Measuring Doses Of Radiation
When an individual is exposed to radiation, the energy is taken in by the bodys 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 or the SI unit Gy.One Gy is equivalent to 100 rad.
Radiation Units Of Measure
While most scientists within the international community utilize the System International 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 unit of measurement or the SI unit known as becquerel . The conventional unit rad and the SI unit gray 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 .
Related: The Effects of Radiation On The Body
Strength Of Emf Radiation
When you hear discussionsrevolving around the dangers of EMF radiation, they are essentially referringto its strength. The most common units used to measure this includes Volts,Watts, and Gauss.
The preference for one unit overthe other depends on several factors, such as the type of EMF radiation youremeasuring, the medium, the frequency of the given radiation, and the specificpart of the world youre in.
The next section looks at whatunits of measurement you should expect with regard to the three different typesof EMF radiation.
Recommended Reading: Icd10 History Of Breast Cancer
What Units Are Used For Measuring Radiation Exposure
X-ray and gamma-ray exposure is often expressed in units of roentgen . The roentgen unit refers to the amount of ionization present in the air. One roentgen of gamma- or x-ray exposure produces approximately 1 rad tissue dose and rad units of dose).
Another unit of measuring gamma ray intensity in the air is “air dose or absorbed dose rate in the air” in grays per hour units. This unit is used to express gamma ray intensity in the air from radioactive materials in the earth and in the atmosphere.
Appendix : Units Of Radiation
Units of Activity
|SIunit defined as the quantity of radioactive material in which one atomis transformed per second, or one disintegration per second .
|Older unit defined as the activity of radioactive material in which the nuclei of 3.7 x 1010 atoms disintegrate per second or 2.2 x 1012 disintegrations per minute .
Units of Radiation Exposure
The coulomb/kilogram is the SI unit used to measure the radiation-induced ionizations created in a unit mass.
Theroentgen is the old unit defined as the quantity of radiation thatproduces ions carrying one statcoulomb of charge per cubic centimetreof air at 0oC and 760 mm Hg. The milliroentgen is a commonly usedunit for the display or readout on survey meters and portable detectionunits.
Units of Absorbed Dose
The gray is the SI unit used to measure the energy imparted to irradiatedmatter and is defined as the absorbed radiation dose of one joule per kg.
The rad is the old,but still commonly used unit, defined as an absorbed radiation dose of100 ergs/g or 0.01 J/kg.
Units of Relative Biological Effectiveness
Recommended Reading: How Long Does Radiation Last In An Area
What Is A Committed Dose
When a radioactive material gets in the body by inhalation or ingestion, the radiation dose constantly accumulates in an organ or a tissue. The total dose accumulated during the 50 years following the intake is called the committed dose. The quantity of committed dose depends on the amount of ingested radioactive material and the time it stays inside the body.
Consider Where You Spend A Large Portion Of Your Time
The adverse effects of EMFradiation on an individuals health dont manifest immediately. It iscumulative. This means that your risk of developing radiation-related ailmentsincreases with continued exposure throughout your lifetime.
For this reason, you need to be mindfulof the places where you spend a large portion of your time and measure theamount of radiation in those areas. Some starting points include:
- Where you work
- What you use to getaround more so, if you have a long commute
- Your favorite readingspot in your home or coffee shop
If you find unusually high readings that could pose a health risk with continued exposure, it might be time to change things up a bit.
You May Like: Cold Caps For Chemo Patients
Emission Of Multiple Types Of Emf Radiation
Many household appliances emit more than one type of EMF. For instance, if you have an induction cooktop in your kitchen or a hairdryer , theres a good chance that they will be generating both magnetic-field as well as electric-field radiation.
If youre working on your laptopwhile its connected to Wi-Fi, theres a strong likelihood that it is emittingcopious amounts of radio-frequency radiation, magnetic field radiation, andelectric field radiation.
So, its important to configureyour EMF meter to different settings to get a clear picture of the levels ofthe various kinds of radiation different devices areemitting.
Development Of The Absorbed Dose Concept And The Gray
Wilhelm Röntgen first discovered X-rays on November 8, 1895, and their use spread very quickly for medical diagnostics, particularly broken bones and embedded foreign objects where they were a revolutionary improvement over previous techniques.
Due to the wide use of X-rays and the growing realisation of the dangers of ionizing radiation, measurement standards became necessary for radiation intensity and various countries developed their own, but using differing definitions and methods. Eventually, in order to promote international standardisation, the first International Congress of Radiology meeting in London in 1925, proposed a separate body to consider units of measure. This was called the International Commission on Radiation Units and Measurements, or ICRU, and came into being at the Second ICR in Stockholm in 1928, under the chairmanship of Manne Siegbahn.
The adoption of the gray by the 15th General Conference on Weights and Measures as the unit of measure of the absorption of ionizing radiation, specific energy absorption, and of kerma in 1975 was the culmination of over half a century of work, both in the understanding of the nature of ionizing radiation and in the creation of coherent radiation quantities and units.
The following table shows radiation quantities in SI and non-SI units.
Recommended Reading: When Does Hair Start Growing Back After Chemo
Development Of Replacement Radiometric Quantities
Although a convenient quantity to measure with an air ion chamber, the roentgen had the disadvantage that it was not a direct measure of either the intensity of X-rays or their absorption, but rather was a measurement of the ionising effect of X-rays in a specific circumstance which was dry air at 0 °C and 1 standard atmosphere of pressure.
Because of this the roentgen had a variable relationship to the amount of energy absorbed dose per unit mass in the target material, as different materials have different absorption characteristics. As the science of radiation dosimetry developed, this was seen as a serious shortcoming.
In 1940, Louis Harold Gray, who had been studying the effect of neutron damage on human tissue, together with William Valentine Mayneord and the radiobiologist John Read, published a paper in which a unit of measure, dubbed the “gram roentgen” defined as “that amount of neutron radiation which produces an increment in energy in unit volume of tissue equal to the increment of energy produced in unit volume of water by one roentgen of radiation” was proposed. This unit was found to be equivalent to 88 ergs in air. In 1953 the ICRU recommended the rad, equal to 100 erg/g, as the new unit of measure of absorbed radiation. The rad was expressed in coherent cgs units.
Activity: How Much Radiation Is Present
Radioactive material is usually not described in terms of its mass or volume. Instead, the amount of radioactive material present is communicated in terms of how quickly the material decays, or its activity. In the International System of units , the unit of activity is the becquerel . A becquerel is one decay per second .
The curie is the traditional unit of radioactivity and is the unit most commonly used in the United States. One curie is 37 billion Bq. Since the Bq represents such a small amount, you are likely to see a prefix used with Bq, as shown below:
A large amount of material can have a very small amount of radioactivity a very small amount of material can have a lot of radioactivity.
For example, uranium-238 has 0.00015 curies of radioactivity per pound , while cobalt-60 has nearly 518,000 curies per pound.
In the International System of units , the becquerel is the unit of radioactivity. One Bq is 1 disintegration per second .
Also Check: Is Chemo Or Radiation Worse
What Is Ionizing Radiation
Ionizing radiation is radiation that has enough energy to remove electrons from atoms or molecules when it passes through or collides with some material. The loss of an electron with its negative charge causes the atom to become positively charged. The loss of an electron is called ionization and a charged atom is called an ion.
Note: Microwave, infrared and ultra-violet radiation are examples of non-ionizing radiation. Non-ionizing radiation does not have enough energy to remove electrons.
Radiation Units And Limits
The concept of activity is used as the measure of radioactivity. The activity is the average number of radioactive transformations of definite nuclei per unit time. The measurement unit of the activity is becquerel the activity of 1 Bq is correspondent to one transformation of a radionuclide in one second.
The concept of activity is used as the measure of radioactivity. The activity is the average number of radioactive transformations of definite nuclei per unit time. The measurement unit of the activity is becquerel the activity of 1 Bq is correspondent to one transformation of a radionuclide in one second. There is also off-system unit of activity named curie 1 Ci = 3,7×10¹º Bq.
To measure the emittance of contaminated surfaces one uses the concept of flux density. This is the number of particles that cross the unit area normally to it per unit time. The flux density unit – 1/, that is such flux density when one particle traverses during 1 second the area of 1 m².
To measure the impact of ionising radiation the absorbed dose concept is used. This is the average energy imparted to matter. The absorbed dose unit is gray 1 Gy is referred to absorption o 1 J of ionising radiation energy by 1 kg of matter.
Absorbed dose rate specifies the intensity of the radiation impact on matter the rate of 1 Gy/s is correspondent to absorption of the radiation energy of 1 J by 1 kg of matter in 1 second.
Don’t Miss: Best Gummies For Chemo Nausea
What Are Some Examples Of Ionizing Radiation
There are natural and artificial sources of ionizing radiation. Artificial sources of radiation include X-ray machines, radioactive isotopes used in nuclear medicine, gamma cameras, nuclear gauges and nuclear power plants.
X-rays refer to a kind of electromagnetic radiation generated when a strong electron beam bombards metal inside a glass tube. The frequency of this radiation is very high – 0.3 to 30 Ehz . By comparison FM radio stations transmit at frequencies around 100 MHz or 0.1 Ghz .
Natural sources of radiation include:
- background radiation from space,
- cosmic radiation from cosmic rays,
- terrestrial radiation from minerals in the earthâs crust,
- radiation from inhaling radon gas,
- radiation from ingesting food and drinking water that may contain radioactive potassium-40.
Minerals such as uranium and thorium are radioactive and give off radiation when the nucleus breaks down or disintegrates. The three kinds of radiation generated by radioactive materials or sources are alpha particles, beta particles and gamma-rays.
What Are The Limits Of Exposure To Radiation
The Threshold Limit Values published by the ACGIH are occupational exposure limits adopted by many jurisdictions as guidelines or legal limits:
20 mSv – TLV for average annual effective dose for radiation workers, averaged over five years
In Canada, the Radiation Protection Regulations set radiation exposure limits for the public and nuclear energy workers.
The annual effective dose limit is 1mSv for the Canadian public. This dose limit aligns with the International Commission on Radiological Protection recommended annual dose limit of 1 mSv for the general public.
Based on information from regular monitoring of the most exposed workers, such as a radiographer, shows that the average annual doses are 5 mSv per year.
Also Check: Best Radiator For 6.0 Powerstroke
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 persons biological risk, scientists have assigned a different number to each type of radiation that one can be exposed to and that types 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 .
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 persons biological risk in the unit of rem. One Sv is equivalent to 100 rem.
What Is The Best Unit For Measuring Radio
Theres no definitive answer tothis question. However, if youre looking to protect yourself against EMFs,then the recommended unit of measurement would be volts per meter . Thereare two main reasons for this.
First, if you dont have ascientific background, V/m is fairly straightforward to understand. Its theeasiest way to measure the pulsing effects of radio-frequency radiation, whichis considered by most people to be the most detrimental form of EMF.
Second, and equally as important,most EMF meters give their measurements in V/m. So, it would be quite pointlessto measure EMF radiation in one unit and then go through the hassle ofconverting the readings to establish whether they are within acceptable levels.However, if you have to, heres how to go about it.
Don’t Miss: Best Cancer Treatment Centers In The World
How To Measure Emf Radiation: The Basics
Before getting into the units formeasuring EMF radiation, its important to have a general overview of whatexactly it is in the first place. An EMF is essentially a physical field thatsproduced by an electrically charged object. It is broadly classified into threemajor categories:
- Electric fields
- Magnetic fields
Exposure to EMF radiation over sustained periods has long-lasting adverse biological effects on the human body. Youll be surprised by the number of ways youre exposed to EMF radiation in your day-to-day life.
For instance, the smartphone orPC youre reading this guide on is emitting radiation. If you heated someleftovers in your microwave, you were exposed to radiation. Theres no escapingit. Ultimately, what matters is that youre not exposing yourself to highamounts of it over long periods.
EMF is often measured by itsstrength and frequency. So if you come across terms like ELF or UHF , they simply refer to the particularregion of the EM spectrum that the radiation falls in.
What Are The Main Ways To Control Radiation Exposure
The main ways to control radiation exposure include engineering controls, administrative controls and personal protective equipment. Examples of these controls include:
- Education and training
= 1 WL exposure for 170 hours
1 WLM = 3.5 mJ-h/m3
Often people use the concentration of radon gas in the air to estimate the WL level of radon daughters. Such estimates are subject to error because the ratio of radon to its decay products is not constant.
Equilibrium factor is the ratio of the activity of all the short-lived radon daughters to the activity of the parent radon gas. Equilibrium factor is 1 when both are equal. Radon daughter activities are usually less than the radon activity and hence the equilibrium factor is usually less than 1.
mJ-h/m3 = millijoule hours/per cubic metre
MBq-h/m3 = megabecquerel hours per cubic meter
Joule is unit of energy
1 J = 1 Watt-second = Energy delivered in one second by a 1 Watt power source
1 calorie = 4.2 J
MBq/m3 = megabecquerel per cubic metre
WLM = Working Level Months
Recommended Reading: Gifts For Men Going Through Chemo
Do A General Sweep Of The Area
The first thing youll need to dois to take a general survey of the area you want to scan with your EMFradiation meter. Start with one room and work your way through the house,office, or whichever other space youre surveying.
Its important to have a pen anda notebook close at hand to record the EMF readings. To begin, flip your EMFmeter to the field marked magnetic field. This is a great starting pointsince magnetic fields are usually generated by nearly every electronic deviceyoull have in your space. Youll be surprised by the amount of radiation yourPC emits.
Next, you want to hold out theEMF meter in front of you and slowly walk forward while moving it back andforth.
What Units Are Used For Measuring Radioactivity
Radioactivity or the strength of radioactive source is measured in units of becquerel .
1 Bq = 1 event of radiation emission or disintegration per second.
One becquerel is an extremely small amount of radioactivity. Commonly used multiples of the Bq unit are kBq , MBq , and GBq .
1 kBq = 1000 Bq, 1 MBq = 1000 kBq, 1 GBq = 1000 MBq.
An old and still popular unit of measuring radioactivity is the curie .
1 Ci = 37 GBq = 37000 MBq.
One curie is a large amount of radioactivity. Commonly used subunits are mCi , ÂµCi , nCi , and pCi .
1 Ci = 1000 mCi 1 mCi = 1000 ÂµCi 1 ÂµCi = 1000 nCi 1 nCi = 1000 pCi.
Another useful conversion formula is:
1 Bq = 27 pCi.
Becquerel or Curie is a measure of the rate of radiation emission from a source.
Don’t Miss: Blood Tests For Liver Cancer