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How to Measure Radiation

Radiation Exposure

People are naturally exposed to different levels and types of radiation as they go about their day. Some examples include x-rays and other medical procedures, radioactive materials found in the soil, and cosmic rays that come from space. One year of natural radiation exposure typically equates to 300 mrem 3 mSv, the units of which will be explored upon further in the next section of this article.

The small amounts of radiation that people are regularly exposed to typically don’t result in either short or long-term health effects. Still, it’s essential to stay safe and know what to do in the event of excessive exposure to large amounts of radiation. Those who are experiencing acute radiation syndrome (ARS) with symptoms of nausea, burns, or vomiting shortly after radiation exposure should receive professional medical attention as soon as it is safe to do so. 

Related: Radiation Mutation: How Radiation Affects DNA

Radiation Units of Measure

A doctor examining an X-ray.

While most scientists within the international community utilize the System International (SI) to measure radiation, conventional radiation measurement systems are still used widely within the United States.

Different aspects of radiation can be measured, and as such, different units are used to measure those specific aspects. For instance, when measuring radioactive material, scientists will either use the curie (Ci) unit of measurement or the SI unit known as becquerel (Bq). The conventional unit rad and the SI unit gray (Gy) are used to measure the dosage of radiation absorbed by a person. Finally, the biological risk of radiation exposure is measured with the conventional unit of rem or the SI unit known as sievert (Sv).

Related: The Effects of Radiation On The Body

Radiation Measurement Abbreviations

If the amount of radiation being measured is less than 1, prefixes are added to the unit of measure being used as a form of shorthand. For example, when the radiation measure is .01, the abbreviation for centi (c) is put before the unit. In the case of the SI unit Sv, the radiation measurement would be written as cSv. When the radiation level equates to .001, the abbreviation for milli (m) is put before the unit. In the case of the conventional unit Ci, the radiation measurement would be written as mCi

Abbreviations for micro (µ), nano (n), pico (p), femto (f), and atto (a) are also utilized in tiny measurements of radiation.

When the amount of radiation is measured at 1000 or greater, other prefixes and abbreviations are used. Kilo (k) would equate to a radiation measure of 1000, mega (M) equates to 1,000,000, and giga (G) equates to 1,000,000,000. Other prefixes for large measures of radiation include tera (T), peta (P), and exa (E).

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Measuring Radiation Emissions 

Atoms can emit radioactivity when their nucleus has too many particles, too much mass, or too much energy to remain stable. When this happens, the atom’s nucleus will break down or begin to disintegrate and release energy to reach a steady, nonradioactive state. The energy that the nucleus releases come in the form of radiation. 

When discussing radiation emission, either the conventional unit Ci or the SI unit Bq is used.  These units communicate the number of radioactive atoms in a piece of radioactive material over a specific period. Ci and Bq are also used in reference to the amount of radioactive material released into the environment due to a particular event or various types of human activity.

One Ci is equivalent to 37 billion disintegrations per second, and one Bq is equal to one disintegration per second.

Measuring Doses of Radiation

A person wearing a gas mask.

When an individual is exposed to radiation, the energy is taken in by the body’s tissues. The amount of energy taken into the body per the weight of human tissue is referred to as the absorbed dose. Absorbed doses are measured using the conventional unit rad (radiation absorbed dose) or the SI unit Gy. One Gy is equivalent to 100 rad.

Related: Radiation Badge Monitoring: The Ultimate Guide

Measurement of Biological Risks

The biological risk of radiation exposure is measured via the conventional unit of rem or the Sv SI unit, and it refers to the risk that a person may suffer health effects due to radiation exposure. In order to determine a person’s biological risk, scientists have assigned a different number to each type of radiation that one can be exposed to and that type’s ability to transfer and deposit energy into the cells of the body. These include alpha and beta particles, x-rays, and gamma rays. This number is known as the Quality Factor (Q).

If a person is exposed to radiation, scientists can multiply the dose in rad by the quality factor for the radiation type involved. Doing this allows them to estimate a person’s biological risk in the unit of rem. One Sv is equivalent to 100 rem.

Additional Information

If you’re looking to know more about radiation and radiation emergencies, please feel free to examine the Center for Disease Control and Prevention’s (CDC) Radiation Emergencies Website to find out how to protect yourself and your loved ones.

You can learn about self-decontamination, evacuation procedures, radiation containment and exposure, food and drinking safety during a radiation emergency, radiation injuries and illness, along with additional health information for those belonging to high-risk groups. 

Want to know how to detect and protect yourself from radiation and its harmful effects? Reach out to Med-Pro today and learn what they can do for you.

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