Browsing by Author "Kroetch, Kimberly"
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Item Estimated discharge of microplastics via urban stormwater during individual rain events(2023) Ross, Matthew S.; Loutan, Alyssa; Groeneveld, Tianna M.; Molenaar, Danielle; Kroetch, Kimberly; Bujaczek, Taylor; Kolter, Sheldon; Moon, Sarah; Huynh, Alan; Khayam, Rosita; Franczak, Brian C.Urban stormwater runoff is an important pathway for the introduction of microplastics and other anthropogenic pollutants into aquatic environments. Highly variable concentrations of microplastics have been reported globally in runoff, but knowledge of key factors within urban environments contributing to this variability remains limited. Furthermore, few studies to date have quantitatively assessed the release of microplastics to receiving waters via runoff. The objectives of this study were to assess the influence of different catchment characteristics on the type and amount of microplastics in runoff and to provide an estimate of the quantity of microplastics discharged during rain events. Stormwater samples were collected during both dry periods (baseflow) and rain events from 15 locations throughout the city of Calgary, Canada’s fourth largest city.Item Estimated discharge of microplastics via urban stormwater during individual rain events(2023) Ross, Matthew S.; Loutan, Alyssa; Groeneveld, Tianna M.; Molenaar, Danielle; Kroetch, Kimberly; Bujaczek, Taylor; Kolter, Sheldon; Moon, Sarah; Franczak, Brian C.Urban stormwater runoff is an important pathway for the introduction of microplastics and other anthropogenic pollutants into aquatic environments. Highly variable concentrations of microplastics have been reported globally in runoff, but knowledge of key factors within urban environments contributing to this variability remains limited. Furthermore, few studies to date have quantitatively assessed the release of microplastics to receiving waters via runoff. The objectives of this study were to assess the influence of different catchment characteristics on the type and amount of microplastics in runoff and to provide an estimate of the quantity of microplastics discharged during rain events. Stormwater samples were collected during both dry periods (baseflow) and rain events from 15 locations throughout the city of Calgary, Canada’s fourth largest city. These catchments ranged in size and contained different types of predominant land use. Microplastics were found in all samples, with total concentrations ranging from 0.7 to 200.4 pcs/L (mean = 31.9 pcs/L). Fibers were the most prevalent morphology identified (47.7 ± 33.0%), and the greatest percentage of microplastics were found in the 125–250 µm size range (26.6 ± 22.9%) followed by the 37–125 µm size range (24.0 ± 22.3%). Particles were predominantly black (33.5 ± 33.8%), transparent (22.6 ± 31.3%), or blue (16.0 ± 21.6%). Total concentrations, dominant morphologies, and size distributions of microplastics differed between rain events and baseflow, with smaller particles and higher concentrations being found during rain events. Concentrations did not differ significantly amongst catchments with different land use types, but concentrations were positively correlated with maximum runoff flow rate, catchment size, and the percentage of impervious surface area within a catchment. Combining microplastic concentrations with hydrograph data collected during rain events, we estimated that individual outfalls discharged between 1.9 million to 9.6 billion microplastics to receiving waters per rain event. These results provide further evidence that urban stormwater runoff is a significant pathway for the introduction of microplastics into aquatic environments and suggests that mitigation strategies for microplastic pollution should focus on larger urbanized catchments.Item Lennon v. McCartney(2020) Kroetch, KimberlyIn this analysis, the chord progressions used in songs by the Beatles are modelled as Markov chains to identify potential differences between songs for which John Lennon had more influence and those for which Paul McCartney had more influence. A preliminary comparison of random samples of songs from each artist did not identify noteworthy differences between Lennon and McCartney; most pieces resulted in regular Markov chains. This analysis then focusses on two songs from the Beatles – “Norwegian Wood”, primarily written by John Lennon, and “Good Day Sunshine”, primarily written by Paul McCartney – which deviated from this pattern. Similar patterns were found between the two songs despite major differences in the chords that made up each state space. In general, however, McCartney’s song had more variety in terms of the number of chords used and the paths taken between tonic chords.Item A prospective observational study of persistent opioid use after complex foot and ankle surgery(2022) Verrier, Michelle; Niu, Shuang; Kroetch, Kimberly; Buro, Karen; Douglas, Chris; Green, James; Pedersen, Mary E.; Dillane, DerekThe incidence of persistent postsurgical opioid use (PPOU) after complex foot and ankle surgery is unknown. We aimed to determine the incidence and characteristics of PPOU in opioid-naı¨ve, occasional, and regular opioid users at baseline and at six weeks, three months, and six months postoperatively.