Carmen was diagnosed with lung cancer two years ago, when she had just turned 63. She was surprised by the diagnosis, because neither she nor her husband Pepe had ever smoked.
Investigating the possible causes, he found that in the area where he lived, in the Sierra de Guadarrama, there were high concentrations of a gas called radon, colorless, odorless and tasteless. She ordered a measurement from a Laboratory Accredited by the National Accreditation Entity (ENAC) and discovered to her surprise that there was a concentration of 1,200 becquerels per cubic meter (Bq / m3) in her home. This was four times higher than the maximum concentration established by a European Directive published in 2014.
Carmen was even more shocked when she learned that the Government of Spain has not transposed that directive 3 years after the mandatory deadline for it has expired. Quickly, he contacted a specialized company that managed to reduce the radon concentration significantly, to 150 Bq / m3.
A dangerous carcinogenic gas
The little knowledge that exists about this gas on the part of the Spanish population is surprising. As is also surprising the inaction of most public administrations in this country.
Radon gas is a radioactive gas that comes from the decomposition of Radio 226 that is present in all the rocks of the earth’s crust. This gas enters homes through cracks, fissures or poorly sealed joints and can reach dangerous concentrations in homes and workplaces located in hazardous areas.
In Spain, these areas are mainly granitic, since granite contains a lot of Uranium and Radium – from which radon comes. The areas of Spain with the highest risk have been adequately characterized by the Nuclear Safety Council (CSN) in a Map with 12,000 measurements in homes , in which the Galician Radon Laboratory of the University of Santiago de Compostela participated. According to the CSN, which is the national authority on radiological protection, 70% of Galicia, 47% of Extremadura and 36% of Madrid, have a high probability of presenting high concentrations of radon gas.
Radon gas was declared a human carcinogen in 1988 by the International Agency for Research on Cancer and the WHO has established that it is the second risk factor for lung cancer in smokers and the most important among never smokers.
When is it dangerous?
In 2009, a report from the World Health Organization (WHO) was published, in which our group participated, which concluded that ideally it should not exceed 100 Bq / m3 and in no case 300 Bq / m3. This recommendation is based on solid scientific evidence published in the most cited study on radon and lung cancer (British Medical Journal, 2005) that included more than 21,000 participants, observing a linear risk between radon exposure and risk of lung cancer .
At this point, it is also important to underline that there is an important interaction between radon and tobacco use. Specifically, smokers exposed to high concentrations of radon gas multiply the chances of developing this cancer.
Searching for the invisible enemy
In 2014, the International Agency for Research on Cancer indicated in the European Code Against Cancer that the measurement of radon gas in homes should be promoted to reduce the probability of developing lung cancer in the future. The measurement is simple and cheap, and must be done by an Accredited Laboratory.
On the other hand, there is strong scientific evidence obtained in different studies carried out by our group with the collaboration of numerous hospitals on the risk of lung cancer in subjects exposed to radon gas in Spain, both in smokers and never smokers. The last one, published in 2020, included more than 3,700 participants from various Autonomous Communities.
In the same way that radon can be concentrated in homes, it also accumulates in jobs located in risk areas and we have registered up to 7,000 Bq / m3 in workplaces. A study that we carried out in collaboration with ISTAS, of Comisiones Obreras, and which is the largest published in Spain in this area, calculated that 27% of jobs exceeded 300 Bq / m3.
Finally, the importance of mapping risk areas must be emphasized. In Galicia, our Laboratory started the Galician Radon Map in 2001, which has 4,300 measurements in homes and will soon be expanded to 5,000 measurements. Even so, many more measurements are needed throughout Spain to improve the characterization of radon exposure.
Meanwhile, Carmen is treated at the Puerta de Hierro Hospital. She is happy, because she is in good hands. In addition, she has already warned her neighbors in the urbanization so that, before history repeats itself, they try to find out if there may be a high concentration of radon, the invisible enemy, in your house.
Alberto Ruano Raviña, Professor of Preventive Medicine and Public Health, University of Santiago de Compostela
This article was originally published on The Conversation. Read the original.
