Questions from the public

CRPA

The Canadian Radiation Protection Association is a non-profit,  professional organization that supports the development and implementation of radiation safety programs in Canada.  For details regarding the nature of our Association and the types of activities we are involved with, please refer to the About Us page on our website.  Should you be interested in a membership, please refer to the Membership page. 

Radiation and Health Care

We can reassure you that you do not need to worry about working with equipment in a laser clinic while being pregnant. The wavelengths from intense pulsed light (IPL) or lasers used in cosmetics industry are typically in the 400-1200 nm range. In this range, the lasers cannot harm the fetus. In general, radiation falls into two categories – ionizing radiation and non-ionizing radiation. Examples of ionizing radiation include X-rays, such as those used in hospitals or dental offices.  X-rays can penetrate the human body – this is exactly why they are used to take pictures of bones or other organs inside the body. In order to shield against this type of radiation, patients will often wear lead vests to protect the parts of their body that are not being imaged, and the staff may stand behind leaded glass to protect themselves from scattered X-rays produced from the machine. Lasers fall into the second category, which is non-ionizing radiation. While X-rays can penetrate the body, the lasers that you are working with cannot. This means that you do not have to wear any extra protective equipment while you are pregnant. The main hazard in working with lasers is the possibility of damaging your eyes or the surface of your skin. It’s sometimes helpful to think of the hazards of working with lasers the same as you would with the hazards of a knife. Unless the laser you are working with is physically capable of cutting through your skin (not just a burn), it will not cause any harm to anything under your skin.

NO – the amount of radiation delivered in a normal x-ray is very low and is unlikely to affect the fetus in any way.  The normal requirement of informing your physician if you know you are pregnant prior to receiving any x-rays is a “best practice” precautionary measure which enables the physician to consider other options for the examination.  If you have received an x-ray while pregnant and are unsure about the nature of the x-ray exam or the amount of radiation you may have been exposed to, consult with your physician.

Most nuclear medicine diagnostic procedures involve the administration of a radiopharmaceutical (a pharmaceutical including a radioactive material) into a vein and imaging of the photon emissions from the radioactive material. This is a routine procedure, which has been around in various forms (e.g. bone scan, detection of cancer, study of heart and brain) for more than 30 years. Radiation doses from such procedures are quite low (in the order of few millisieverts [mSv], which is roughly equivalent to two years’ exposure to natural background radiation) and is not a hazard to the patient or others. Patients are radioactive for up to a few days (depending on the radiopharmaceutical used), which can be measured if they are near any typical radiation detectors.

Radiation Basics

Radiation is essentially energy traveling through a medium such as air, water, or space. Radiation can be divided into two categories.

The first is electromagnetic radiation, which transports energy in the form of waves, such as radio waves or X-rays.

The second is corpuscular radiation (more commonly known as particle radiation), which is composed of real particles as opposed to waves, such as alpha particles, beta particles and neutrons.

Radiation can also be further divided into ionizing and non-ionizing radiation. This distinction depends on the energy of the radiation. Ionizing radiation has enough energy to remove electrons from atoms, creating ions. Non-ionizing radiation does not have enough energy to remove electrons but instead causes the atoms to move or vibrate

For a more in-depth explanation of radiation, refer to the Radiation and Everyday Life page on the CRPA website.

Radiation which comes from natural sources in the environment is known as “background radiation”.  This includes things like radiation emitted from naturally occurring radioactive materials (NORM), such as natural Uranium in the ground and its decay products such as radon, or the Carbon-14 and Potassium-40 in the human body.  It also includes cosmic rays from the sun. The chart  here provides more details on the sources of background radiation.

Radiation with sufficient energy to strip electrons from or “ionize” atoms when interacting with matter, including human tissue, is called “ionizing radiation.” It may be in the form of either waves, such as gamma or x-rays, or particles, such as alpha particles, beta particles and neutrons.

For a more in-depth explanation of ionizing radiation, refer to the Radiation and Everyday Life page on the CRPA website.

Radioactive material is material which contains atoms which will spontaneously “decay” to form other types of atoms by emitting radiation in the form of particles and gamma rays.  

To understand radioactive material, one needs know a little bit about the composition of matter.  Every material is made up of tiny particles called atoms.  At the middle of each atom is a “nucleus” made up of “protons” and “neutrons”.  The number of protons in the nucleus determines the type of “element”.  If the number of protons and neutrons is properly balanced, the atom will be “stable”.  

The oxygen that we breathe is an example of stable atom.  It will normally contain 8 protons and 8 neutrons, and is referred to as “Oxygen-16”, where 16 refers to the total number of protons and neutrons in each nucleus. However, some combinations of protons and neutrons may not be stable and will “decay” by emitting “radiation”, in the form of particles and energy.  For example, the combination of 8 protons and 7 neutrons is another form or “isotope” of oxygen, known as “Oxygen-15”.  It is unstable or “radioactive”.  It emits a positively charge particle known as a “positron” as well as gamma rays.  In doing so, one of the protons in the nucleus is converted to a neutron, so that the newly created nucleus contains 7 protons and 8 neutrons.  Because there is now one fewer proton, the new atom is actually “Nitrogen-15”.  This combination is stable. 

Radioactive isotopes, also known as radioisotopes, exist all around us naturally, and can even be found in elements such as carbon, hydrogen, and cobalt. They can be found in the ground, for example, in the form of Uranium and its decay products such as radon, in equilibrium with all living things in the form of Carbon-14, and directly in the body in the form of Potassium-40.  Radioactive isotopes may also be produced artificially.  For example, Oxygen-15 is often used for medical diagnostic purposes and is specially produced in a device called a “cyclotron”.

When you are using a cell phone, it must emit very low level “radiofrequency” radiation in order to transmit the information from your phone to the nearest relay tower.  This is a form of “non-ionizing” radiation.  We suggest you visit Health Canada’s very comprehensive website that addresses common concerns regarding radiation from cell phones.

There have been many studies on radiation doses from air travel.  Health Canada has a webpage with information on the topic of cosmic radiation and air travel.

Another excellent resource is the bilingual on-line calculator that allows you to calculate the cosmic radiation dose you might expect to receive during a flight, based on departure point, destination, and flight date and time. To toggle between languages, click on the French or UK flag in the lower right corner.

The www.sievert-system.org website is published by the Institut de radioprotection et de sûreté nucléaire (IRSN), the French institute of expertise in radiation protection and nuclear safety. It provides information on cosmic radiations, doses and health effects. From this data, a typical cross-Canada flight from Toronto to Vancouver would result in a personal dose of about 0.03 mSv, which is ten time less than the annual exposure to cosmic radiation for any Canadian, and less than 2% of the Canadian average annual dose from natural sources of background radiation. Air crews who fly all the time typically receive total professional annual doses on the order of a few mSv in addition to their exposure to natural radiation background.  This level of exposure is well below the annual dose limit applicable for Nuclear Energy Works in Canada, which is 50 mSv in any one year and 20 mSv/y, when averaged over a 5 year period.

This is one of the most difficult questions to answer about radiation.  There are three major issues which make it difficult to explain. 

First is the need to have some understanding of how radiation is measured. 

Second is that people’s perception of what is “safe” vs. what is “dangerous” is very subjective and varies enormously from person to person. 

Finally, there is no “fine line” level of radiation exposure below which you are absolutely safe and above which you are guaranteed to incur harm.

The principal health hazard from exposure to ionizing radiation is the possible development of a cancer in the exposed tissue or organ at some point later in life. At low levels of exposure, the risk of this occurring is very low, but the risk increases in proportion to the amount of exposure. Based on epidemiological studies, the increased risk of developing a fatal cancer due to radiation exposure has been estimated to be about 5% per Sv. In Canada, the probability of developing a fatal cancer (from all causes) during a lifetime is about 25%. Therefore, a dose of 100 mSv results in an increased risk of about 0.5%, increasing the probability of developing a fatal cancer from all causes to 25.5%.

Radiation is considered to be a relatively weak carcinogen. For doses below 100 mSv it is more difficult to detect a difference between exposed and unexposed populations because of the high background incidence of cancer. The conservative approach accepted by many international organizations is to assume that the proportional relationship between radiation exposure and risk can be extrapolated down to extremely low doses; this is called the Linear No-Threshold (LNT) assumption.

Health Canada has a very good website which describes what radon is, how it is produced, when it may be of concern, and how to deal with radon in the home. 

Safety

It is true that the limits in Canada are higher than in some other countries, such as the US. However, this does not mean that Canadians are more susceptible to cancer or other effects of radiation.  Guidelines on the limits are provided by Health Canada and can be found in the Guidelines for Canadian Drinking Water Quality.  The limit in Canada is based upon international radiation protection concepts, including data from the International Committee on Radiation Protection and the World Health Organization.  Some countries have chosen to use slightly different data in their calculations, which results in different limits.  For example, US limits are lower than Canada, but Australian limits are higher. 

The Canadian Nuclear Safety Commission (CNSC) document, Standards and Guidelines for Tritium in Drinking Water, explains these differences in more detail.  Canada has chosen to use a reference dose level of 0.1 mSv/year for limiting tritium.  This is 10% of the general radiation dose limit for the public.  It is 20-30 times lower than the total amount of radiation that an individual would receive in a year from all sources of natural background radiation. 

In 2009, the Ontario government considered lowering the tritium limits in that Province. In response to this proposal, the CRPA wrote a position paper demonstrating that there was,  in fact,  no need to reduce the limits.  There were several reasons for this, including the fact that there was no scientific basis for the proposed decrease.  

It is illegal to discharge any tritium directly to groundwater. Any groundwater which does have elevated levels of tritium is not used as a source of drinking water and does not pose a health risk to the public.

There are pros and cons to the various different types of reactor designs.  Getting into the specific differences would require a very technical discussion, but we can assure you that both the CANDU and South Korean reactors are very safe.   It is worth noting that South Korea operates more than one type of reactor, including 4 CANDU systems as well as a number of different Korean designed systems.  

The companies that build reactors are trying to market and sell their product, and will therefore promote aspects of their equipment that they believe will attract potential customers – much like the manufacturer of any other product would.  Regardless, both types of reactors are built to very high standards and must pass rigorous regulatory requirements before they can be put into operation. 

A detailed evaluation of routine radiation emissions from the reactors would also require a very technical discussion, as it depends upon the specific type of radioactive isotope being considered and emission pathway (e.g., water or airborne).  However, all emissions must meet strict regulatory requirements established by the Canadian Nuclear Safety Commission (CNSC), which is the regulatory authority for nuclear substances in Canada.  The CNSC document Tritium Releases and Dose Consequences in Canada in 2006 contains information on tritium releases from reactors.  Section 4.1.2 shows that tritium releases from the nuclear generating stations in Canada are all well below allowable limits. Health Canada operates the Canadian Radiological Monitoring Network, which takes various measurements of radioactivity including tritium in water vapor around nuclear power plants. You can find this information here.

Services

CRPA maintains an online Business Directory of our Corporate members who offer a wide range of services. In this case, we recommend you check under the category “EMF, RF and Wi-Fi”.  If you are unable to find what you are looking, please let us know and we can try and assist you further.

There is a list of our Corporate members and the services they offer in the Business Directory on the CRPA website.  Many of these companies supply radiation warning signs and placards in addition to other radiation safety related services.  Please visit their websites or contact them directly.  In addition, there are many other general safety supply companies in Canada which can supply bilingual radiation warning signs.  These include, but are certainly not limited to:

Employment, EDUCATION AND Training

There are no universally required education or experience qualifications for working in the field of radiation protection in Canada.  Each employer will set their own requirements, depending upon the nature of the work expected.  In general, potential employers tend to look for education and experience directly related to the scope of their radiation protection program (e.g., a Radiation Technology Nuclear Medicine degree or diploma for work in nuclear medicine, a Medical Physics degree for work in a cancer treatment centre or diagnostic x-ray department, or a Health Physics degree when working in university labs).  

Anyone working in the field of radiation protection in Canada will require specific knowledge of applicable Canadian regulations, such as those of the Canadian Nuclear Safety Commission (CNSC) and/or Health Canada’s Safety Codes. However, there are certain types of jobs within the general field of radiation protection which may require additional qualifications.  For example, to work as a Radiation Safety Officer (RSO) in certain types of facilities, such as nuclear power plants or radiation therapy treatment centers, you may also be required to be certified by the Canadian Nuclear Safety Commission (CNSC).   For more information, please contact the CNSC directly. 

There is a list of CRPA Corporate members in the CRPA Business Directory, many of which offer RSO training courses which include an overview of applicable Canadian regulations.  Please visit their websites or contact them directly for detailed information regarding the courses that they offer. Successful completion of an RSO training course is generally helpful when looking for work in the field of radiation protection in Canada. 

CRPA members who are working as an RSO in Canada are eligible for professional registration as an RSO with the Association.  This includes a formal, written exam process.  Qualified persons may apply to take the exam, which is scheduled during the CRPA Annual Conference (usually in May or June) and may also be scheduled in the Fall in select cities in Canada. More information can be found on the the Professional Designation page of the CRPA website.

Your CNSC licences require that staff working with radiation devices or nuclear substances receive radiation safety training.  In general terms, this includes:

1.   Your Radiation Safety Officer (RSO) should have some type of formal RSO training.

2.   All “authorized users” (i.e., anyone who will be working directly with the gauges or handling the radioactive sources) must take a radiation safety training course. This course may either be “in-house”, or from an external radiation safety consultant.  It must include topics such as basic radiation safety precautions, CNSC regulations and storage and security requirements. It also must address the radiation safety related policies and procedures specific to your company’s operations.

3.   Any support or auxiliary staff who do not work directly with the gauges or sources, but who may be required to work in the immediate vicinity or are otherwise peripherally involved, should receive basic radiation safety “awareness training”.  This is typically at a much lower level than the training required for authorized users.

4.   Any person who prepares, consigns or receives packages containing nuclear substances will require a Transportation of Dangerous Goods (TDG) training certificate which specifically covers Class 7 (radioactive) material.  Again, this training may be provided in-house or through one of the many commercial TDG training consultants.

The general CNSC expectation is that refresher training on these topics be provided every few years.  Servicing of fixed gauges or other radiation devices requires additional training, but servicing requires a separate CNSC licence.  It would not be permitted under your current licences. CNSC document REGDOC 2.2.2, Personnel Training, contains guidelines for developing in-house training programs for workers.

There is a list of Corporate members in the in the Business Directory on the CRPA website. Many of these companies offer these sorts of training courses.  Please visit their websites or contact them directly for detailed information regarding the courses  they offer.

In Canada, by law, anyone performing industrial radiography or operating an exposure device must hold a valid Canadian Nuclear Safety Commission (CNSC) Exposure Device Operator (EDO) certification. This link contains information on the requirements for certification, timelines, costs and copies of the application form and guide. An individual must be certified through the CNSC, regardless of whether or not he/she is certified as an EDO in another country. However, the CNSC will assess each EDO application on a case-by-case basis and may consider alternative types of education, training and experience if they are clearly equivalent to those specified in the application guide.  When applying for EDO certification in Canada, we recommend you included a letter from your current employer and/or the training institution you attended, outlining the training you’ve received and your related work experience, including the types of equipment you are qualified to operate.

Both exams would be suitable for a Radiation Safety Officer.  There is a great deal of common ground between the exams and studying for one will definitely help prepare for the other.  The exams are also similar in content and level of difficulty but the focus tends to be slightly different, with more general content relevant to a broader range of RP applications in the CRPA(R) exam and more emphasis on the nuclear power industry in the NRRPT exam. Assuming you want to choose, or at least decide which to pursue first, here are some things to consider:

CRPA(R) Exam

The Canadian Radiation Protection Association is a national association dedicated to promoting and advancing radiation safety in Canada and has been administering a Registration exam since 2005. Candidates who have successfully completed the process to become a Registered Radiation Safety Professional are given the designation CRPA(R). The exam is based on a competency profile approved by the CRPA, which addresses: radiation safety program administration, the Nuclear Safety and Control Act and RP Regulations, licences, working rules, record keeping, employee qualifications, inspections audits and investigations, exposure and dose control, instrumentation and equipment, inventory management (including transportation), personnel dosimetry, contamination control and emergency procedures. There are over 70 members who have successfully completed the exam.  The exam is scheduled during the CRPA annual conference (usually in May or June) and may also be scheduled in the Fall in select cities in Canada.  All information on becoming an RRSP can be found on the Professional Designation page of the CRPA website.

NRRPT Exam

The National Registry of Radiation Protection Technologists (NRRPT) is an American organization founded in 1976 for the express purpose of advancing the competency of Radiation Protection Technologists. The exam is designed to be relevant to a broad range of fields.  Both the current Board and the Exam Panel include members from many sectors including: nuclear power, national labs (DOE), decommissioning, medical, university, environmental contractors and others. To date, over 5000 people have successfully completed the exam and become “Registrants” of the NRRPT.  While the focus is on RP Techs, the exam has been written by people from many other fields, such as Health Physicists, ALARA managers and RSO’s. The exam is designed to test competency in applied radiation protection, detection and measurement, and fundamentals. The standard for qualification is a competent technologist with five years of experience (and training) who has studied for the exam. 

A Canadian version of the exam has been offered since 2006. It was designed with assistance from Ontario Power Generation and Bruce Power, in order to provide an objective third party standard for their personnel and for contract RP staff brought in for maintenance.   While it was felt that the NRRPT exam was an appropriate standard, much of the content related to US standards and regulations that were not relevant in Canada. Over 50 Registrants have successfully completed the Canadian version of the exam.

Information on the NRRPT exam can be found at www.nrrpt.org

It appears that what you need is a good, high level overview of the basic concepts of radiation and radiation safety.  We suggest you start by reviewing the information on the Radiation and Everyday Life page on the CRPA website. Another good introductory reference can be found on the Introduction to Radiation page of  the Canadian Nuclear Safety Commission (CNSC) website.  

The CNSC website also has an Educational Resources section for school teachers, which may be of interest. Health Canada also maintains an excellent introductory overview on radiation, which includes links to more detailed information on special topics such as radon and ultraviolet radiation.

Miscellaneous

There is no direct Canadian equivalent to NCRP Report No. 147. While you may find the dose limits and other requirements that are applicable in Canada in the Health Canada Safety Codes, or in the appropriate provincial legislation, there is no Canadian document that lays out the methodology of calculating x-ray shielding in the detail that you find in NCRP 147.  In fact, many Canadian documents, such as the Health Canada Safety Codes themselves, simply have references to NCRP 147 or its precursor, NCRP 49. This is the case for many of the NCRP documents. For example NCRP 151, which describes shielding design for megavoltage radiotherapy facilities, is commonly used in Canada, although Canadian dose design targets must be substituted wherever American targets are referenced in the report.