WHO reduces recommended radon limits
The World Health Organisation (WHO) had previously recommended not exceeding 1.000 becquerels (Bq the unit used to measure radioactive activity) of radon per cubic metre inside homes. However, last week, the WHO released a guide on this subject, in which it sets a new limit of 100 Bq/m3. The Torrelodones study shows that radon in more than half of the homes there is in excess of this amount.
Sainz points out that radon is a colourless, odourless and tasteless gas generated by the decay of uranium-238 (a natural radioactive element present in all rocks and soil in varying degrees). "It is much more abundant in granite areas, such as Torrelodones and other areas in the west of the Iberian Peninsula, such as parts of Galicia, Salamanca and Cceres", explains the expert.
The study also analysed radon levels in Stei, an area in Transylvania, Romania, where there are old uranium mines, and where the incidence of lung cancer has been shown to be 116.82% higher than estimates. Radon levels of up to 2,650 Bq/m3 have been recorded in some homes.
Ventilation and barriers against radon
Radon gas is emitted by the subsoil and seeps into houses to a greater or lesser degree depending upon the permeability of the ground through the pores and cracks in garages and basements. This radioactive element accumulates to a greater extent in single family homes and ground floor flats than in those located higher up in apartment blocks.
In order to address the problem, in addition to regularly checking levels of this gas, the experts suggest ventilating cellars and basements with extractor fans (opening windows alone may not be sufficient, depending on the levels of the gas). The construction of architectural barriers that are impermeable to radon is also recommended, above al
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