4.4 Radiation
Radiation is any energy emitted from a source, including heat, light, X-rays, microwaves and other waves, and particles. Radiation is categorized into two forms: ionizing and non-ionizing. Ionizing radiation is radiation with enough strength to remove electrons from a molecule as it passes through. The electron loss causes the molecule to become positively charged (called an ion). Examples of ionizing radiation include X-rays, gamma rays, alpha particles, and neutrons. Non-ionizing radiation is unable to ionize molecules but may have other effects, and includes microwaves and radio waves as well as ultraviolet, visible, and infrared light.
Ionizing radiation can occur naturally at low levels from a variety of sources but is uncommon in workplaces. It is most often found in medical, nuclear, and research facilities. When ionizing radiation is present in a workplace, it poses a significant safety hazard. Both short exposures to high levels of radiation and long-term exposure to lower levels have serious health consequences. It is estimated that people are exposed to approximately 0.0125 rem (a standard measure of radiation) of naturally occurring radiation per year. Short-term exposure of 1000 rem will lead to death within a few days. An exposure as low as 10 rem will lead to significant increase in the risk of cancer later in life.
Long-term, lower-level exposure is also a concern as it, too, can lead to increased risk of cancer. The recommended annual exposure for the general public is 0.1 rem. Nevertheless, the ACGIH recommends an annual limit for workers exposed to ionizing radiation to be 2 rem, a figure much higher than public health limits. Controls for ionizing radiation are quite expensive and technical, requiring significant engineering controls. Specialized training is also required, and exposure to ionizing radiation should never be taken lightly.
Warning Sign of Ionizing Radiation
Story: The Elliot Lake strike and the origins of OHS
Comprehensive injury-prevention legislation was only enacted in the late 20th century. One of the catalyzing events was an April 1974 wildcat strike by 1000 uranium miners from Elliot Lake, Ontario, that lasted three weeks. A wildcat strike is an unsanctioned, spontaneous strike by workers. The workers struck over high levels of radiation exposure, and Elliot Lake was one of Canada’s first health- and safety-related walkouts.
Officials from the United Steelworkers of America (USWA), the union representing the workers, had just returned from a uranium safety symposium in France, where they became aware of a study by the Ontario Ministry of Health that showed Elliot Lake miners were three times more likely to die of lung cancer than the rest of the population. The culprit was radiation caused by the release of radioactive radon gas during uranium mining.
The news hit the workers like a bombshell. They did not even know the government was studying them. The workers walked out immediately after the union meeting where the study was revealed. For 10 days, the employer refused to even talk to the workers about the issue, and only agreed to negotiate around safety issues after the strikers refused to return to work.
The workers were particularly angry that both the employer and the government had long known the workers were being exposed to dangerous radon gas but had said and done nothing. As striker Ed Vance put it: “They deliberately kept us ignorant. There is no other way to describe it. Government has a responsibility and in this case they failed to keep the workers advised. They failed to warn the workers of their work environment. And, they were part of that conspiracy.”[1]
The efforts of the Elliot Lake workers eventually resulted in changes to OHS rules. As for the employers, “[the mining companies] were brought in kicking and screaming” to protecting workers, says former miner and President of USWA, Leo Gerard.[2] Elliot Lake revealed how employers’ economic interests combined with the state’s role in maintaining production (in this case, by supporting employers’ interests) can lead to the injury or death of workers.
The Elliot Lake strike, and other direct action taken by workers in defence of their health in the early 1970s, forced governments to do more to protect workers’ health. Within a few years, Ontario’s first Occupational Health and Safety Act was passed and more stringent controls placed upon radiation exposure and other hazards. Other jurisdictions soon followed suit (Saskatchewan actually passed Canada’s first OHS act in 1972). The disturbing question that lingers is whether any of these legislative changes would have come about if the group of miners hadn’t decided they were no longer prepared to die because of their job.
Non-ionizing radiation, in comparison, has less dire health effects, but should not be ignored. Longer-wave non-ionizing radiation (such as microwaves) can cause deep tissue damage, cataracts and other eye issues, and skin rashes as well as interfere with the operation of pacemakers. Infrared radiation can lead to corneal and retinal burns and other eye injuries.
The most common non-ionizing radiation exposure is ultraviolet light (UV). UV radiation damages our skin, leading to burns and permanent skin darkening as well as heightened risk of skin cancer. It also damages our eyes and can cause pain and swelling in the eye and blurred vision, a condition variously called snowblindness, welder’s flash, or flash burn. The sun is the most common source of UV radiation, but UV radiation can also be produced by welding equipment, black light lamps, mercury lamps, counterfeit currency detectors, fluorescent tubes, and nail-curing lamps.
Controls for non-ionizing radiation should include replacing radiating equipment, proper maintenance to prevent fugitive radiation (such as with microwave ovens), separating workers from the radiation source, reducing exposure time to low levels, and using UV-blocking PPE (e.g., hats, clothing, sunscreen).
Are cell phones a cancer risk?
Cell phones are ubiquitous in workplaces, in particular for white-collar occupations. There is an ongoing debate about whether cell-phone use increases a person’s risk of cancer. The main concern is that cell phones emit low-energy radio frequency radiation. It is known that low-energy radiation (such as microwaves) can cause molecules to heat up (which is how microwave ovens work). When a cell phone is used at someone’s ear, the radiation is quite strong near the brain, raising fears of possible risk of brain cancer.
To date, the risk posed by cell phones remains unclear. A number of large-scale studies have failed to find an overall link between cell phone use and cancer.[3] These results have led some organizations, such as the US National Cancer Institute, supported by most governmental agencies, to downplay the risk.[4] However, a number of studies have found possible links between heavy users of cell phones and increased cancer, as well as higher sensitivity to low-energy radiation among children.[5] The International Agency for Research on Cancer (IARC), classifies cell phone radiation as “possibly carcinogenic to humans” (class 2B). Class 2B classification means the IARC feels there is “limited evidence of carcinogenicity in humans and less than sufficient evidence of carcinogenicity in experimental animals.”[6] In short, the IARC feels there is some evidence of a cancer risk but not enough to reach a definitive conclusion.
In contrast, in spring 2015, a group of 195 scientists from 39 countries released a joint letter to the United Nations declaring their position that electromagnetic field (EMF) radiation (of which cell phones are one source) poses a serious health risk to humans, including “increased cancer risk, cellular stress, increase in harmful free radicals, genetic damages, structural and functional changes of the reproductive system, learning and memory deficits, neurological disorders, and negative impacts on general well-being in humans.”[7]
The lack of clarity around the risk of cell phones points to the need for continued research to determine the effects of low-energy radiation. It also suggests a need for increased efforts to decrease the amounts of non-ionizing radiation emitted by cell phones and other devices, even before final conclusions have been drawn.
The current uncertainty over the hazard posed by cell phones (and other EMF sources such as video display terminals and WiFi) is an example of how technology moves much faster than our knowledge of its effects. It can be difficult to gather sufficient evidence to make a clear case (one way or another) in a short period of time, especially when dealing with diseases like cancer, which can have a latency period of decades.
Health agencies tend to be conservative in their recommendations regarding health risks. In the period between introduction of the technology and a clear scientific outcome, workers can be left without adequate protection. Indeed, workers are often the first to exhibit health-related effects of new hazards because they are often the most intensively exposed. The case of cell phones highlights the importance of considering the precautionary principle when adopting new technology.
Cell phones are ubiquitous in workplaces, in particular for white-collar occupations. There is an ongoing debate about whether cell-phone use increases a person’s risk of cancer. The main concern is that cell phones emit low-energy radio frequency radiation. It is known that low-energy radiation (such as microwaves) can cause molecules to heat up (which is how microwave ovens work). When a cell phone is used at someone’s ear, the radiation is quite strong near the brain, raising fears of possible risk of brain cancer.
To date, the risk posed by cell phones remains unclear. A number of large-scale studies have failed to find an overall link between cell phone use and cancer.[8] These results have led some organizations, such as the US National Cancer Institute, supported by most governmental agencies, to downplay the risk.[9] However, a number of studies have found possible links between heavy users of cell phones and increased cancer, as well as higher sensitivity to low-energy radiation among children.[10] The International Agency for Research on Cancer (IARC), classifies cell phone radiation as “possibly carcinogenic to humans” (class 2B). Class 2B classification means the IARC feels there is “limited evidence of carcinogenicity in humans and less than sufficient evidence of carcinogenicity in experimental animals.”[11] In short, the IARC feels there is some evidence of a cancer risk but not enough to reach a definitive conclusion.
In contrast, in spring 2015, a group of 195 scientists from 39 countries released a joint letter to the United Nations declaring their position that electromagnetic field (EMF) radiation (of which cell phones are one source) poses a serious health risk to humans, including “increased cancer risk, cellular stress, increase in harmful free radicals, genetic damages, structural and functional changes of the reproductive system, learning and memory deficits, neurological disorders, and negative impacts on general well-being in humans.”[12]
The lack of clarity around the risk of cell phones points to the need for continued research to determine the effects of low-energy radiation. It also suggests a need for increased efforts to decrease the amounts of non-ionizing radiation emitted by cell phones and other devices, even before final conclusions have been drawn.
The current uncertainty over the hazard posed by cell phones (and other EMF sources such as video display terminals and WiFi) is an example of how technology moves much faster than our knowledge of its effects. It can be difficult to gather sufficient evidence to make a clear case (one way or another) in a short period of time, especially when dealing with diseases like cancer, which can have a latency period of decades.
Health agencies tend to be conservative in their recommendations regarding health risks. In the period between introduction of the technology and a clear scientific outcome, workers can be left without adequate protection. Indeed, workers are often the first to exhibit health-related effects of new hazards because they are often the most intensively exposed. The case of cell phones highlights the importance of considering the precautionary principle when adopting new technology.
- Quoted in Storey, R. (2005). Activism and the making of occupational health and safety law in Ontario, 1960s–1980. Policy and Practice in Health and Safety, 3(1), 48. ↵
- Quoted in Lopez-Pacheco, A. (2014). The strike that saved lives. CIM Magazine (June/July), 34. ↵
- Frei, P., Poulsen, A. H., Johansen, C., Olsen, J. H., Steding-Jessen, M., & Schüz, J. (2011). Use of mobile phones and risk of brain tumours: Update of Danish cohort study. British Medical Journal, 343:d6387, 1–9; Cardis, E., Richardson, L., Deltour, I., et al. (2007). The INTERPHONE study: Design, epidemiological methods, and description of the study population. European Journal of Epidemiology, 22(9), 647–664. ↵
- National Cancer Institute. (2013). Cell phones and cancer risk. http://www.cancer.gov/about-cancer/causes-prevention/risk/radiation/cell-phones-fact-sheet ↵
- Coureau, G., Bouvier, G., Lebailly, P., et al. (2014). Mobile phone use and brain tumours in the CERENAT case-control study. Occupational & Environmental Medicine, 71(7), 514–522. doi: 10.1136/oemed-2013-101754. Morgan, L. L., Kesari, S., & Davis, D. (2014). Why children absorb more microwave radiation than adults: The consequences. Journal of Microscopy and Ultrastructure, 2(4), 197–204. ↵
- IARC. (2015). “Preamble.” In IARC Monographs on the Evaluation of Carcinogenic Risks to Humans. Lyon, France: IARC, p. 23. ↵
- EMFScientist.org. (2015). International Appeal: Scientists Call for Protection from Non-ionizing Electromagnetic Field Exposure, p. 1. https://emfscientist.org/index.php/emf-scientist-appeal ↵
- Frei, P., Poulsen, A. H., Johansen, C., Olsen, J. H., Steding-Jessen, M., & Schüz, J. (2011). Use of mobile phones and risk of brain tumours: Update of Danish cohort study. British Medical Journal, 343:d6387, 1–9; Cardis, E., Richardson, L., Deltour, I., et al. (2007). The INTERPHONE study: Design, epidemiological methods, and description of the study population. European Journal of Epidemiology, 22(9), 647–664. ↵
- National Cancer Institute. (2013). Cell phones and cancer risk. http://www.cancer.gov/about-cancer/causes-prevention/risk/radiation/cell-phones-fact-sheet ↵
- Coureau, G., Bouvier, G., Lebailly, P., et al. (2014). Mobile phone use and brain tumours in the CERENAT case-control study. Occupational & Environmental Medicine, 71(7), 514–522. doi: 10.1136/oemed-2013-101754. Morgan, L. L., Kesari, S., & Davis, D. (2014). Why children absorb more microwave radiation than adults: The consequences. Journal of Microscopy and Ultrastructure, 2(4), 197–204. ↵
- IARC. (2015). “Preamble.” In IARC Monographs on the Evaluation of Carcinogenic Risks to Humans. Lyon, France: IARC, p. 23. ↵
- EMFScientist.org. (2015). International Appeal: Scientists Call for Protection from Non-ionizing Electromagnetic Field Exposure, p. 1. https://emfscientist.org/index.php/emf-scientist-appeal ↵
Energy emitted from a source, including heat, light, x-rays, microwaves, and other waves and particles.
Radiation with enough strength to remove electrons from a molecule as it passes through, such as x-rays, gamma rays, alpha particles, and neutrons.
Radiation without enough strength to remove electrons from a molecule as it passes through but which may cause other effects, and includes microwaves, radio waves and ultraviolet, visible, and infrared light.
A standard measure of radiation.
