A two-step concept to derive a consistent set of intervention levels for radiation emergency planning and to translate international recommendations into practical guidance.

A two-step concept is proposed in order to derive a consistent set of intervention levels for early (sheltering, evacuation) and late (relocation/resettlement, returning) protective actions that have to be considered in radiation emergency planning. In the first step, the dose ratios of the projected effective doses have to be calculated for four defined time periods, which correspond with the integration times for sheltering and relocation. In the second step, it is necessary to adopt an intervention level for one protective action or a more general reference level for a certain time period as, for example, the reference level recommended by the International Commission on Radiological Protection (ICRP) Publication 103 in 2007. The adopted intervention level or reference level and the relationships between the projected effective doses are used to derive a consistent set of intervention levels for early and late protective actions. To illustrate the two-step concept, four sets of intervention levels are exemplarily derived for two accidental releases from nuclear power plants.

Mixtures of Uncaria and Tabebuia extracts are potentially chemopreventive in CBA/Ca mice: a long-term experiment.

A long-term experimental animal model was developed by our research group for the evaluation of potential chemopreventive effects. The inhibitory effects of agents on carcinogen (7,12-dimethylbenz[a]anthracene (DMBA) induced molecular epidemiological biomarkers, in this case the expression of key onco/suppressor genes were investigated. The expression pattern of c-myc, Ha-ras, Bcl-2, K-ras protooncogene and p53 tumour suppressor gene were studied to elucidate early carcinogenic and potential chemopreventive effects. The consumption of so-called Claw of Dragon tea (CoD™ tea) containing the bark of Uncaria guianensis, Cat's Claw (Uncaria sp. U. tomentosa) and Palmer trumpet-tree (Tabebuia sp. T. avellanedae) was able to decrease the DMBA-induced onco/suppressor gene overexpression in a short-term animal experiment. In a following study CBA/Ca mice were treated with 20 mg/kg bw DMBA intraperitoneally (i.p.) and the expression patterns of onco/suppressor genes were examined at several time intervals. According to the examined gene expression patterns in this long-term experiment the chemopreventive effect of CoD™ tea consumption could be confirmed.