Natural radioactivity is present everywhere in our life, it is part of the human environment.This phenomenon was discovered in 1896 by French scientist named Becquerel, who discovered the source of the natural radioactivity accidentally during the experiment to study the effects on the photographic plate, which was wrapped in black paper, a fluorescent zinc sulfide.
What is natural radioactivity?This transformation of atomic nuclei of chemical elements in the nuclei of atoms of another element.This process is always accompanied by radioactive radiation.Great contribution to the study of this issue has made an outstanding physicist Marie Sklodowska-Curie.It was she who in 1898 discovered the elements radium and polonium.
Physicists have shown that natural radioactivity is not subject to change under the influence of external conditions.It can be of two types: the proton and double-proton.
natural radioactivity in the composition comprises several components.These include: the cosmic radiation, radioactive substances, residing in the land, as well as a radiation source, which is in building materials, food and water.
If you calculate the percentage, the natural radioactivity can be represented as follows: 73% - due to the exposure to natural sources of radiation, which are ubiquitous around us, 13% - is created through medical procedures (the most significant largest X-ray), and 14% of the radiation falls on the rays from outer space.
Solar radiation has enormous power, but from the Earth it protects the environment, however, the greater the distance from the Earth's surface, the stronger the effect of cosmic radiation.Scientists have observed a doubling of its action after 1000 meters.For instance, during the flight of the aircraft when it climbs about 10 000 m, the radiation level in the cabin exceeds natural almost 10 times.
Flash, which periodically appear in the Sun, is also a powerful component of the "natural" background radiation.The following references - particles which are part of the construction materials from waste burning coal and phosphate fertilizers.
How distributed levels of natural radioactivity on the planet?Scientists have calculated that it varies in the amount of 5 -20 micro-roentgen per hour.This raises the question for humanity as a bad indicator for the life of the people inhabiting our planet.
on this issue ambiguous statements scientists.Some believe that the damage from radiation is negligible, while others argue that it causes severe disease and mutations, but it is quite obvious that this issue requires further study.
significantly affect the background radiation a person practically can not, so you need to protect themselves from the effects of those negative factors, which exceed the allowable values.
Units of radioactivity:
- 1 rem = 0.01 Sv;
- 1 mrem = 0.01 milli sievert.
Cosmic radiation is equivalent to an annual dose of 30 mrem (300 mSv), but, for example, at an altitude of about 10 km will be a dose 100 times greater.The level of radiation is different on different continents and in individual countries.In France, the US and Japan, it is 30 - 60 millirem per year.The population of these prosperous countries annually receives 100-150 mrem of radiation due to the existing background.In Russia, this figure averages 65 mrem / year.
Ways in which ingested radioactive substances can be very diverse.The most common of these are: the lungs, with food, through the skin by absorption.Increased radioactivity negative impact on the human body.Hazardous substances are evenly distributed throughout the body of the victim.If you take into account all sources of radionuclides, the annual dose for humans averages 135 millirem.
