Elements that threaten us

Radon has affected human health throughout history although it wasn't until 1988 that it was officially declared a human carcinogen. Radon originates as a part of the natural decay process of uranium and thorium. These elements are ubiquitous in the earth's crust, therefore radon is found in varying concentrations on most of the planet. However, it isn't until radon is concentrated in buildings, or in underground workplaces, that it poses a health risk to humans.

Radon has been found to be the primary cause of lung cancer among non-smokers, while contributing to an increased number of lung cancer victims among smokers and ex-smokers. The World Health Organization (WHO) has calculated that radon causes between three and 16 percent of all lung cancer deaths and is second only to smoking as the leading cause of lung cancer.

So how does exposure occur?

Radon from the soil seeps through cracks in buildings' foundations, floors and walls. In some instances, the building materials can be an important source of indoor radon. If the building is not well ventilated, then the gas will concentrate in the lower floors where it is breathed in by occupants. The gas concentrations can vary significantly from place to place and indoor concentrations are affected by climate and temperature changes. This variability makes testing challenging. Additionally, studies have shown that there is no minimum threshold below which radon levels do not pose a risk to human health. Therefore, any level represents an increased risk of lung cancer.

Radon levels in Ireland are higher than the international average and thus Ireland has extensive experience in developing action plans to deal with the challenge. David Polland, of the Radiological Protection Institute of Ireland, explained that educating stakeholders and governmental agencies on the health risk posed by radon is key to any State's action plan on reducing radon.

The necessary technology exists to reduce radon concentrations in existing homes. However, householders are often reluctant to measure and to spend money on corrective actions. Cost-benefit analysis has shown that prevention strategies are the most cost effective way to reduce radon exposure. Architects and building contractors are key stakeholders and need to be educated on the need to design buildings to prevent accumulation of radon.

For its part, the IAEA has prepared a new Safety Guide - in cooperation with the World Health Organization (WHO) - describing how to develop a national action plan to assess and, if necessary, reduce exposures due to radon (and also gamma radiation) in homes. The Safety Guide includes advice on the provision of information, conducting radon surveys, defining measurement protocols, developing national policies and evaluating effectiveness. Many Member States already have a national plan in place to protect their population from radon and all others are urged to consider establishing such a programme.

Courtesy:  Joe Brazda, IAEA