Publications by authors named "R Scroggins"

Increased use of nano-cerium oxide (nCeO) in an array of industrial applications has raised environmental concerns due to potential increased loadings to the soil environment. This research investigated the potential adverse effects of nCeO (10-30 nm) on the soil microbial community in two exposure scenarios: direct application to soil, and indirect application to soil through chemical spiking of biosolids, followed by mixing into soil. Total Ce in test soils without, and with biosolids amendment, ranged from 44 to 770, and 73 to 664 mg Ce kg soil, respectively.

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Article Synopsis
  • The research focused on the effects of copper oxide nanoparticles (nCuO) in soil, using earthworms and springtails to assess toxicity and bioaccumulation, comparing nCuO with soluble copper sulfate (CuSO).
  • Toxicity levels were found to be similar between nCuO and CuSO for springtails, but earthworm reproduction was significantly impacted by both forms, indicating particle dissolution in soil likely drives toxicity.
  • The study highlights that current risk assessment methods for trace metals can apply to nCuO, yet emphasizes the importance of particle dissolution rates in varying soil conditions when evaluating environmental impact.
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This study represents a holistic approach in assessing the effects of copper oxide nanoparticles (nCuO) on microbial health and community structure in soil amended with municipal biosolids. The biosolids were amended with nCuO (<50 nm) and mixed into a sandy loam soil at measured Cu concentrations of 27, 54, 123, 265 and 627 mg Cu kg soil. A suite of tests were used to assess the potential impact of nCuO on microbial growth, activity, and diversity.

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The use of neonicotinoids in agriculture is a critical environmental protection issue. Although there has been considerable research on pollinator exposure and aquatic toxicological effects, few studies have investigated the chronic impacts on soil-dwelling species. Given the application of neonicotinoids into soil systems, there is the potential for risk to soil invertebrates.

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Identification of bacteria in new or existing commercial microbial-based products (MBPs) is important for compliance with government regulations and for human and environmental risk assessment. Research was performed to develop effective methods to identify bacteria present in a MBP using a combined approach of conventional enrichment culture technique and denaturing gradient gel electrophoresis (DGGE) followed by clonal sequencing or next generation sequencing (NGS). Genomic DNA obtained from un-enriched or enriched MBP in MacConkey broth, Azide Dextrose broth, Peptone Water mixed with Polymixine B and Gram Negative (GN) media under three different temperatures (22 °C, 28 °C and 37 °C) were sequenced in two methods for the V3 and V6 hypersensitive regions of 16S ribosomal DNA (rDNA) and compared.

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