Background: The COVID-19 pandemic has continued to pose a major global public health risk. The importance of public health surveillance systems to monitor the spread and impact of COVID-19 has been well demonstrated. The purpose of this study was to describe the development and effectiveness of a real-time public health syndromic surveillance system (ACES Pandemic Tracker) as an early warning system and to provide situational awareness in response to the COVID-19 pandemic in Ontario, Canada.
View Article and Find Full Text PDFMorbidity and mortality from exposure to extreme cold highlight the need for meaningful temperature thresholds to activate public health alerts. We analyzed emergency department (ED) records for cold temperature-related visits collected by the Acute Care Enhanced Surveillance system-a syndromic surveillance system that captures data on ED visits from hospitals in Ontario-for geographic trends related to ambient winter temperature. We used 3 Early Aberration Reporting System algorithms of increasing sensitivity-C1, C2, and C3-to determine the temperature at which anomalous counts of cold temperature-related ED visits occurred in northern and southern Ontario from 2010 to 2016.
View Article and Find Full Text PDFObjective: To describe the associations between the socioeconomic status of emergency department (ED) users and age, sex, and acuity of medical conditions to better understand users' common characteristics, and to better meet primary and ambulatory health care needs.
Design: A retrospective, observational, population-based analysis. A rigorous proxy of socioeconomic status was applied using census-based methods to calculate a relative deprivation index.
Carbon isotope fractionation is of great interest in assessing chlorinated ethene transformation by nanoscale zero-valent iron at contaminated sites, particularly in distinguishing the effectiveness of an implemented abiotic degradation remediation scheme from intrinsic biotic degradation. Transformation of trichloroethylene (TCE), cis-dichloroethylene (cis-DCE), and vinyl chloride (VC) with two types of nanoscale iron materials showed different reactivity trends, but relatively consistent carbon isotope enrichment factors (epsilon) of -19.4 per thousand +/- 1.
View Article and Find Full Text PDFDegradation of 1,1- and 1,2-dichloroethane (1,1-DCA, 1,2-DCA) and carbon tetrachloride (CCl4) on Zn0 was investigated using compound specific isotope analysis (CSIA) to measure isotopic fractionation factors for chloroalkane degradation by hydrogenolysis, by alpha-elimination, and by beta-elimination. Significant differences in enrichment factors (epsilon) and associated apparent kinetic isotope effects (AKIE) were measured for these different reaction pathways, suggesting that carbon isotope fractionation by beta-elimination is substantially larger than fractionation by hydrogenolysis or by alpha-elimination. Specifically, for 1,1-DCA, the isotopic composition of the reductive alpha-elimination product (ethane) and the hydrogenolysis product (chloroethane) were the same, indicating that cleavage of a single C-Cl bond was the rate-limiting step in both cases.
View Article and Find Full Text PDFStable carbon isotopic analysis, in combination with compositional analysis, was used to evaluate the performance of an iron permeable reactive barrier (PRB) for the remediation of ground water contaminated with trichloroethene (TCE) at Spill Site 7 (SS7), F.E. Warren Air Force Base, Wyoming.
View Article and Find Full Text PDFFour samples of two commercially available iron brands used as substrate for iron permeable reactive barriers (PRBs) were tested for suitability for remediation of perchloroethylene (PCE), trichloroethylene (TCE), cis-dichloroethylene (cDCE) and vinyl chloride (VC). Kinetic studies indicate that rates of reaction are enhanced for cDCE and VC on Connelly iron (2.8 x 10(-4) to 6.
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