Karen Hastings Bartlett

Interior living walls are promoted partly due to their ability to improve indoor air quality, and possibly reduce energy consumption related to ventilation. However, the studies done to demonstrate this ability are largely conducted in conditions that differs from those of building environments, and they have only focused on a single factor that impacts indoor air quality. This study examined several factors that living walls can affect indoor air quality (volatile organic compounds, carbon dioxide, relative humidity, and bioaerosols) and evaluated how each of these may improve or reduce indoor air quality.A test chamber was designed to simulate building environment conditions, including temperature, lighting, and ventilation. Three volatile organic compounds and CO₂ were added into the test chamber to simulate occupancy. Samples were taken in the test chamber with and without a living wall to determine differences due to the presence of a living wall.The interior living wall removed CO₂ and one of the three volatile organic compounds in the test chamber, increased relative humidity, and promoted the increased presence of bioaerosols. While living walls may improve some aspect of indoor air quality, considerations must be taken to mitigate the other impacts on indoor air quality.

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Introduction:Healthcare-associated infections are a significant public health burden, which affect thousands of Canadians and cost millions of dollars, annually. Flushing toilets can generate pathogen-containing droplets and aerosols, and are a unique challenge in controlling pathogen transmission in healthcare facilities and other settings. This research assessed microbial dissemination of a) bacteria and b) virus from a flushing toilet in a patient area at Vancouver General Hospital. This project also c) evaluated the effectiveness of a permanently installed, automated ultraviolet C (UVC) device for reducing bacterial concentrations in air and on two surfaces in a shared patient bathroom at Lions Gate Hospital.Methods:a) Gram negative Escherichia coli and Gram positive Enterococcus faecalis, were used to simulate human stool during flushing events and viable air samples were collected with the Duo Surface Air System 360 sampler at multiple locations and time points post-flushing. b) A norovirus surrogate, MS2 bacteriophage, was also used to assess potential aerosolization of norovirus during flushing. c) Airborne and surface bacterial concentrations were compared in a bathroom with UVC and a comparable control bathroom.Results:a) Gram negative E. coli concentrations exceeded E. faecalis immediately post-flush at the location closest to the source, but decreased rapidly at successive time points and further sampling locations. In contrast, the Gram positive E. faecalis persisted significantly longer, and sampling location had no effect on its concentrations.b) Airborne phage was detected at concentrations far above the infectious dose for norovirus of 18 virions, and infectious phage particles were still present up to 60-minutes post-flushing.c) Airborne and surface bacterial concentrations were significantly reduced in the bathroom with UVC, compared to a comparable control bathroom.Conclusion:This work was the first study to evaluate both a Gram negative and Gram positive organism in the toilet plume, and show significantly longer persistence of the Gram positive bacteria. This research also showed that flushing toilets may generate airborne norovirus at concentrations capable of causing infection. Lastly, this work showed that optimized UVC is an effective adjunct to manual cleaning and infection control efforts in bathrooms.

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Aspects of the indoor environment that directly influence the occupants are ventilation, indoor-air quality (IAQ), acoustic and thermal condi¬tions, as well as lighting. All five aspects were studied to investigate the indoor environmental quality (IEQ) in a sustainable building (CIRS) at the University of British Columbia, Vancouver campus. Physical measurements were made in several selected spaces (mainly offices and meeting rooms) to monitor indoor parameters such as background noise level, reverberation time, VOC and CO₂ concentrations, ambient temperature, relative humidity, indoor illuminance level, etc. Building performance was analyzed by comparing the measurement results to standard criteria, and to the design goals of CIRS. Several selected spaces in CIRS were found unsatisfactory in some aspects of IEQ – e.g. the mechanical ventilation system was unable to remove 80% of outdoor ultrafine particles; more than 20% of the measured spaces exceeded the maximum recommended background noise level; 100% of the noise isolations between offices and their surroundings were inadequate; speech privacy between adjacent private offices was poor; rooms in the South wing suffered from very high illuminance levels, etc. Building features and management details that influenced IEQ were discussed to analyze the relationships between building design/operation and performance. Several room features were discussed, such as air change rate, furnishing material, ventilation types, acoustical characteristics, etc. Several conclusions were drawn – e.g. ventilation conditions of rooms were highly affected by the door/windows statuses; rooms with the lowest air change rates had the highest UFP concentrations; crowd noises in the atrium caused high background noise levels; inadequate noise isolations were caused by indoor light-weight partitions, etc.

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For the purposes of this study, a community garden was defined as an urban space that is divided into plots and assigned to individuals or households, who share in communal responsibilities and decision-making.A literature review found that little research exists regarding community gardening, particularly in relation to policy but also to some aspects of health. There were also similarities in the research between community gardening, gardening in general, and social and therapeutic horticulture (STH). The aims of this study were to explore the motivations, experiences and practices of community gardeners and garden coordinators within the City of Vancouver, and become familiar with key characteristics of community gardens; to investigate any health effects perceived in relation to community gardening; and to examine the role of policy in shaping community gardening in Metro Vancouver and other municipalities.Using a listing of community gardens provided by the City of Vancouver, garden coordinators were contacted and requested to participate in the study by completing a brief survey on phone or electronically, and by forwarding a request for participation to their gardeners. Besides email, gardeners were also recruited at garden events, and were thereafter interviewed on phone for approximately an hour. For emotional and social well-being, as well as nutrition, community gardening was perceived to be highly beneficial. For mental abilities, physical fitness and financial status it was found to have little to no substantial benefit or harm, given that, for the latter two, most community gardeners were regularly involved in more rigorous physical activity, and were also socioeconomically secure. Most gardeners were also less than 50 years of age, female, Caucasian, highly educated and high income earners, and most gardens were located in middle income neighborhoods, with an average of 64 plots, a mean area of half a city block, and a mean age of 10 years. Most Metro Vancouver municipalities had at least one community garden, but no policies in place that were exclusive to community gardening.

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Cryptococcus gattii is a human fungal pathogen that emerged on Vancouver Island, BC in 1999. This study aimed to investigate C. gattii survival in composting systems and occupational exposure to C. gattii in work tasks associated with composting. The presence of C. gattii was monitored in composting feedstock and product for one calendar year in a municipal composting facility in Cumberland, BC. Additionally, the survival of an environmental C. gattii isolate was tested in a composting experiment conducted with custom-designed composters that simulated in-vessel composting and home backyard composting. Potential inhalation occupational exposure to C. gattii while performing composting-related tasks were measured during residential yard waste chipping by city workers in Parksville, BC and during the composting experiment where C. gattii contaminated feedstock was composted. C. gattii persisted through three out of five in-vessel composting trials despite high composting temperatures (mean > 60ºC, peak 85ºC) which were achieved evenly throughout the composting material for long periods (> 65 hours). C. gattii was also detected in one out of two yard composting trials after 60 days of composting. The year-long composting feedstock and compost monitoring for C. gattii returned no positive samples. Air sampling during composting-related work tasks found no detectable level of C. gattii. Current composting standard and practice in BC are unlikely to be adequate in eliminating C. gattii from contaminated composting feedstock. Based on the results of this study, the risks of occupational exposure to C. gattii during residential yard waste chipping and composting of contaminated material are low.

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