Radiation: The Good, the Bad, and the Ugly
“The Atomic Age was born in secrecy, and for two decades after Hiroshima, the high priests of the cult of the atom concealed vital information about the risks to human health posed by radiation.” - Dr. Alice Stewart, an audacious and insightful medical researcher, was one of the first experts to alert the world to the dangers of low-level radiation
“Millions of Americans every year depend upon medical imaging exams to diagnose disease and detect injury, and thousands more rely on radiation therapy to treat and cure their cancers.” - Charles W. Pickering
“The current lack of a national standard for operators of medical imaging and radiation therapy equipment poses a hazard to American patients and jeopardizes quality health care.” - Charles W. Pickering
“'Not to worry,' their bosses told them. 'If you swallow any radium, it'll make your cheeks rosy.'' - from "Radium Girls" by Martha Irvine (At the US Radium Corporation factory in Orange, New Jersey around 1917. The women at Radium Dial sometimes painted their teeth and faces and then turned off the lights for a laugh.)
All life is dependent on small doses of electromagnetic radiation. Plants live by converting this energy through photosynthesis, sustaining themselves and in turn providing food for many of the earth’s animals. We also are surrounded by and depend on radiation-emitting devices, including cell phones, radios, medical x-rays, and the electricity that powers our homes. Radiation-emitting devices have many benefits, but we are still learning about some of their health effects.
The electromagnetic spectrum is roughly divided into ionizing and nonionizing radiation. The distinction depends on the amount of energy carried by the radiation, which is directly related to the frequency of vibration of the electric and magnetic fields. When the frequency (and hence energy) is high enough, the radiation can separate electrons from atoms, ionizing the material it passes through. For biological material, this energy can damage cellular DNA and disrupt function. Nonionizing radiation includes ultraviolet, visible, and infrared light, microwaves, radio and TV waves, and power transmission. Ionizing radiation includes high-energy radiation such as cosmic rays, x-rays, or gamma rays generated by nuclear decay. Ionizing radiation also includes several types of sub-atomic particles such as beta radiation (high-energy electrons) and alpha radiation (helium ions). Medical x- rays are an example of a common beneficial exposure to ionizing radiation.
Assessing the human health and ecological effects of both ionizing and nonionizing radiation is complex. While we depend on the sun, we are also familiar with the hazards of solar radiation that can result in sunburn, cataracts, and skin cancer. Microwave radiation, used by cell phones, is also a potential concern as it warms the skin or internal organs. Excessive use of a cell phone on the ear may increase the rate of brain cancers. There is also controversy around the potential hazards of exposure to low-frequency energy such as AC power lines. The challenge, as always, is to limit exposure.
The effects of high-dose ionizing radiation are well documented. We also know a great deal about energy emitted and how to reduce exposure. An important distinction is whether exposure to a radioactive material is external, or through ingestion of a radioactive particle. Ingestion of a radioactive particle results in nearby cellular exposure and a greater likelihood of cellular damage resulting in cancer. For example, iodine-131 is taken up by the thyroid and can cause thyroid cancer. The young are particularly vulnerable.
The challenge that our modern society faces is to exploit the properties of ionizing and nonionizing radiation while putting in place appropriate safeguards that protect human and environmental health. We must also recognize that children are more vulnerable to radiation exposure than adults, be it solar radiation, microwaves, or iodine-131. We have an ethical responsibility to ensure that our children can reach and maintain their full potential, free of unnecessary radiation exposure.