Contamination from mortars and mills during laboratory crushing and pulverizing

Yamasaki, Toru

doi:10.9795/bullgsj.69.201

Cited by 12 publications

(4 citation statements)

References 14 publications

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“…Moreover, it was easy to apply sterilizing ethanol and flaming to the large, solid sub-samples (a surface sterilization technique that would be inappropriate for small or granular samples with larger surface area-to-volume ratios). Before analysis, most of our sub-samples required pulverization, which exposes the internal portions of a solid sample, making the sample vulnerable to environmental contamination as well as direct contamination from the pulverizing instrument [67] , [68] . Our pulverization method was a compromise between being able to process large samples to certain particle sizes (using a custom-made pulverizer) and managing contamination (by using various methods to decontaminate the samples, the instruments, and the immediate workspace).…”

Section: Discussionmentioning

confidence: 99%

Urban endoliths: incidental microbial communities occurring inside concrete

et al. 2023

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<abstract> <p>Concrete is now a prevalent type of synthetic rock, and its production and usage have major environmental implications. Yet, assessments of ordinary concrete have rarely considered that concrete itself is potential habitat for a globally important microbial guild, the endolithic microbes, which live inside rocks and other mineralized substrates. We sought evidence that many common concrete structures harbor endolithic microbial communities and that these communities vary widely depending on the conditions imposed by the concrete. In Summer 2022, we obtained samples from various concrete structures found throughout Lubbock, Texas, USA and subjected the internal (non-surface) portions of each sample to controlled microbial life detection tests including culture tests, DNA quantifications, DNA amplification tests, and ATP assays. The great preponderance of positive life detection results from our concrete samples suggests that most modern concrete hosts cryptic endolith communities composed of bacteria, sometimes co-occurring with fungi and/or archaea. Moreover, many of these microbes are viable, culturable, and identifiable via genetic analysis. Endolith signatures varied widely across concrete samples; some samples only yielded trace evidence of possibly dormant microbes while other samples contained much more microbial biomass and diversity, on par with some low-biomass soils. Pre-cast masonry units and fragments of poured concrete found underwater generally had the most endolith signatures, suggesting that concrete forms and environmental positioning affect endolithy. Endolith biosignatures were generally greater in less dense and less alkaline concrete samples. So, concrete endolith communities may be as ubiquitous and diverse as the concrete structures they inhabit. We propose further research of concrete endoliths to help clarify the role of modern concrete in our rapidly urbanizing biosphere.</p> </abstract>

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Section: Discussionmentioning

confidence: 99%

Urban endoliths: incidental microbial communities occurring inside concrete

et al. 2023

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“…The presence of cobalt can also be attributed to the sample preparation process which used tungsten carbide milling ( Yamasaki, 2018 ). This would explain the presence of cobalt in all AS samples.…”

Section: Discussionmentioning

confidence: 99%

What Do Safety Data Sheets for Artificial Stone Products Tell Us About Composition? A Comparative Analysis with Physicochemical Data

Kumarasamy

Pisaniello

Gaskin

et al. 2022

Annals of Work Exposures and Health

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Artificial stone (AS) is a composite material that has seen widespread use in construction, particularly for kitchen benchtops. However, fabrication processes with AS have been associated with serious lung disease. Safety data sheets (SDSs) aim to provide important information pertaining to composition and health risks. In the case of a complex mixture, SDSs may be problematic in terms of specific information on overall health risks. To assess this issue, we compared empirically determined mineral, metallic, and organic resin content of 25 individual AS products across six suppliers, with the corresponding SDS information. X-ray diffraction was used to quantitate the mineralogical components of AS samples, and X-ray fluorescence was used to estimate the metallic components. Organic material (resin content) was estimated using weight loss during calcination. Although the resin content for all AS samples was within the SDS-reported ranges, there was considerable variability in the crystalline silica content when comparing with supplier’s SDS. Potentially toxicologically relevant metallic and mineral constituents were not reported. Some supplier SDSs were found to provide more information than others. Only one of the six suppliers provided crystalline mineral content other than silica, and only two suppliers provided any information about metals. There remains a limited understanding of lung pathogenesis from AS, and this study highlights the need for more comprehensive and standardized SDS information for risk assessment and management.

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“…Powdered samples were provided by Paul Wignall: these had been ground in a tungsten ball mill to a fine powder. The only significant contaminants from tungsten ball mills are tungsten and cobalt (Roser et al, 2003; Yamasaki, 2018). All cobalt analyses and ratios must therefore be suspect: tungsten was not measured.…”

Section: Samples and Methodsmentioning

confidence: 99%