Ionising radiation — naturally occurring and man-made. What are the hidden dangers?

There are different types of ionising radiation (alpha particles, beta particles, gamma rays and X-rays). These various types of radiation describe the different speeds and different weights of packets of energy, which have enough force to remove electrons from atoms. Ionising radiation can come from natural sources such as radon, for example, or it can be man-made, as in the case of X-rays and so on.

We humans tend to be exposed to natural radiation, rather than man-made, as a result of our exposure to cosmic radiation, and to the sun. The earth’s crust also emanates radioactive particles, radon being the major source. Man-made sources tend to be used in medical and research institutions; nuclear reactors; uranium mills and fuel preparation plants, and; nuclear weapons production. Exposure to these may be unrecognised, since radioactive by-products can be released in limited quantities into the environment. Some consumer products, such as luminous signs and smoke detectors also contain radioactive particles. Other than this, there can be huge, unintended release of radiation into the environment, such as occurred as a result of the nuclear accidents at Chernobyl and Fukushima.

So what are the implications for our health? If the body is exposed to ionising radiation, packets of energy are deposited in the body’s tissues. This energy can cause cell death, or, it can cause mutations in the DNA within the nucleus of the cell. These damaged cells can reproduce, and, in some cases, tissue can undergo malignant change.

Exposure can be chronic, which means low doses over long periods of time. The long-term effects include development of benign and malignant tumours and genetic aberrations. There can be a delay of several years after exposure before the health effects are noticed. Acute exposure, on the other hand, is short-term high-dose, and can cause both immediate and delayed effects. Examples of acute exposure are as a result of X-rays and radiotherapy, or as a consequence of a nuclear accident.

All ionising radiation probably carries a health risk, and so it is prudent to moderate exposure. Having said this, any human body which has an intact immune system is equipped to deal with some ionising radiation, since our species has survived for millennia on the earth, against a background of chronic natural exposure. However, if we examine more closely the organs affected significantly by acute exposure as a result of a nuclear accident for example, the bone marrow, thyroid gland, and lens of the eye are significantly affected, since they are particularly sensitive to radiation.

After radiotherapy (or other acute exposure), the number of white blood cells is markedly decreased, and this is thought to be the result of bone marrow irradiation. Immunity is obviously reduced, at least temporarily, since the lymphocytes (white blood cells) are made in the bone marrow. For anyone who has experienced acute exposure, prompt removal of ionising radiation from the bone marrow will improve the immune status considerably.

Radon gas is the second leading cause of lung cancer in the US. It is a radioactive gas released by some of the elements in the earth’s crust. It is invisible, odourless and tasteless and can seep into buildings from the rocks and soil beneath. Levels tend to build up in buildings that are well-sealed and free from ventilation. It is well-recognised that granite (now a popular material for kitchen work-tops) and marble can emit radon, as can sandstone. Stone cutters are potentially more at risk than the general population, as are some populations who live in particular geographical locations, for example Cornwall in the UK.

The food chain can be a further source of radiation. If fish or animals have become contaminated, any radioactivity is passed along the food chain.

Air travel causes increased exposure to cosmic and solar rays due to the reduced atmospheric shielding at elevated height. But the exposure is often very low unless you’re a frequent air traveller, or work as part of an air cabin crew. Inter-continental flights carry more of a risk since the flight altitude is greater.

FCT aims to detect and remove ionising radiation from the body and would recommend those with higher than average exposure to seek its removal. At-risk groups include: those working with radon-emitting materials; frequent fliers; those living in areas of increased background radiation, and; those prone to ill-health.