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Study: cancer risk is increased by natural radiation
Regional differences in the natural background radiation from the soil and space appear to have an impact on the risk of cancer in children. This is shown by a new study from Switzerland. Accordingly, even small doses of radiation in children can promote cancer.
A study by the University of Bern shows that regional differences in natural background radiation from the ground and in space can influence the risk of cancer in children. As reported by the Swiss National News Agency (SDA), the study provides tangible evidence that even relatively small radiation doses promote cancer in children. Every year, around 200 children and adolescents under the age of 16 get cancer in the Alpine Republic, most often blood cancer (leukemia) with 30 percent of all cases and brain tumors with 20 percent.
Harmful effects have been known for a long time. The causes of this have so far been largely unknown. However, ionizing radiation is a known environmental cause, particularly for these two types of cancer. As the agency explains, ionizing radiation is the type of radiation that comes from radioactive materials, for example. It has been known for decades that high doses are harmful to health. For example, the effects of the atomic bombing in Japan or the consequences of the meltdown in Chernobyl and Fukushima have been reported worldwide. However, the population is also exposed to an omnipresent, natural background radiation from the earth and space.
How does the low, continuously occurring dose affect? As the University of Bern has now announced, it was previously unknown how this low, continuously occurring dose over many years affects the risk of cancer in children. Because these are very low doses and rare diseases, this question had to be investigated using large samples. The team led by Ben Spycher and Claudia Kuehni from the University of Bern found this in the Swiss National Cohort: This includes all children recorded in the 1990 and 2000 censuses, a total of over two million children under the age of 16.
Some children are exposed to increased radiation exposure The researchers combined the data with radiation maps of Switzerland, with which they were able to estimate the dose rate (dose per unit time) of terrestrial and cosmic radiation at the place of residence of the children at the time of the census. With the help of the Swiss Childhood Cancer Registry, the cancers could be identified after this time. As it turned out, about one percent of children in Switzerland are exposed to increased radiation levels of over 200 nanosieverts per hour from rock or the cosmos. Eleven leukemias and eight brain tumors were diagnosed in these children. When asked by the SDA, lead author Spycher stated that children who are exposed to 100 nanosieverts per hour or less would be expected to receive the usual dose in the Midlands, only six cases of leukemia and about four brain tumors. The cancer risk increases by around four percent per millisievert of additional cumulative dose, both for leukemia and for brain tumors. The scientists explained that these values are similar to a recent study from England.
Other components of radiation exposure According to the researchers, regional differences such as life in the country or in the city, a decline in prosperity or the proximity to highways, high-voltage lines or radio and TV transmitters could not explain these risk differences. However, terrestrial and cosmic radiation are only two components of the total radiation exposure of the population. Even greater is the exposure to radon, which arises when natural uranium decays in the ground and can penetrate into buildings via cracks. Above all, this gas increases the risk of lung cancer. Medical diagnostics, such as X-rays, is also an important source of radiation. The burden is an average of 1.2 millisieverts per person per year. This corresponds to the magnitude of the natural background radiation. And even on long flights, passengers and crew are exposed to increased cosmic radiation. (ad)
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