From “atom” to “decay”: new app calculates radiation dose and provides knowledge about radiation and radioactivity


Whether it is the contamination of wild mushrooms with radioactive caesium from Chernobyl, the landfilling of waste from decommissioning of nuclear power plants, or radon in homes – the topics of radioactivity and radiation attract many people’s attention. To give interested people the opportunity to learn more about these phenomena, a team of young experts from Gesellschaft für Anlagen- und Reaktorsicherheit – the GRS AppLab – developed the app “Curious Marie”. The app can be used to calculate a prognosis of personal radiation exposure on the basis of individual data. In addition, “Curious Marie” offers background information in the form of a quiz, animation video and FAQ.

Place of residence, X-rays, air travel, cigarettes - with four details to the individual radiation dose

In their lives, people are constantly exposed to ionising radiation. Whether cosmic radiation, medical applications such as X-rays or the use of radioactive substances in research and industry – the average radiation exposure of an individual in Germany is around 4 millisieverts per year from a variety of natural and man-made radiation sources. The level in the individual case, however, depends strongly on the behaviour of the individual person. “If you want to know what dose you actually receive, you have to look at the factors that make a significant contribution,” explains Holger Seher, project manager at the GRS AppLab.

In the app, users can therefore enter individual data in four categories that are decisive for their personal radiation exposure. This includes, for example, entering the place of residence. This is decisive for the dose from natural background radiation. Furthermore, certain medical examinations, air travel and, if applicable, daily tobacco consumption can be entered. On the basis of these data, “Curious Marie” then calculates a prognosis of the individual radiation exposure for the current calendar year. For each of the categories, the app also provides background information in the form of questions and answers. The users will not only be provided with basic information about the respective radiation sources, but also learn on which assumptions and data the prognosis calculations are based.

Quiz and learning videos to better understand and assess the effects of radiation doses

A quiz was designed to give interested lay people and learners an understanding of the physical basics behind phenomena such as radiation and radioactivity. In three levels, the users can play their way through from nuclear physics to radiation protection and, as Seher hopes, develop their own understanding of the topic: "We have all experienced in our private environment that many people feel insecure about radiation because they lack the ability to properly assess things based on their own knowledge. If, for example, you know what health damage can occur at what dose, you can also judge how important it can be to protect yourself from radon or whether you want to visit the exclusion zone in Chernobyl.” In addition to the quiz, 13 short animated videos in “Curious Marie” provide an introduction to basic terms and phenomena such as “Becquerel”, "Radioactivity" or "Nuclear fission and fusion“.

The “Curious Marie” app is now available free of charge for iOS and Android. All personal data is stored exclusively on the users' end devices. The app does not access other user data or transfer such data to third parties.

More Information

>> Curious Marie on iStore (Apple)

>> Curious Marie on Google Play (Android)

About GRS

Gesellschaft für Anlagen- und Reaktorsicherheit (GRS) gGmbH is a non-profit research and expert organisation with a majority stake held by public sector entities. Since its foundation in 1977, it has supported the federal authorities as an expert and has been working on publicly funded research projects. The most important international client is the European Commission.

Find out more about GRS at


Sven Dokter
Press Officer and Head of Communication Department
Phone: 0221 - 2068 654
sven.dokter [at]