raw materials in building work, in cases of improper usage. Hence, unknowingly, the general public gets exposed to these elevated radioactive substances, that cause harm. In today’s globalisation time, where the waste products are being reused at a larger level, it is of utmost importance to trace down these sources that have radioactive substances.
Lime, lime sandstone, natural gypsum, pure cement, aerated concrete, wood, gypsum from flue-gas desulfurization (FGD gypsum), most plastering materials as well as all types and mixtures of concrete seldomly depict elevated radiation levels. As a precaution, it is recommended to test the bricks, brick products, clinker bricks and other natural stones & ceramic tiles for their radioactivity, since these are also peculiar in exhibiting elevated levels of radioactivity in exceptional cases besides pumice, basaltic rocks, slag, many industrial products, ashes (PFA pulverized fuel ashes), certain types of tuffs and synthetic gypsum such as phosphogypsum.
Hence, it is of utmost importance to be informative of the Naturally Occurring Radioactive Materials, since ignorance towards them may lead to a long-term effect on health.
