Environmental Public Health Commons^™

Association Of Fall-Related Injuries And Different Diagnoses In Older Adults Of Ontario: A Machine Learning Approach, Sorour Rostampour

Electronic Thesis and Dissertation Repository

Falls are the leading cause of injury-related hospitalizations among older adults in Canada. This study aimed to identify the most informative diagnostic categories associated with fall-related injuries (FRIs) using three machine learning algorithms: decision tree, random forest, and extreme gradient boosting tree (XGBoost). Secondary data from two Ontario health administrative databases (NACRS, DAD) covering the period 2006-2015 were analyzed. Older adults (aged ≥ 65 years) who sought treatment for FRIs in emergency departments (ED) or hospitals, as indicated by Canadian version of the 10th revision of the International Statistical Classification of Diseases and Related Health Problems (ICD-10-CA) codes for falls …

Examining Public Health Risk Communication Via Social Media By Provincial And Local Health Authorities In Ontario During The Covid-19 Pandemic, Marc Resendes

Electronic Thesis and Dissertation Repository

Risk communication campaigns are essential during public health crises to inform the public about ways to mitigate, alleviate and manage potential risks. The purpose of this study was to describe risk communication on social media by Ontarian health authorities amid COVID-19, in addition to examining the strategies that guided their social media use. This was completed through (a) a narrative review of risk communication literature; (b) a qualitative content analysis of select health authority Twitter messaging following three major COVID-19 milestones; and (c) key informant interviews with those coordinating social media responses to COVID-19. Information giving and news updates were …

Association Between Air Pollution And Incidence Of Dementia: A Systematic Review And Meta-Analysis Of Cohort Studies, Ehsan Abolhasani

Electronic Thesis and Dissertation Repository

Objective. To estimate the risk of dementia in association with exposure to air pollutants.

Methods. Six databases were searched. Cohort studies that reported the hazard ratio (HR) of dementia in association with exposure to air pollutants in adults > 40y were included. For all meta-analyses, the random-effects model was used.

Results. A total of 16 and 13 studies were included in the systematic review and the meta-analysis, respectively. Risk of dementia increased by 4% per 1μg/m³ increase in fine particulate matter level (HR, 1.04; 95%CI, [1.02, 1.06]), which was statistically significant. The risk of dementia increased by 3% per 10μg/m …

A Novel Spatio-Temporal Examination Of Children's Accessibility, Exposure, And Engagement To Parks And Recreation Spaces In Middlesex-London, Ontario, Malcolm K. Little

Electronic Thesis and Dissertation Repository

Children are spending more free time engaged in activities indoors, rather than in outdoor environments such as parks and recreation spaces. Parks and recreation spaces provide amenities that promote physical, cognitive, and social health among children. As it relates to the complexities of children’s living situations, properly measuring children’s levels of interactions with these spaces is poorly understood in geography research.

By examining various attributes of children, this thesis improves on the measurement of children’s levels of interactions with parks and recreation spaces. Research herein utilized household survey data, a high-resolution GIS dataset of environmental factors, and GPS logs from …

Magnetic Field Frequency-Response For Human Magnetophosphene Perception And Associated Eeg Modulations, Cadence M. Baker

Electronic Thesis and Dissertation Repository

Background: Magnetophosphenes are among the most reliably reported effects resulting from magnetic induction. The frequency dependence of the perception threshold is crucial, as guideline agencies use this information to set exposure limits whose purpose is to protect public and workers.

Objective:Establish the magnetophosphene perception thresholds throughout the extremely low frequency range (0-300 Hz) and evaluate the use of EEG as a biomarker.

Hypothesis:Perception thresholds will be lowest at ~30 Hz. EEG occipital alpha power will decrease upon perception.

Methods:60 participants were exposed to homogenous magnetic fields up to 300 Hz, and 70 mT. EEG alpha power …

Carbohydrates And Fungal Toxin Exposure Influence The Vaginal Microbiota, Metabolome, And Reproductive Health Of Women, Stephanie L. Collins

Electronic Thesis and Dissertation Repository

The reproductive health of women is influenced by microorganisms and their metabolites, namely those representing the vaginal microbiota and those producing toxins that are ingested. To manipulate the vaginal microbiota toward a health-associated, Lactobacillusdominant state, an approach adopting prebiotic lactulose was taken. Using batch culture, lactulose supported Lactobacillus maintenance and positively altered metabolites, while not disrupting indigenous L. crispatus epithelial adherence. The vagina also harbours abundant glycogen, but initial assumptions that lactobacilli utilize it were incorrect. I have now shown that glycogen selectively stimulates organisms associated with dysbiosis and L. iners in a self-limiting manner. Other compounds such as environmental …

Environmental Heat And Acute Kidney Injury In Older Adults: A Matched Case-Control Study, Rebecca K. Mctavish

Electronic Thesis and Dissertation Repository

This matched case-control study examined the association between environmental heat exposure and hospital encounters with acute kidney injury (AKI) among adults, 66 years and older, in the province of Ontario, Canada. We matched 52,913 cases who had an AKI event during the warm seasons (April to September) of 2005 to 2012 with 174,222 controls who did not have an AKI event. We matched cases to controls on date, age, sex, residential status, income, and history of chronic kidney disease using a variable one to four matching ratio. We classified heat periods as three consecutive days where the 95th percentile of …

A Link Between Paediatric Asthma And Obesity: Are They Caused By The Same Environmental Conditions?, Phylicia Gonsalves

Electronic Thesis and Dissertation Repository

The highly associated paediatric conditions of asthma and overweight have seen dramatic increases over the past few decades. This thesis explored air pollution exposure as a potential underlying mechanism of co-morbid asthma and overweight among adolescents aged 12 to 18 years. Data from the Canadian Community Health Survey were merged with a database containing estimates of air pollution as assessed by particulate matter ≤ 2.5 microns (PM_2.5) concentrations at the postal code centroid in southwestern Ontario. Logistic regression was used to conduct the analysis. Adolescents were more likely to be overweight as PM_2.5 concentrations increased. There was …

The Association Between The Neighbourhood Food Environment And Prevalence Of Three Chronic Diseases In Urban Canada: A Cross-Sectional Analysis, Jagraj Singh Pandher

Electronic Thesis and Dissertation Repository

Research on the association between the neighbourhood food environment and prevalence of chronic diseases is very limited in Canada. The objective of this thesis was to investigate: (i) the associations between the neighbourhood food environment and prevalence of type II diabetes, cardiovascular disease and hypertension among Canadian adults living in urban areas; and (ii) whether or not dietary patterns, obesity and physical activity mediate such associations. Self-reported diagnosis of three chronic diseases, and individual-level socio-demographic and lifestyle variables were taken from the 2009-2010 Canadian Community Health Survey; neighbourhood-level socio-economic data were taken from the 2011 National Household Survey; and the …

The Lunches Study: Elementary School Children's Packed Lunch Contents And Intake In The Traditional Vs. Balanced School Day Schedule, Lisa Neilson

Electronic Thesis and Dissertation Repository

The Balanced School Day (BSD), an alternative to the Traditional Schedule (TS), provides two 20-minute eating periods during the school day, rather than a midday lunch break. Widespread implementation of the BSD schedule has occurred across Ontario with limited systematic evaluation of potential health outcomes. The purpose of this study was to compare the food and nutrient value of grade 3 and 4 students’ packed lunch contents and consumption in the BSD versus TS, by direct observation. When compared to the TS, more BSD students had a sugar-sweetened beverage packed in their lunch. Greater portions of snack items were also …

Environmental Health Effects Of Multiple Exposures: Systemic Risks And The Detroit River International Crossing Study, Tor H. Oiamo

Electronic Thesis and Dissertation Repository

This thesis examines cumulative exposures to traffic noise and outdoor air pollution on environmental and health related quality of life in Windsor, Ontario, and provides a critical analysis of the environmental assessment process for the Detroit River International Crossing (DRIC) Study. The research utilizes a systemic risk framework to understand environmental health and stress effects of cumulative exposures. The significance of this research is based on a relative absence of literature on the systemic health risks of cumulative exposures and the need to elucidate environmental annoyance as a health outcome for risk assessment. The objectives of the research were to …

Exploring Pregnant Women’S Perceptions And Decision Making Of Household Chemicals: Phthalates As A Model, Justin M. Ashley

Electronic Thesis and Dissertation Repository

Recent research has identified a group of plasticizers known as phthalates as potential anti-androgens and a risk to developing male fetuses. A constructivist grounded theory study was used to understand pregnant women and obstetrical care providers’ perceptions of phthalates. Twenty-three pregnant women and twelve obstetrical care providers (Obstetricians, Family Physicians, and Midwives) from Southwestern Ontario participated in semi-structured interviews. Pregnant women and clinicians had little knowledge regarding phthalates and the potential associated risks. Women felt that knowledge of these risks would be important to prenatal counselling while clinicians required more evidence. Two separate but related models emerged from the data …