What is radiation?
Radiation is often described as energetic particles or waves travelling through a substance or space. There are many different kinds of radiation, both natural and manmade in origin. There are two broad categories of radiation: ionizing and non-ionizing. When people talk about radiation they are usually referring to ionizing radiation, radiation strong enough to knock an electron off of an atom. Examples of this can be found in nature including cosmic radiation from outer space or radioactive materials naturally occurring in the earth. These forms of radiation make up what is known as background radiation. Humans not only get exposed to this type of radiation, we also contribute to ionizing radiation (higher frequency and shorter wavelength) when running common medical diagnostics like x-rays. Non-ionizing radiation on the other hand, does not carry enough energy to completely remove an electron from an atom. There are many examples of non-ionizing radiation (lower frequency and longer wavelength) in our environment, including ultraviolet radiation from the sun, light, heat, microwaves and radio waves.
How is radiation harmful?
Non-ionizing radiation does have its dangers with over exposure. For example spending too much time in the sun will cause our skin to burn.
Discussions around the dangers of radiation exposure often refer to ionizing radiation. This type of radiation causes physical damage to living tissue. When electrons are “knocked” from atoms, the atom becomes excited and attempts to interact with another atom. These interactions can produce free radicals that damage important molecules and cellular DNA, eventually leading to tissue destruction. DNA is the blueprint to make new cells. If it is damaged, the newly produced cells may not function properly and tumor growth can occur. Large doses of exposure at one time, like after nuclear accidents or fallout from weapons, can cause radiation sickness, cataracts, hair loss, sterility, burns, loss of thyroid function and death. Children are more susceptible to radiation because they are growing rapidly, more cell divisions are taking place and there is a higher chance for damage to occur. That is also why x-rays are not performed on women who are pregnant.
Radiation in Medicine
Radiation is used in medicine for many tests, the most common being x-rays, cat-scans, mammograms and nuclear medicine (where radioactive material is injected into the body). The degree of radiation exposure with each test varies greatly. There is no conclusive evidence that having a single radiological test will cause problems, but having repeated tests does increase people’s exposure to above normal levels of background radiation. The benefit of a proper diagnosis has to be weighed against the risk of the radiation exposure.
In conclusion, radiation is all around us. Both ionizing and non-ionizing radiation can cause damage if over-exposed. The most dangerous exposure would be from acute high dose exposure after a major accident such as a nuclear reactor melt down. The most serious problem with long-term exposure to low doses of radiation is the development of cancer.
Check out this free app from iTunes to calculate your exposure: My Radiation
Electromagnetic fields (EMFs) represent a growing environmental influence. All populations are exposed to varying amounts of EMFs. According to the World Health Organization (WHO) the levels will continue to increase with advances in technology. Some current sources include video display units (VDUs) associated with computers, mobile phones and their base stations. The exposure to EMFs is growing exponentially, creating different perspectives and controversy on the health implications.
The health effects of mobile phones are an increasing concern. Numerous studies have investigated the effects of radiofrequency fields on brain electrical activity, cognitive function and sleep. Tissue heating is the principal short-term interaction between radiofrequencies and the human body. To date, research does not suggest consistent evidence of adverse effects although concerns have been raised. Most energy is absorbed by the skin and other superficial tissues; the resulting temperature rise in the brain or organs is understood to be negligible. Long-term research has mainly focused on potential risks with brain tumours. There are some indications of increased risk associated with cumulative hours of cell phone use (reported in a retrospective case-control study on adults, INTERPHONE, coordinated by the International Agency for Research on Cancer). Researchers concluded that biases and errors limit the strength of the study, therefore preventing a causal relationship. The WHO does mention that these many limitations cannot completely rule out negative health implications from cellular phones.
Electromagnetic hypersensitivity is a variety of non-specific symptoms reported by individuals following exposure to EMFs. Dermatological symptoms, including redness, tingling and burning sensations, are the most commonly reported. In addition fatigue, tiredness, dizziness, nausea and heart palpitations have been experienced. Currently, the collection of these symptoms are not a recognized syndrome, much like fibromyalgia, chronic fatigue syndrome and multiple chemical sensitivities were not recognized.
While the increased risk of brain tumours with the rising use of mobile phones is lacking in the data, further research is necessary. The WHO has also recommended exploring the health effects of longer life time exposure (over 15 years) to children and adolescents.
At Nature Medicine, we believe that the cumulative exposure to these fields, not merely cell phones, does play a contributory role to disease, especially when other disease causing factors are present. For example, the presence of mercury fillings in conjunction with EMFs can create a cumulative significant health challenge.
- My Radiation: Free application from iTunes
- World Health Organization: http://www.who.int/peh-emf/en/