On November 9 and 10, 2015, the International Conference on Mesothelioma in Populations Exposed to Naturally Occurring Asbestiform Fibers was held at the University of Hawaii Cancer Center in Honolulu, Hawaii. The meeting was cosponsored by the International Association for the Study of Lung Cancer, and the agenda was designed with significant input from staff at the U.S. National Cancer Institute and National Institute of Environmental Health Sciences. A multidisciplinary group of participants presented updates reflecting a range of disciplinary perspectives, including mineralogy, geology, epidemiology, toxicology, biochemistry, molecular biology, genetics, public health, and clinical oncology. The group identified knowledge gaps that are barriers to preventing and treating malignant mesothelioma (MM) and the required next steps to address barriers. This manuscript reports the group’s efforts and focus on strategies to limit risk to the population and reduce the incidence of MM. Four main topics were explored: genetic risk, environmental exposure, biomarkers, and clinical interventions. Genetics plays a critical role in MM when the disease occurs in carriers of germline BRCA1 associated protein 1 mutations. Moreover, it appears likely that, in addition to BRCA1 associated protein 1, other yet unknown genetic variants may also influence the individual risk for development of MM, especially after exposure to asbestos and related mineral fibers. MM is an almost entirely preventable malignancy as it is most often caused by exposure to commercial asbestos or mineral fibers with asbestos-like health effects, such as erionite. In the past in North America and in Europe, the most prominent source of exposure was related to occupation. Present regulations have reduced occupational exposure in these countries; however, some people continue to be exposed to previously installed asbestos in older construction and other settings. Moreover, an increasing number of people are being exposed in rural areas that contain noncommercial asbestos, erionite, and other mineral fibers in soil or rock (termed naturally occurring asbestos [NOA]) and are being developed. Public health authorities, scientists, residents, and other affected groups must work together in the areas where exposure to asbestos, including NOA, has been documented in the environment to mitigate or reduce this exposure. Although a blood biomarker validated to be effective for use in screening and identifying MM at an early stage in asbestos/ NOA-exposed populations is not currently available, novel biomarkers presented at the meeting, such as high mobility group box 1 and fibulin-3, are promising. There was general agreement that current treatment for MM, which is based on surgery and standard chemotherapy, has a modest effect on the overall survival (OS), which remains dismal. Additionally, although much needed novel therapeutic approaches for MM are being developed and explored in clinical trials, there is a critical need to invest in prevention research, in whic...

Soil sulfates are present in arid and hyperarid environments on Earth and have been found to be abundant in soils on Mars. Examination of soil gypsum from the Atacama Desert, Chile, the Mojave Desert, United States, and Al‐Jafr Basin, Jordan, revealed endolithic cyanobacteria communities just below the surface of soil gypsum samples. Optical and scanning electron microscope observations of the colonized layers indicated that the unicellular Chroococcidiopsis is the dominant cyanobacterium in all studied communities. 16S rRNA gene analysis revealed that in addition to Chroococcidiopsis, a few other cyanobacteria are present. Heterotrophic bacteria are also abundant in the colonized zones of the fine‐grained gypsum from the Atacama and Mojave Desert, but insignificant in the fibrous gypsum from the Jordan Desert. Endolithic life forms similar to these described here may exist or have existed on Mars and should be targeted by the Mars Science Laboratory and future in situ missions.

Background Inhalation of asbestos and other mineral fibers are known causes of malignant mesothelioma (MM) and lung cancers. In a setting of occupational exposure to asbestos, MM occurs 4–8 times more frequently in men than in women, at the median age of 74 years, while an environmental exposure to asbestos causes the same number of MMs in men and women, at younger ages. Methods We studied the geology of Nevada to identify mineral fibers in the environment. We compared MM mortality in different Nevada Counties, per sex and age group, for the 1999–2010 period. Results We identified the presence of carcinogenic minerals in Nevada, including actinolite asbestos, erionite, winchite, magnesioriebeckite and richterite. We discovered that, compared with the US and other Nevada counties, Clark and Nye counties, in southern Nevada, had a significantly higher proportion of MM that occurred in young individuals (<55 years) and in women. Conclusions The elevated percentage of women and individuals younger than 55 years old, combined with a sex ratio of 1:1 in this age group and the presence of naturally occurring asbestos, suggests that environmental exposure to mineral fibers in southern Nevada may be contributing to some of these mesotheliomas. Further research to assess environmental exposures should allow the development of strategies to minimize exposure, as the development of rural areas continues in Nevada, and to prevent MM and other asbestos-related diseases.

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Biological soil crusts (BSCs) are bio-sedimentary complexes that play critical ecological roles in arid landscapes; however, the interactions between component biota and sediments are poorly understood. A detailed micromorphological investigation of BSC development and crust microstructure in the Muddy Mountains Wilderness Area, Nevada, examined features in thin section using pétrographie microscopy, light microscopy, scanning electron microscopy, and energy dispersive x-ray spectroscopy. The >1800 microscopic observations were linked to crust macroscale features and soil geomorphology. Complex bio-sedimentary structures of BSCs reflect a dynamic genetic history and diverse formative processes, including: (i) stabilization and authigenic mineral precipitation; (ii) wetting-drying and expansion-contraction; (iii) dust capture; (iv) microscale mass wasting; and (v) vesicular (Av) horizon formation. A new conceptual model for hot deserts illustrates how these processes co-develop with BSC succession, during countless wet-dry cycles, to huild up pinnacle microtopography while simultaneously forming Av horizons in the bio-rich and hio-poor zones. Complex surficial and internal hio-sedimentary structures, which vary as a function of crust morphology, trap surface water for uptake hy crust organisms, while dust influx provides a source of nutrients. These phenomena influence landscape-scale water dynamics and biogeochemical cycling, increasing the availability of soil resources during times of biotic stress. Biological soil crusts uniquely facilitate the accumulation, morphology, and ecosystem function of dust and should, therefore, be considered critical agents in arid pedogenesis and landscape development.Abbreviations: BSC, biological soil crust; EPS, extracellular polymeric secretions; XPL, cross-polarized light.

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Gypsum-bearing growth strata and sedimentary facies of the Moenkopi Formation on the crest and NE flank of the Castle Valley salt wall in the Paradox Basin record salt rise, evaporite exposure, and salt-withdrawal subsidence during the Early Triassic. Detrital gypsum and dolomite clasts derived from the middle Pennsylvanian Paradox Formation were deposited in strata within a few kilometers of the salt wall and indicate that salt rise rates roughly balanced sediment accumulation, resulting in long-term exposure of mobile evaporite. Deposition took place primarily in flood-basin or inland sabkha settings that alternated between shallow subaqueous and subaerial conditions in a hyperarid climate. Matrix-supported and clast-supported conglomerates with gypsum fragments represent debris-flow deposits and reworked debris-flow deposits, respectively, interbedded with flood-basin sandstone and siltstone during development of diapiric topography. Mudstonerich flood-basin deposits with numerous stage I to III gypsic paleosols capped by eolian gypsum sand sheets accumulated during waning salt-withdrawal subsidence. Association of detrital gypsum, eolian gypsum, and gypsic paleosols suggests that the salt wall provided a common source for gypsum in the surrounding strata. This study documents a previously unrecognized salt weld with associated growth strata containing diapir-derived detritus and gypsic palesols that can be used to interpret halokinesis.

Some of the most emissive surfaces on Earth are dominated by salt minerals. We hypothesized that the vulnerability of surfaces to eolian erosion may be controlled by salt mineralogy and crystal habit. We used x-ray diffractometry (XRD) and scanning electron microscopy-energy dispersive x-ray spectrometry (SEM-EDS) analyses to measure salt mineral assemblages and crystal habits along exposed shorelines of the Saltón Sea, California. Potential dust emissions were also measured using the Portable In-Situ Wind Erosion Lab (PI-SVi'ERL). Results indicate that surfaces with the highest emissions, up to ~1 mg m"^ s"', are composed of hydrous/anhydrous salt minerals and minerals with acicular or prismatic crystal habits. Hydrous/anhydrous minerals (mirabilite/thenardite, eugsterite/glauberite, gypsum/bassanite, and numerous Mg sulfates) are more unstable under changing environmental conditions, are likely to dissolve and reprecipitate repeatedly, form less cohesive tiny individual crystals ot small aggregates, and are therefore more likely to result in highly emissive surfaces. Salt minerals with acicular or prismatic habits are more likely to be disruptive, enhance salt heave, lessen the degree of interlocking precipitates, and form loose, "puffy" crusts that are highly emissive. Low-sloping surfaces near the shoreline had greater fluctuations in water content and relative humidity, tri^ering frequent salt mineral dissolution-precipitation and increased emissions. A high water table also allowed a continuously replenishing supply of salt ctystals, increasing the potential for extensive dust emissions. Surfaces containing salt minerals are incredibly dynamic, but understanding the processes that control surface characteristics is an important step in mitigating dust emissions.Abbreviations: PI-SWERL, Portable In-Situ Wind Erosion Lab; PM,(,, particulate matter with a <10-|j,m aerodynamic diameter; SEM-EDS, scanning electron microscopy-energy dispersive x-ray spectrometry; XRD, x-ray diíFractometry.