The Martian surface is constantly exposed to a high dose of cosmic radiation consisting of highly energetic particles and multiple types of ionizing radiation. The dose can increase temporarily by a factor of 50 through the occurrence of highly energetic solar flares. This may affect crop growth in greenhouses on the Martian surface possibly making settlement of humans more complicated. Shielding crops from radiation might be done at the expense of lighting efficiency. However, the most energy-efficient cultivation may be achieved through the use of natural daylight with the addition of LED lights. The goal of our research was to investigate whether Martian radiation, both the constant and the solar flares events, affects plant growth of two crop species, rye and garden cress. The levels of radiation received on the surface of Mars, simulated with an equivalent dose of 60Co γ-photons, had a significant negative effect on the growth of the two crop species. Although germination percentages were not affected by radiation, biomass growth was significantly decreased by 32% for cress and 48% for rye during the first 4 weeks after germination. Part of the biomass differences may be due to differences in temperature between radiation and control treatment, however it cannot explain the whole difference between the treatment and control. Coloring of leaves, necrosis and brown parts, was observed as well. Temporary increases in ionizing radiation dose at different development stages of the plants did not significantly influence the final dry weight of the crops.@en

Dit boek beoogt systematisch inzicht te geven in de gevaren van toepassing van ioniserende straling en de mogelijkheden van de medewerker zelf om die gevaren te beheersen. Het boek is niet alleen gericht op veiligheidsaspecten, maar is ook bruikbaar als studiemateriaal voor HBO-opleidingen en universiteiten om studenten een algemeen inzicht te geven in de toepassing van ioniserende straling. Ten slotte is het mogelijk om het boek te gebruiken voor de opleiding tot toezichthouders op 5A- of 5B-niveau. Ten opzichte van de vorige druk, zijn in deze nieuwe 7e druk in alle hoofdstukken correcties, wijzigingen en aanvullingen aangebracht en is alle nieuwe regelgeving verwerkt.@en

This book provides information on current measures to protect oneself against the risks of ionising radiation. It also explains the legal reasons, the physical basis and the biological necessity for these measures, to motivate compliance with them. In addition, it gives a strategy - the source oriented strategy - that the worker can use to make the right choices for the necessary precautions when there are no rules or regulations to rely on. To make the book as practical as possible, unnecessary theoretical and technical items have been avoided. This third English edition represents the English version of the recent seventh edition of the Dutch book `Praktische Stralingshygiene¿, ISBN 978 90 77423 99 8. It can be used in other European countries, as most radiation protection measures to be taken by workers are the same everywhere, and the only items that can be country-specific (`rules¿ in Chapters 6 and `radioactive waste¿ in Chapter 11) are treated from the perspective of the European Council Directive 96/29/EURATOM. In this edition there are changes in all chapters.@en