Analysis of mortality in a pooled cohort of Canadian and German uranium processing workers with no mining experience.

PurposeLong-term health risks of occupational exposures to uranium processing were examined to better understand potential differences with uranium underground miners and nuclear reactor workers.MethodsA cohort study of mortality of workers from Port Hope, Canada (1950-1999) and Wismut, Germany (1946-2008) employed in uranium milling, refining, and processing was conducted. Poisson regression was used to evaluate the association between cumulative exposures to radon decay products (RDP) and gamma-rays and causes of death potentially related to uranium processing.ResultsThe pooled cohort included 7431 workers (270,201 person-years of follow-up). Mean RDP exposures were lower than in miners while gamma-ray doses were higher than in reactor workers. Both exposures were highly correlated (weighted rho = 0.81). Radiation risks of lung cancer and cardiovascular diseases (CVD) in males were increased but not statistically significant and compatible with risks estimated for miners and reactor workers, respectively. Higher RDP-associated CVD risks were observed for exposures 5-14 years prior to diagnosis compared to later exposures and among those employed <5 years. Radiation risks of solid cancers excluding lung cancer were increased, but not statistically significant, both for males and females, while all other causes of death were not associated with exposures.ConclusionsIn the largest study of uranium processing workers to systematically examine radiation risks of multiple outcomes from RDP exposures and gamma-rays, estimated radiation risks were compatible with risks reported for uranium miners and nuclear reactor workers. Continued follow-up and pooling with other cohorts of uranium processing workers are necessary for future comparisons with other workers of the nuclear fuel cycle

Genetic modifiers of radon-induced lung cancer risk: a genome-wide interaction study in former uranium miners

PURPOSE: Radon is a risk factor for lung cancer and uranium miners are more exposed than the general population. A genome-wide interaction analysis was carried out to identify genomic loci, genes or gene sets that modify the susceptibility to lung cancer given occupational exposure to the radioactive gas radon. METHODS: Samples from 28 studies provided by the International Lung Cancer Consortium were pooled with samples of former uranium miners collected by the German Federal Office of Radiation Protection. In total, 15,077 cases and 13,522 controls, all of European ancestries, comprising 463 uranium miners were compared. The DNA of all participants was genotyped with the OncoArray. We fitted single-marker and in multi-marker models and performed an exploratory gene-set analysis to detect cumulative enrichment of significance in sets of genes. RESULTS: We discovered a genome-wide significant interaction of the marker rs12440014 within the gene CHRNB4 (OR = 0.26, 95% CI 0.11-0.60, p = 0.0386 corrected for multiple testing). At least suggestive significant interaction of linkage disequilibrium blocks was observed at the chromosomal regions 18q21.23 (p = 1.2 × 10-6), 5q23.2 (p = 2.5 × 10-6), 1q21.3 (p = 3.2 × 10-6), 10p13 (p = 1.3 × 10-5) and 12p12.1 (p = 7.1 × 10-5). Genes belonging to the Gene Ontology term "DNA dealkylation involved in DNA repair" (GO:0006307; p = 0.0139) or the gene family HGNC:476 "microRNAs" (p = 0.0159) were enriched with LD-blockwise significance. CONCLUSION: The well-established association of the genomic region 15q25 to lung cancer might be influenced by exposure to radon among uranium miners. Furthermore, lung cancer susceptibility is related to the functional capability of DNA damage signaling via ubiquitination processes and repair of radiation-induced double-strand breaks by the single-strand annealing mechanism

Discrimination and association processes for faces and non-faces: The effect of rotation

Most current theories of face perception claim that inversion leaves the coding of non-face stimuli largely unaffected, while causing a qualitative change in the coding of faces. Empirical support for this hypothesis mainly stems from recognition studies which typically show a larger inversion decrement for faces than for other stimuli. Several recent studies using experimental paradigms that do not contain a substantial memory component have however yielded contradicting results. This observation suggests that the disproportionate effect of inversion for faces might be related to the presense, or absence, of a memory component in the experimental task. In order to explore this hypothesis we investigated the effect of inversion within a discrimination learning paradigm, which contains a memory component comparable to that included in a recognition paradigm. We compared the effect of rotation on discrimination and association processes for faces and cars. Subjects learned to discriminate pairs of similar faces and similar cars and to associate them with neutral responses. The stimulus pairs were presented upright, inverted, and additionally in two intermediate orientations. We found that discrimination performance was generally better for faces than for cars and that associations were learned faster for faces than for cars. However, we did not find any evidence that rotation affected discrimination and association processes for faces differently than for cars. In this sense, our results provide no evidence for the hypothesis that memory processes are responsible for the disproportionate effect of inversion which is found in recognition experiments

The influence of inversion on the judgment of facial and non-facial attributes

We investigated how inversion affects the interstimulus differences of faces and non-faces, as defined in terms of stimulus attributes. Ten faces were presented, both upright and upside-down, to 85 subjects. The subjects were asked to rate the faces according to their perceived trustworthiness (Experiment 1) and perceived age (Experiment 2). To 42 of the subjects we also presented ten cars, again upright and upside-down, and asked them to rate the cars according to their perceived elegance (Experiment 3). For each stimulus class and each attribute, we compared the subjects' ratings across orientations. Inversion decreased the differences between the faces' scores and, although to a much lesser extent, also decreased the differences between the cars' scores. For both stimulus classes, we found this effect of inversion to be regular, as reflected in an approximately linear relationship between the two orientations' scores. These results are discussed with respect to current theories of face perception, which claim that different information is processed in upright and inverted faces