Dimethylsilanediol (DMSD) is a primary degradation product of silicone materials in the environment. Due to its low air/water partition coefficient and low soil/water distribution coefficient, this compound is not expected to undergo sorption and volatilization in wet soil. In an accompanying paper, we confirm that under controlled indoor conditions in test tubes, there is little to no volatilization of DMSD from soil and soil constituents if soil is wet. However, a significant amount of DMSD was volatilized when the soil substrates became air dried. Given the importance of water on the partition and fate of DMSD, we now report a continuation of this study focusing on the relation between DMSD removal and water loss in re-constituted soil columns under outdoor conditions. Consistent with predictions based on its partition properties and reconciling this evidence with previously reported field and laboratory studies, DMSD distribution was found to be largely dependent on water partitioning. The results suggested that DMSD moved upward in soil profile as soil water was evaporated from topmost layers with little DMSD retention by the soil matrix. As soil dried, a fraction of DMSD was sorbed by the soil matrix in the topmost layer, while most of the spiked radio-labeled DMSD was removed from soil through volatilization.
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http://dx.doi.org/10.1016/j.chemosphere.2024.141478 | DOI Listing |
Proc Natl Acad Sci U S A
January 2025
Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA 94550.
In soils, the first rain after a prolonged dry period represents a major pulse event impacting soil microbial community function, yet we lack a full understanding of the genomic traits associated with the microbial response to rewetting. Genomic traits such as codon usage bias and genome size have been linked to bacterial growth in soils-however, often through measurements in culture. Here, we used metagenome-assembled genomes (MAGs) with O-water stable isotope probing and metatranscriptomics to track genomic traits associated with growth and transcription of soil microorganisms over one week following rewetting of a grassland soil.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
Laboratoire de Géologie, Ecole Normale Supérieure, CNRS, Institut Pierre-Simon Laplace, Université Paris Sciences et Lettres, Paris 75005, France.
The insulative properties of soil organic carbon (SOC) and surface organic layers (moss, lichens, litter) regulate surface-atmosphere energy exchanges in the Arctic through a coupling with soil temperatures. However, a physical description of this process is lacking in many climate models, potentially biasing their high-latitude climate predictions. Using a coupled surface-atmosphere model, we identified a strong feedback loop between soil insulation, surface air temperature, and snowfall.
View Article and Find Full Text PDFEnviron Health Perspect
January 2025
Department of Epidemiology, Biostatistics, and Environmental Health, School of Public Health, University of Nevada, Reno, Reno, Nevada, USA.
Background: Coccidioidomycosis, caused by inhalation of spp. spores, is an emerging infectious disease that is increasing in incidence throughout the southwestern US. The pathogen is soil-dwelling, and spore dispersal and human exposure are thought to co-occur with airborne mineral dust exposures, yet fundamental exposure-response relationships have not been conclusively estimated.
View Article and Find Full Text PDFPLoS One
January 2025
Sustainability and Environmental Education, Goshen College, Goshen, IN, United States of America.
Human exposure to mycotoxins is common and often severe in underregulated maize-based food systems. This study explored how monitoring of these systems could help to identify when and where outbreaks occur and inform potential mitigation efforts. Within a maize smallholder system in Kongwa District, Tanzania, we performed two food surveys of mycotoxin contamination at local grain mills, documenting high levels of aflatoxins and fumonisins in maize destined for human consumption.
View Article and Find Full Text PDFPLoS One
January 2025
Ltd Project Construction Management Company, Jiangxi Provincial Communications Investment Group Co., Nanchang, China.
The impact of interlayer shear stress on the distribution of earth pressure in cohesive soil is notable, but currently, there lacks a comprehensive theory that integrates this factor in the calculation of active earth pressure. Drawing from the Mohr stress circle specific to clay soils, a formula to calculate interlayer shear stress has been derived. Moreover, a robust model has been formulated to compute the active earth pressure in clay soils, incorporating elements such as interlayer shear stress, effects of displacement, soil arching, and the morphology of the sliding surface.
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