Quantification of the pathological response and fate in the lung and pleura of chrysotile in combination with fine particles compared to amosite-asbestos following short-term inhalation exposure

The marked difference in biopersistence and pathological response between chrysotile and amphibole asbestos has been well documented. This study is unique in that it has examined a commercial chrysotile product that was used as a joint compound. The pathological response was quantified in the lung and translocation of fibers to and pathological response in the pleural cavity determined. This paper presents the final results from the study. Rats were exposed by inhalation 6 h/day for 5 days to a well-defined fiber aerosol. Subgroups were examined through 1 year. The translocation to and pathological response in the pleura was examined by scanning electron microscopy and confocal microscopy (CM) using noninvasive methods.The number and size of fibers was quantified using transmission electron microscopy and CM. This is the first study to use such techniques to characterize fiber translocation to and the response of the pleural cavity. Amosite fibers were found to remain partly or fully imbedded in the interstitial space through 1 year and quickly produced granulomas (0 days) and interstitial fibrosis (28 days). Amosite fibers were observed penetrating the visceral pleural wall and were found on the parietal pleural within 7 days postexposure with a concomitant inflammatory response seen by 14 days. Pleural fibrin deposition, fibrosis, and adhesions were observed, similar to that reported in humans in response to amphibole asbestos. No cellular or inflammatory response was observed in the lung or the pleural cavity in response to the chrysotile and sanded particles (CSP) exposure. These results provide confirmation of the important differences between CSP and amphibole asbestos

Informal Participatory Platforms for Adaptive Management. Insights into Niche-finding, Collaborative Design and Outcomes from a Participatory Process in te Rhine Basin

New regulatory water management requirements on an international level increasingly challenge the capacity of regional water managers to adapt. Stakeholder participation can contribute to dealing with these challenges because it facilitates the incorporation of various forms of knowledge and interests into policy-making and decision-making processes. Also, by providing space for informal multistakeholder platforms, management experiments can be established more easily in rigid regulatory settings, allowing for social learning to take place. Stakeholder participation is currently stipulated by several legal provisions, such as the Water Framework Directive, which plays an increasingly important role in European water management. Drawing on recent experiences in a participatory process in the German Dhuenn basin, a sub-basin of the river Rhine, we explored the interplay of informal and formal settings in a participatory process. To what degree can we allow for openness and catalyze social learning in participatory processes grounded in formal management structures? To what degree can results of informal processes have an impact on practice? We analyzed three major challenges related to this interplay: (1) the niche-finding process to establish a participatory platform; (2) the co-design process by water management practitioners, researchers and consultants; and (3) the tangible outputs and learning. We found that niches for the establishment of informal participatory platforms can occur even in a rigid and strongly structured administrative environment. Further, our case study shows that collaborative process design fosters dealing with uncertainties. We conclude that in an effective participatory process, a balance should be struck between informality and formal institutional structures to catalyze experimentation and learning and to ensure that process results have an impact on management decision

Influence of surface wettability on methane hydrate formation in hydrophilic and hydrophobic mesoporous silicas

The methane hydrate MH formation process in confinement was investigated using high pressure methane sorption experiments on two wet materials with similar pore size distributions, B PMO hydrophobic and MCM 41 hydrophilic . Their methane sorption isotherms possess two discrete methane gas consumption steps at 10 bar and 30 bar at 243 K. A systematic analysis reveals that external water and the so called core water inside the pore is rapidly consumed in the first step to form bulk like hydrate, whereas adsorbed water is slowly consumed in the second step to form less stable confined hydrates at higher pressures. Synchrotron powder X Ray results confirm methane hydrate structure I and reveal that bulk ice is swiftly and fully converted to hydrate in MCM 41, whereas inactive bulk ice co exists with MH in B PMO at 6 MPa demonstrating the huge impact of the surface wettability on the water s behavior during MH formatio