Gebel T.,Federal Institute for Occupational Safety and Health
Archives of Toxicology | Year: 2012
Materials that can be described as respirable granular biodurable particles without known significant specific toxicity (GBP) show a common mode of toxicological action that is characterized by inflammation and carcinogenicity in chronic inhalation studies in the rat. This study was carried out to compare the carcinogenic potency of GBP nanomaterials (primary particle diameter 1-100 nm) to GBP micromaterials (primary particle diameter >100 nm) in a pooled approach. For this purpose, the positive GBP rat inhalation carcinogenicity studies have been evaluated. Inhalation studies on diesel engine emissions have also been included due to the fact that themode of carcinogenic action is assumed to be the same.As it is currently not clear which dose metrics may best explain carcinogenic potency, different metrics have been considered. Cumulative exposure concentrations related to mass, surface area, and primary particle volume have been included as well as cumulative lung burden metrics related to mass, surface area, and primary particle volume. In total, 36 comparisons have been conducted. Including all dose metrics, GBP nanomaterials were 1.33- to 1.69-fold (mean values) and 1.88- to 3.54-fold (median values) more potent with respect to carcinogenicity than GBP micromaterials, respectively. Nine of these 36 comparisons showed statistical significance (p<0.05, U test), all of which related to dosemetrics based on particlemass. Themaximum comparative potency factor obtained for one of these 9 dose metric comparisons based on particle mass was 4.71. The studies with diesel engine emissions did not have a major impact on the potency comparison. The average duration of the carcinogenicity studies with GBP nanomaterials was 4 months longer (median values 30 vs. 26 months) than the studies with GBP micromaterials, respectively. Tumor rates increase with age and lung tumors in the rat induced by GBP materials are known to appear late, that is, mainly after study durations longer than 24 months. Taking the different study durations into account, the real potency differences were estimated to be twofold lower than the relative potency factors identified. In conclusion, the chronic rat inhalation studies with GBP materials indicate that the difference in carcinogenic potency between GBP nanomaterials and GBP micromaterials is low can be described by a factor of 2-2.5 referring to the dose metrics mass concentration. © Springer-Verlag 2012.
Raduntz T.,Federal Institute for Occupational Safety and Health
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2016
Complex and highly automated systems impose high demands on employees with respect to cognitive capacity and the ability to cope with workload. Objectively registering mental workload at workplaces with high cognitive demands would enable prevention of overand underload. Although urgently needed, such technical measurement is currently unfeasible. Hence, the goal of this work is the establishment of precisely such an objective method. In this article we briefly present a new method for registering mental workload by means of the electroencephalogram (EEG). Based on so called Dual Frequency Head Maps (DFHM) every 5 s we obtain an index of mental state ranging between the classes low, moderate, and high workload. Finally, we present results from a sample set of 54 people during the execution of the cognitive tasks 0-back, stroop test and AOSPAN in a laboratory setting. We compare them with our expectations based on the knowledge of task requirements on the executive functions as well as with further workload relevant biosignal data, performance data, and the NASA-TLX as a subjective questionnaire method. By this we gain proof of the integrity of the new method. © Springer International Publishing Switzerland 2016.
Gebel T.,Federal Institute for Occupational Safety and Health
Archives of Toxicology | Year: 2013
The evaluations in Gebel (Arch Toxicol 86(7):995-1007, 2012) were carried out according to established procedures in regulatory toxicology. The variability in the available data was taken into account. The quality of the underlying data set should not be overestimated. The relevant conclusion in Gebel (Arch Toxicol 86(7):995-1007, 2012) is that the difference in carcinogenic potency comparing nanosized to microsized respirable granular biodurable particles without known significant specific toxicity (GBP) is low and lower than previously estimated. © 2013 Springer-Verlag Berlin Heidelberg.
Jakob M.,Leibniz Institute for Agricultural Engineering |
Liebers F.,Federal Institute for Occupational Safety and Health
Journal of Agromedicine | Year: 2011
Large-herd dairy operations utilize parlor milking systems that reduce the physical workload in comparison to tethering systems. Nevertheless, the number of musculoskeletal disorders among workers on dairy farms is not decreasing. In response, a study was carried out to measure the workload focusing on the impact of working height and weight of the milking unit. In this article a new quarter individual milking unit without claw and using single-tube guidance is compared with a light (1.4 kg) conventional unit. A significant reduction of muscular load as well as the reduction of process time was measured using the quarter individual system. Body posture was also recorded using video-based motion analysis. Based on these results, the new system is expected to significantly improve the work place in modern milking parlors by reducing extreme postures as well as the physical and static musculoskeletal load. © Taylor & Francis Group, LLC.
Hug K.,Institute of Tropical Medicine |
Grize L.,Institute of Tropical Medicine |
Seidler A.,Federal Institute for Occupational Safety and Health |
Kaatsch P.,University of Mainz |
Schuz J.,Danish Cancer Society
American Journal of Epidemiology | Year: 2010
Extremely low frequency magnetic fields (ELF-MFs) have been classified as possibly carcinogenic to humans by the International Agency for Research on Cancer. The authors investigated, in a population-based case-control study in Germany, if children whose parents were exposed preconceptionally at work to ELF-MFs had an increased risk of developing cancer. Cases aged 0-14 years were ascertained from the German Childhood Cancer Registry. Controls were selected from local resident registration offices. The parental occupational history was recorded in questionnaires and telephone interviews, and preconceptional magnetic field exposure was estimated according to a job-exposure matrix. The analysis included 2,382 controls and 2,049 cases (846 children with acute leukemia, 159 children with non-Hodgkin's lymphoma, 444 children with central nervous system tumors, and 600 children with other solid tumors). Frequency-matched conditional logistic regression models revealed no increased cancer risks in children whose fathers were occupationally exposed to magnetic fields above 0.2 μT. Additionally, there was no evidence for a risk increase at magnetic field levels exceeding 1 μT. Based on much smaller numbers, maternal occupational exposure was also not related to increased cancer risks. In this large case-control study, the risk of childhood cancer was not linked to preconceptional parental ELF-MF exposure.