The sand that comes from the Sahara is radioactive (and the nuclear tests have to do with it): what do you risk running?

A team of scientists collected 110 samples of Saharan deposits in various European countries after the exceptional sand storm of March 2022. The researchers detected radioactive isotopes attributable to the American and Soviet nuclear tests of the 60s, explaining what are the effects on the our health

Trints of orange, cars covered by a thin layer of dust, fear for health and debates on nuclear contamination: The Saharan sand transport event that affected Western Europe in March 2022 did not go unnoticed. After some time, a team of researchers from Laboratoire des sciences du climat et de l’ervironnementled by Yangjunjie Xu-Yanghas published a study on Science Advances which lights on an aspect as fascinating as it is controversial: The presence of radioactive isotopes in the particles of the Sahara desert.

The origin of the deposits

During the spring of 2022, strong winds raised enormous quantities of sand from the Sahara, in particular from southern algeria. Over a few days, the dust crossed the Mediterranean, reaching countries like Spain, France, Germany, Belgium, Luxembourg and Austria. With the intention of investigating the composition and possible radioactivity of the sand, the researchers have started a participatory collection campaign involving voluntary citizens. There were thus 110 samples, then reduced to 53 “scientifically representative” Based on chemical, granulometric and mineralogical analyzes.

Attention has focused mainly on the area of Reggane (in southern alger), where France ledin the early 1960s, Four atmospheric nuclear tests known as “Series of Reggane”. This region, together with portions of Mali and Libya, It has long been recognized as one of the most dusty areas of the Sahara.

The radioactive signature: USA and main USSR responsible

Contrary to hypotheses spread in the past, the published results show that the radioactive powder arrived in Europe in March 2022 He mainly bears the isotopic “signature” of nuclear tests carried out by the United States and former Soviet Union during the Cold War. To understand this aspect, the researchers measured the relationship between Plutonio-239 and Plutonium-240. These values, in line with the so -called “global relapse” dominated by the Fallout of American and Soviet experiments, they clearly distinguish from those released in the French tests in the Sahara.

In confirmation of this origin, the study also analyzed the relationship between Cesio-137 and Plutonio: the data that emerged coincide with what was already known for large-scale nuclear residues, while if they had been attributable mainly to French devices, The isotopic values ​​would have been different and lower results. In short, the explosions carried out in Reggane remain against the background of this story of contamination, but do not appear the real cause of the radioactive deposits tracked in European champions.

No radioactive risk for human health

Sandstorms from Sahara, especially when they carry particles of very fine dimensions, raise doubts about air quality and on potential damage to the respiratory system. The study, however, reassures: i levels of radioactivity measured in sand deposits do not reach dangerous thresholds for our health. In particular, both Cesio-137 and Plutonium-239/240 are present in quantities so reduced as not to involve risks according to the radiological safety standards in force in the European Union.

To evaluate the impact on the body, it was considered both the possible ingestion of particles (for example, if the dust ended up on agricultural crops) and direct inhalation. In both cases, The values ​​that emerged from the analyzes are widely below the tolerability limits established at the Community level. From a radiological point of view, therefore, the dust is almost harmless to the population.

The importance of supervising dust and air quality

If radionuclides do not represent a danger, it must still be remembered that The arrival of Saharan sand can increase the values ​​of atmospheric particulate. Some studies recall that, in the presence of intense and frequent phenomena, the concentration of suspension powder – although of natural origin – can aggravate respiratory problems of sensitive individuals, such as asthma or those suffering from other chronic pathologies. In addition to irritating eyes and skin, The finest particles (PM10 and PM2.5) manage to penetrate the airways.

An invitation to participated monitoring

The same research, thanks to the collaboration of simple citizens who have picked up and sent champions to the laboratories, shows how Participatory science (or Citizen Science) can accelerate and expand the collection of data that is difficult to find. The direct involvement of the population, in fact, allows you to have a much higher number of samples than it would have been possible with the only means of researchers, ensuring a capillary geographical coverage.

Exploiting quick and capillary communication channels, people can contribute Significantly to collect essential information to evaluate the quality of the air, the chemical composition of deposits and other parameters useful to trace the evolution of extreme weather phenomena.