Browsing by Author "Shukle, John"

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    Addressing Risks of Lead in Water and Soil: Using Citizen Science and a Unique Partnership with Faith Organizations
    (ENGAGE! Co-created Knowledge Serving the City, 2021-10-12) Filippelli, Gabriel; Hicks, Ivan; Druschel, Gregory; Kelly, Jason M.; Shukle, John; Strout, Spencer; Nichols, Natalie; Stroud, Dawson; Ottenweller, Megan; Ohrberg, Makayla; Longbrake, Marisa; Wood, Leah; Clark, Benjamin; Fryling, Kevin
    One of the most widespread environmental health hazards in the United States remains exposure to the harmful neurotoxin lead. So much lead remains in the urban environment that it is not unusual to find neighborhoods where more than 10% of children exhibit harmful levels of lead, compared to the national average of about 1%. To overcome this challenge, a partnership between IUPUI researchers and faith organizations in Indianapolis is taking aim at the risk of household lead contamination by providing residents the tools they need to protect against it. The community-driven science aspect of this project is intentional—not only will the individuals who participate benefit directly, but the resulting data will also play a role in keeping communities safer more broadly.
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    Mapping the Urban Lead Exposome: A Detailed Analysis of Soil Metal Concentrations at the Household Scale Using Citizen Science
    (MDPI, 2018-07-19) Filippelli, Gabriel M.; Adamic, Jessica; Nichols, Deborah; Shukle, John; Frix, Emeline; Earth Sciences, School of Science
    An ambitious citizen science effort in the city of Indianapolis (IN, USA) led to the collection and analysis of a large number of samples at the property scale, facilitating the analysis of differences in soil metal concentrations as a function of property location (i.e., dripline, yard, and street) and location within the city. This effort indicated that dripline soils had substantially higher values of lead and zinc than other soil locations on a given property, and this pattern was heightened in properties nearer the urban core. Soil lead values typically exceeded the levels deemed safe for children’s play areas in the United States (<400 ppm), and almost always exceeded safe gardening guidelines (<200 ppm). As a whole, this study identified locations within properties and cities that exhibited the highest exposure risk to children, and also exhibited the power of citizen science to produce data at a spatial scale (i.e., within a property boundary), which is usually impossible to feasibly collect in a typical research study.
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    Sediment Disturbance Negatively Impacts Methanogen Abundance but Has Variable Effects on Total Methane Emissions
    (Frontiers Media, 2022-02-21) Rowe, Annette; Urbanic, Megan; Trutschel, Leah; Shukle, John; Druschel, Gregory; Booth, Michael; Earth and Environmental Sciences, School of Science
    Methane emissions from aquatic ecosystems are increasingly recognized as substantial, yet variable, contributions to global greenhouse gas emissions. This is in part due to the challenge of modeling biologic parameters that affect methane emissions from a wide range of sediments. For example, the impacts of fish bioturbation on methane emissions in the literature have been shown to result in a gradient of reduced to enhanced emissions from sediments. However, it is likely that variation in experimental fish density, and consequently the frequency of bioturbation by fish, impacts this outcome. To explore how the frequency of disturbance impacts the levels of methane emissions in our previous work we quantified greenhouse gas emissions in sediment microcosms treated with various frequencies of mechanical disturbance, analogous to different levels of activity in benthic feeding fish. Greenhouse gas emissions were largely driven by methane ebullition and were highest for the intermediate disturbance frequency (disturbance every 7 days). The lowest emissions were for the highest frequency treatment (3 days). This work investigated the corresponding impacts of disturbance treatments on the microbial communities associated with producing methane. In terms of total microbial community structure, no statistical difference was observed in the total community structure of any disturbance treatment (0, 3, 7, and 14 days) or sediment depth (1 and 3 cm) measured. Looking specifically at methanogenic Archaea however, a shift toward greater relative abundance of a putatively oxygen-tolerant methanogenic phylotype (ca. Methanothrix paradoxum) was observed for the highest frequency treatments and at depths impacted by disturbance (1 cm). Notably, quantitative analysis of ca. Methanothrix paradoxum demonstrated no change in abundance, suggesting disturbance negatively and preferentially impacted other methanogen populations, likely through oxygen exposure. This was further supported by a linear decrease in quantitative abundance of methanogens (assessed by qPCR of the mcrA gene), with increased disturbance frequency in bioturbated sediments (1 cm) as opposed to those below the zone of bioturbation (3 cm). However, total methane emissions were not simply a function of methanogen populations and were likely impacted by the residence time of methane in the lower frequency disturbance treatments. Low frequency mechanical disruption results in lower methane ebullition compared to higher frequency treatments, which in turn resulted in reduced overall methane release, likely through enhanced methanotrophic activities, though this could not be identified in this work. Overall, this work contributes to understanding how animal behavior may impact variation in greenhouse gas emissions and provides insight into how frequency of disturbance may impact emissions.