In recent decades, an important role in the construction industry began to play construction biology, the science of the impact of construction on humans and the environment. Previously, they practically did not pay attention to this, but according to modern requirements, the amount of substances hazardous to human health should be minimized in building materials. The presence and content of asbestos, formaldehyde, etc. are strictly controlled.
A separate point in building biology is the radioactive background of building materials. Indoors, a person is somehow exposed to more radioactive effects than outdoors, all other things being equal. The degree of this effect directly depends on the type and origin of the surrounding building materials. The most natural radioactivity is possessed by stones of volcanic origin: pumice, granite, etc. High radioactive background is shown by materials recycled from industrial waste: slag concrete, slag, slag Portland cement. Chemical gypsum obtained from waste may also have high radioactivity.
Natural gypsum has one of the lowest levels of radioactivity - 29 Bq / kg. Phosphogypsum, also widely used in construction, has a higher rate of 574 Bq / kg. Possessing much greater specific radioactivity than the natural gypsum that it was intended to replace, phosphogypsum exposes people to more intense radiation (30%). The content of radioactive elements in phosphogypsum depends on their concentration in phosphate raw materials, therefore, the radioactivity of phosphogypsum should be measured and taken into account in each case when choosing a storage location and to determine the possibilities of its use.
Radionuclides are small particles that can spread in the air in the form of dust. According to a study by Indian ecologists, radionuclides of uranium-238 and radium-226 are often present in phosphogypsum and the surrounding air, getting into the respiratory tract of people and animals and settling in water bodies and agricultural areas. Radon-222, the decay product of radium-226, has a gaseous form, and therefore can be transported through the air by diffusion.
The topic of the negative impact of phosphogypsum on humans and the environment is currently becoming increasingly important, ways to solve the problems are being sought. The Atomic Energy Regulatory Council (AERB) has already issued a directive on the safety of the use of phosphogypsum, but not all manufacturers of gypsum building materials take it into account in their work. Although it is not possible to completely abandon harmful materials in the near future, ecologists and construction biologists recommend, if possible, to use only natural gypsum for living quarters in combination with other natural materials.