Detecting and Measuring Ionizing Radiation


A human body has been equipped with multiple sense organs by virtue of evolution, but none of them is capable of detecting the presence of radiation in a natural or closed environment. However, many times the radiation can be “felt” and the signs can easily be mistaken for a paranormal presence.

Sun rays are one of the most familiar forms of radiation. Light, heat and sound, all are types of radiation. But the radiations we need worry about are called ionizing radiation. It can produce charged particles (ions) in a matter, causing damage to its molecular structure. Similarly, the structure of living tissues and even the DNA can get altered by the radiations making it extremely dangerous, at high levels of exposure.

Why do you need to Detect Ionizing Radiation?

Nowadays a lot of places and even residential areas are contaminated with radionuclides due to human intervention. Ionizing radiations are measured in the unit millisievert or mSv. There are different routes via which ionizing radiation can affect you:

Internal exposure to ionizing radiation occurs when a radionuclide is inhaled, ingested or enters into the bloodstream via different routes (like wounds).

External exposure may occur when airborne radioactive material is deposited on skin or clothes. It can then penetrate through the skin if not removed soon.

If the radiation dose is low and/or it is delivered over a long period of time (low dose rate), the risk is substantially lower because there is a greater likelihood of repairing the damage. The relationship between the health effects of exposure with time is linear, though a different range of radiation can have severe effects on people:

  • Even in low dose rate there is a risk of long-term effects such as cancer, which can appear in years or even decades later.
  • Epidemiological studies on populations exposed to radiation showed a significant increase of cancer risk at doses above 100 mSv.
  • Some epidemiological studies even suggested the increase in risk of cancer to individuals exposed to medical exposures during childhood (pediatric CT) even at lower doses (between 50-100 mSv).
  • The risk is higher for children and adolescents as their tissues are still in the development stage.
  • Prenatal exposure to ionizing radiation may induce brain damage in fetus after an acute dose exceeding 100 mSv between weeks 8-15 of pregnancy and 200 mSv between weeks 16-25 of pregnancy.
  • Studies indicate that after fetal exposure to radiations the risk of cancer is similar to that of the risk during early childhood exposure.
  • Beyond a certain threshold (1000 mSv for acute radiation syndrome), it can impair body functions right away. The symptoms may manifest itself in the form of skin redness, hair loss or radiation burns.

The main problem with ionizing radiation is that it can’t be seen or detected without using tangible and sophisticated equipment. People receive some small doses of radiation from natural sources every day which does not harm our bodies. Refer to the graph below for annual radiation doses from natural sources in different countries.

The inability of human senses to detect ionizing radiations makes it inevitable to use tools that can detect and measure safe levels of ionizing radiations in surroundings.

How to detect and measure Ionizing Radiations

With time and technological advancement there are plenty of radiation detectors easily available in the market nowadays. However, not all of them are suitable for your household usage. Some specific radiation detectors can only shield you from certain radiations and not provide an all round safety for you and your surroundings. Some ways to detect and keep your exposure levels minimum:

1. Using simple and popular monitoring devices: Geiger counter is the most widely used radiation detection equipment. Though it cannot tell the difference between the varieties of radiation and its toxic effects, but you can gauge the level of radiation in an already exposed zone. It shows readings in the form of mR/hr or microSv/hr on an LCD screen.



2. Modernized Ionization Chambers: These precisely built chambers give an exhaustive list of the types of radiations plaguing your work environment. They can detail the radiation levels within its perimeter but their use is especially limited because of their low sensitivity.

3. Survey monitors: These types of monitoring equipment are being widely used by municipalities and militaries for their moderately high sensitivity and affordable prices. They can distinguish between different types of radiation at a site by emitting light of different wavelengths (colors). There are some areas of the lab which might be a little difficult to reach or examine for nuclear radiation. These corners need special equipment which is slim, sensitive and accurate. And in similar situations a survey monitor comes to the rescue. They are not just versatile and portable but also very easy to use. The integrated LED detector and LCD display make them the instrument of choice for lab personnel as well.

Survey monitors

4. Personal Radiation Detectors (PRDs): When entering high radiation zones one must not forget to strap on a PRD. These dosimeters are so accurate that they are used for the measurement of medical doses as well as industrial purposes. It can measure the amounts of ionizing radiations in the environment including X-rays and neutron radiations. Though they are not very portable, but they provide a level of accuracy which the earlier mentioned devices can only dream of achieving. However, Ecotest has made very fine and pocket-friendly dosimeters as shown below.

Ionizing radiations can silently kill living cells in your body and gradually turn them cancerous. Though low doses of radiations do not do much harm, but you must ensure that the limit is indeed safe!


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