Author: Marianne Parent
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
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Book Description
Volatile organic compounds (VOC) research in the residential indoor environment has focused on respiratory conditions; additional research is necessary to understand the effects on overall health. I analyzed the Canadian Health Measures Survey (CHMS) data Cycle 2 for indoor air exposure in children (3-11 years old) and youth-adults (12-79 years old) as stratified the age and location of the dwelling. I performed multivariate linear regressions to describe the variations in log-transformed total BTEX, chloroform, naphthalene and alpha-pinene in separate analyses. I performed small laboratory studies to optimize the use of thermal desorption tubes during indoor air research. Total BTEX concentrations were associated with dwelling characteristics: type, age, number of residents and mortgage. The concentrations of naphthalene and alpha-pinene were significantly associated with the presence of a child in the dwelling. The analysis of CHMS Cycle 2 dataset and the descriptive studies allowed for new insights into VOC exposures.
Author: Srinandini Parthasarathy
Publisher:
ISBN:
Category :
Languages : en
Pages : 121
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Book Description
Humans spend most of their time indoors, in residences and commercial buildings. In this thesis, I evaluate exposures to volatile (VOCs) and semivolatile organic compounds (SVOCs) in indoor environments. I use a combination of literature review and evaluation, mechanistic modeling, and skin-wipe collection and analysis to develop an understanding of the role of indoor air as an exposure medium for inhalation and passive dermal uptake of pollutants. This dissertation explores three related research topics on indoor environments and human exposures. In Chapter 2, I conduct a comprehensive review of reported measurements of pollutants found in commercial buildings. I used the literature review to estimate concentration ranges that can be compared to health-based exposure limits as basis for hazard assessment. I use the regulatory exposure limits set by government agencies to calculate hazard indices as the ratio of observed concentrations to regulatory standards. I also compare the odor and pungency thresholds of individual pollutants to observed concentrations to evaluate their potential to exceed odor thresholds. The hazard evaluation identifies the potential for health impacts at concentrations commonly found in commercial buildings. This analysis focuses exclusively on VOCs and SVOCs in commercial buildings and identified a limited set of pollutants that pose health concerns. I also characterize the selected pollutants in terms of the chemical properties that,affect partitioning to various indoor surfaces, and subsequently their fate and transport in indoor environments. Based on chemical properties and indoor fate, I grouped the pollutants into five groups. I use an hierarchical k-means analysis based on octanol-air partitioning coefficient, octanol-water partitioning coefficient, air-water partitioning coefficient, and molecular weight. The pollutants in each group are expected to behave similarly in indoor environments. In Chapter 3, I evaluate the role of buildings operation parameters such as ventilation and filtration in limiting exposures to pollutants originating from indoor and outdoor sources. I use a simple well-mixed-air model of an indoor space to study the impact of ventilation on concentrations of ozone, nitrogen dioxide, carbon monoxide, and radon. I employ a chemical-thermodynamics-(fugacity)-based mass balance model in conjunction with a particle mass balance to study the fate and transport of particulate matter, VOCs, and SVOCs. The fugacity mass balance model accounts for chemical partitioning among air, air-borne particles, and indoor surfaces. I ran the fugacity model with indoor and outdoor source of VOCs and SVOCs and indoor and outdoor sources of particulate matter. I evaluate the consequent inhalation exposures these sources with two outcome metrics, intake fraction (iF) for indoor sources and indoor/outdoor concentration ratio for outdoor sources. The exposure to particulate matter of indoor and outdoor origin was evaluated using the outcome metrics iF and the indoor proportion of outdoor particles (iPOP). The model evaluation shows that ventilation is most effective at controlling exposures to VOCs that have an indoor source. Filtration is seen to be effective at controlling exposures to particulate matter and SVOCs that partition preferentially onto particulate matter. In Chapter 4, I explore the role of indoor air in delivering SVOCs to human occupants through passive dermal uptake. I collected wipe samples from thirteen subjects who were randomly chosen. For each subject, I collected three sequential wipe samples from the forehead and one sample from the palm. I analyzed the samples for a suite of SVOCs and skin lipids (squalene and sapienic acid) in an analytical laboratory using gas chromatography and liquid chromatography. All forehead wipe samples contained SVOCs indicating that air to skin transfer of pollutants for passive dermal uptake could be a significant exposure pathway for SVOCs. Because skin lipid concentrations decrease with depth the quantitation of skin lipid concentrations from each wipe allowed me to estimate the depth of sampling by each skin wipe. This is the first study to quantitatively evaluate the depth of sampling by skin wipes. I use the experimental results together with a theoretical model to explore the potential role of skin as a passive sampler for short-term personal exposures, indoors. For this I develop a metric called the equivalent time of exposure (ETE) to study the usefulness of sequential skin wipe samples as a passive sampler. I used partitioning coefficients from air to skin surface, combined with a dynamic skin mass transport model, to study the theoretical transport of pollutant through the stratum corneum. I compare the modeled concentrations to measured concentrations, at comparable depths. The ETE is the amount of time to which the subject would have to be exposed to a constant air concentration to attain the observed skin-wipe concentration depth profile in the stratum corneum. Based on the ETE, I find that skin wipe samples could be indicative of exposures up to 6 hours prior to wipe sampling, depending on the diffusion coefficient of the pollutant. The overarching goal of this research is to evaluate the role of indoor air in mediating the transfer to human receptors of pollutants released indoors or brought indoors from outdoor sources. The indoor air mass controls the fate and transport of pollutants in indoor spaces, and the rate of delivery of pollutants for inhalation and dermal uptake. The research highlights the important role of air-to-surface and air-to-particle partitioning in facilitating or mitigating source-receptor relationships. The work illustrates future research opportunities for tracking the complex web of indoor/outdoor pathways that bring pollutants into the human environment and into the blood and other viable tissues of the human population.
Author: Institute of Medicine
Publisher: National Academies Press
ISBN: 0309209412
Category : Science
Languages : en
Pages : 286
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Book Description
The indoor environment affects occupants' health and comfort. Poor environmental conditions and indoor contaminants are estimated to cost the U.S. economy tens of billions of dollars a year in exacerbation of illnesses like asthma, allergic symptoms, and subsequent lost productivity. Climate change has the potential to affect the indoor environment because conditions inside buildings are influenced by conditions outside them. Climate Change, the Indoor Environment, and Health addresses the impacts that climate change may have on the indoor environment and the resulting health effects. It finds that steps taken to mitigate climate change may cause or exacerbate harmful indoor environmental conditions. The book discusses the role the Environmental Protection Agency (EPA) should take in informing the public, health professionals, and those in the building industry about potential risks and what can be done to address them. The study also recommends that building codes account for climate change projections; that federal agencies join to develop or refine protocols and testing standards for evaluating emissions from materials, furnishings, and appliances used in buildings; and that building weatherization efforts include consideration of health effects. Climate Change, the Indoor Environment, and Health is written primarily for the EPA and other federal agencies, organizations, and researchers with interests in public health; the environment; building design, construction, and operation; and climate issues.
Author:
Publisher:
ISBN:
Category : Air quality
Languages : en
Pages : 40
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Book Description
Author: Tunga Salthammer
Publisher: John Wiley & Sons
ISBN: 3527628894
Category : Science
Languages : en
Pages : 464
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Book Description
With the quality of indoor air ranking highly in our lives, this second, completely, revised edition now includes 12 completely new chapters addressing both chemical and analytical aspects of organic pollutants. Sources of indoor air pollutants, measurement and detection as well as evaluation are covered filling the gap in the literature caused by this topical subject. This book is divided into four clearly defined parts: measuring organic indoor pollutants, investigation concepts and quality guidelines, field studies, and emission studies. The authors cover physico-chemical fundamentals of organic pollutants, relevant definitions and terminology, emission sources, sampling techniques and instrumentation, exposure assessment as well as methods for control. Test methods and studies for various indoor environments are described, such as automobile interiors, museum environments, or rooms with air ventilation. Emission sources covered include household and consumer products as well as electronic devices and office equipment. The book is aimed at chemists, physicists, biologists, and medical doctors at universities and research facilities, in industry and environmental laboratories as well as regulative bodies.
Author:
Publisher:
ISBN:
Category : Air
Languages : en
Pages : 68
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Author: Javier Alfonso Garrido
Publisher:
ISBN: 9780438290259
Category :
Languages : en
Pages :
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Book Description
Semi-volatile organic compounds (SVOCs) are ubiquitous in the indoor environment and a priority for exposure assessment because of the environmental health concerns that they pose. Direct air-to-skin dermal uptake has been shown to be relevant and comparable to the inhalation fraction for compounds with certain chemical properties. In this study, we aim to further understand the transport of these type of chemicals through the skin, specifically through the stratum corneum (SC), and we do so by collecting three subsequent forehead skin wipes, each removing pollutants deeper from the skin layers, and using this wipe analysis to determine the skin concentration profiles. The removal of SVOCs with repeated wipes reveals the concentration profiles with depth and provides a way to characterize penetration efficiency and potential to be absorbed into the bloodstream. Concentration profiles of SVOCs were simulated using a diffusive model in the skin and compared with the measured values. We found that two phthalates, dimethyl and diethyl phthalates, penetrate deeper in the skin with similar times of exposure, as compared to other phthalates and targeted SVOCs, an observation supported by the model results as well. We also report the presence of statistically significant declining patterns with skin depth for most SVOCs, indicating that their diffusion through the SC is relevant and eventually can reach the blood vessels in the vascularized dermis. Finally, different oxidationproducts, linked to respiratory irritation symptoms, formed from the reaction between ozone and squalene, were identified in the skin by a non-target approach.
Author: John D. Spengler
Publisher: McGraw Hill Professional
ISBN: 0071414843
Category : Technology & Engineering
Languages : en
Pages : 1675
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Book Description
* Tackles the complex environmental issue of Indoor Air Quality (IAQ) for industrial hygienists, HVAC engineers, architects and anyone else concerned with the air quality of interiors * Infused with charts, tables, and all the major formulas and calculations necessary to monitor and characterize a particular environment * Includes all relevant codes, standards and guidelines
Author:
Publisher: National Academies
ISBN:
Category : Science
Languages : en
Pages : 404
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Book Description
Author: National Research Council
Publisher: National Academies Press
ISBN: 0309264685
Category : Nature
Languages : en
Pages : 210
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Book Description
From the use of personal products to our consumption of food, water, and air, people are exposed to a wide array of agents each day-many with the potential to affect health. Exposure Science in the 21st Century: A Vision and A Strategy investigates the contact of humans or other organisms with those agents (that is, chemical, physical, and biologic stressors) and their fate in living systems. The concept of exposure science has been instrumental in helping us understand how stressors affect human and ecosystem health, and in efforts to prevent or reduce contact with harmful stressors. In this way exposure science has played an integral role in many areas of environmental health, and can help meet growing needs in environmental regulation, urban and ecosystem planning, and disaster management. Exposure Science in the 21st Century: A Vision and A Strategy explains that there are increasing demands for exposure science information, for example to meet needs for data on the thousands of chemicals introduced into the market each year, and to better understand the health effects of prolonged low-level exposure to stressors. Recent advances in tools and technologies-including sensor systems, analytic methods, molecular technologies, computational tools, and bioinformatics-have provided the potential for more accurate and comprehensive exposure science data than ever before. This report also provides a roadmap to take advantage of the technologic innovations and strategic collaborations to move exposure science into the future.
