Download or read book Understanding Exposures to Volatile and Semivolatile Organic Compounds in Indoor Environments written by Srinandini Parthasarathy and published by . This book was released on 2016 with total page 121 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Assessment of Exposure to Indoor Air Pollutants written by Matti Jantunen and published by WHO Regional Office Europe. This book was released on 1997 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt: Most people spend most of their time indoors, and the poor quality of the indoor environment is a strong determinant of a variety of health problems. The principal way of preventing adverse health effects is to eliminate exposure to hazardous factors. But first, standardized methods of assessing exposure are necessary to assess the risk to health and to select optimal risk management actions. This book aims to facilitate the implementation of exposure assessment methods in public health practice.

Download or read book Toward an Understanding of Children s Exposure to Semi volatile Organic Compounds in the Indoor Environment written by Elizabeth Lydia Cooper and published by . This book was released on 2012 with total page 59 pages. Available in PDF, EPUB and Kindle. Book excerpt: The prevalence of smoking has declined significantly from the middle of the last century in most developed nations. Since the mid-1990s however, the rates of decline have slowed and prevalence of smoking among young women is projected to rise in some countries (World Health Organization, 2011; Centers for Disease Control and Prevention, 2011). Most U.S. states and many countries have restricted the smoking of cigarettes in public places, which has made the home the major site for exposure for non-smokers. These patterns of tobacco use place more infants and children at risk for involuntary exposure to tobacco smoke. While many smokers recognize the potential harm of secondhand smoke, and change their behavior to mitigate direct exposure to people around them, the extent to which constituents of tobacco smoke, termed thirdhand smoke (THS), persist in the indoor environment and contribute to exposure is poorly understood by the public (Winickoff et al., 2009). Rehan et al. (2011) described THS as a "stealth toxin" due to its presence in places and on surfaces that are used by unsuspecting and vulnerable populations, and because most people, both smokers and non-smokers do not recognize any danger associated with THS.

Download or read book Indoor Air Quality written by Hermann Fromme and published by Springer Nature. This book was released on 2023-11-29 with total page 587 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents a comprehensive and detailed overview of indoor pollution, covering the main contaminants in the indoor environment – air and dust, the health aspects of exposure, and different possibilities for a risk assessment. The book outlines the chemical substances and physical and biological factors that occur more frequently indoors, which are of health significance, or for which only limited information on their occurrence indoors is available to date. It also provides guidance to identify where problems may arise in the future and where data is missing for a valid exposure and risk assessment as well as for consequent risk management. Written by a highly recognized and experienced medical expert in the field, the book starts with an introduction to the indoor environment, including topics such as indoor environmental quality and health, indoor climate, sampling of indoor pollutants, and measures to improve indoor air quality. The author then delves into the fundamentals of exposure assessment and special exposure indoor situations, followed by in-depth coverage of the health aspects, and indoor air occurrence of several substances such as volatile organic compounds, very volatile organic compounds, semi-volatile organic compounds, and particulate matters and fibers. Particular attention is given to bioaerosols like mold, microbial volatile organic compounds, mycotoxins, and viruses. Readers will also find chapters devoted to the main health aspects and indoor occurrence of inorganic gases, radon and metals, and smoking. The book closes with a chapter on risk assessment, in which readers will learn more about the basics of risk assessment, key points and processes of a health evaluation, and guidance for assessing indoor air contamination. This book is a unique compilation of the current worldwide exposure situation in private and public indoor spaces, and an important reference for researchers that are willing to assess the rising burden of disease and potential causes behind degraded indoor air quality. Scientists, students, and policymakers interested in the fields of medicine and environmental sciences will understand the appeal of this book.

Download or read book Exposure Assessment for Air to skin Uptake of Semi volatile Organic Compounds SVOCs Indoors written by Javier Alfonso Garrido and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Environmental Health written by Theodore A. Myatt and published by CRC Press. This book was released on 2016-04-19 with total page 241 pages. Available in PDF, EPUB and Kindle. Book excerpt: This title includes a number of Open Access chapters.Recent advances have been made on the identification of pollutants in indoor environments, the health effects associated with indoor or personal exposures, and interventions that can be implemented by occupants to mitigate exposures. The focus of this book is on exposures that occur typically, bu

Download or read book Indoor Air Research written by and published by . This book was released on 1994 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Variability and Temporal Trends of Semivolatile Organic Compounds in Biological and Environmental Media written by Kyunghoon Kim and published by . This book was released on 2022 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt: Exposure to semivolatile organic compounds (SVOCs) in indoor environments and its potential impact on human health have been receiving increased public attention, because people in developed countries spend over 80% of their time indoors, SVOC levels are several orders of magnitude higher indoors than outdoors, and many SVOCs have various toxicities and endocrine disrupting potential. Concentrations of SVOCs in biological (e.g., human serum) and environmental (e.g., household dust, indoor air) media can help us better understand human exposure to SVOCs. For example, SVOC concentrations in biological media collected over several years may shed light on temporal trends of exposure due to the changes in consumer use or regulations. In addition, SVOC concentrations in indoor dust repeatedly collected in the same home may allow us to examine temporal variability of exposure via non-dietary dust ingestion. Lastly, SVOC concentrations in upholstered home furniture with frequent skin contact may improve our understanding of exposure via direct skin contact with furniture surfaces, particularly for infants and young children. My dissertation studies include three sub-studies: (1) examining temporal trends and determinants of concentrations of SVOCs in blood serum samples, (2) examining temporal variability of dust concentrations and factors affecting dust concentrations for SVOCs, and (3)evaluating couch polyurethane foam (PUF) for a potential passive sampler of SVOCs. In the first study, I utilized measured concentrations of per- and polyfluoroalkyl substances (PFAS), one class of SVOCs, in serum collected from California mothers with a young child. Then, I used multiple regression to estimate geometric means of PFAS concentrations for each sampling year (2009-2016), with adjustment for sampling year and other population characteristics that may affect PFAS concentrations in maternal serum. I observed that perfluorooctanoate (PFOA), perfluorooctane sulfonate (PFOS), and perfluorohexane sulfonate (PFHxS) decreased over the study period, consistent with results of some studies reported for other U.S. populations and other studies outside the USA. My study showed that body burden of some common long-chain PFAS decreased over the study period among California mothers with a young child.In the second study, I utilized measured concentrations of a wide range of SVOCs in dust collected three times from the same home during a period of 22 months. To test for within-home temporal variability of SVOC concentrations in household dust, I computed intraclass correlation coefficients (ICCs), a ratio of between-home variance to total variance (within-home variance +between-home variance). Among 26 compounds that were detected in more than 50% of the samples at all three visits, 20 compounds had ICCs above 0.50 and 6 compounds had ICCs below 0.50. For 19 out of 26 compounds, correlation coefficients between spring and fall (r =0.48-0.98) were higher than those between summer and winter (r = 0.09-0.92), implying seasonal effects on dust concentrations. My study showed that within-home temporal variability of dust concentrations was small (ICC > 0.50) for most SVOCs, but dust concentrations may vary overtime for some SVOCs with seasonal variations in source rates, such as product use.In the third study, I utilized measured concentrations of non-flame retardant SVOCs in couch PUF at three different depths. Then, I examined concentration changes with depths and developed predictive equations for the PUF-air partition coefficient (KPUF-air). Among 29 detected compounds, 11 compounds were detected in more than 50% of the samples at all depths. Among the 11 compounds, concentrations of phenanthrene, 2-benzylideneoctanal, galaxolide, tonalide, and homosalate decreased with depth. Among the studied SVOCs, calculated log KPUF-air values varied from 2.46 (dimethyl phthalate) to 7.80 (homosalate), and Koa(r2 = 0.62) was a stronger predictor of KPUF-air than VP (r2 = 0.47). My study showed that couch PUF can absorb many SVOCs but may not be an effective passive sampling medium for those that were less frequently detected in couch PUF and had low correlation coefficients between concentrations in dust and PUF.

Download or read book A Modeling Approach for Quantifying Exposures from Emissions of Spray Polyurethane Foam Insulation in Indoor Environments written by Charles Bevington and published by . This book was released on 2017 with total page 29 pages. Available in PDF, EPUB and Kindle. Book excerpt: A range of chemicals from very volatile to semivolatile organic compounds are emitted from spray polyurethane foam (SPF) insulation. SPF installation procedures and environments can vary widely, and the emissions, transport, and fate of these chemicals in the indoor environment after SPF installation are not well characterized. To begin to understand exposure to emissions from SPF and to identify and characterize the uncertainty in assessing chemical exposures, a proof-of-concept multizone indoor model was developed to estimate indoor air concentrations of chemicals emitted from SPF over time. The model supported the development of different approaches for characterizing the emissions of volatile and semivolatile organic compounds and for predicting short- and long-term emissions and subsequent air concentrations. It also incorporated estimates for a wide range of parameters that influence emission and subsequent exposure from SPF. A sensitivity analysis was performed to explore the impact of model inputs, including those considered the most influential and those for which there is uncertainty because of a lack of data. Model inputs included the location and type of SPF foam; the chemical-specific diffusion and partitioning coefficients; the temperature and ventilation rates of zones within the residence; and the impact of engineering controls, such as increased ventilation during installation. Sensitivity analysis results identified trends and relations between model inputs and outputs. Additional experimental data are needed to calibrate the model and to reduce uncertainty of model estimates. In particular, information is needed to characterize emissions within the first 24 h after spray application, to characterize longer-term mass transfer of chemicals from SPF, and to describe interzonal air flow and leakage rates between attics, living spaces, and crawl spaces.

Download or read book Dynamic Behavior of Semivolatile Organic Compounds in Indoor Air written by Michael David Van Loy and published by . This book was released on 1998 with total page 520 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Handbook of Indoor Air Quality written by Yinping Zhang and published by Springer Nature. This book was released on 2022-11-23 with total page 2182 pages. Available in PDF, EPUB and Kindle. Book excerpt: People live in indoor environment about 90% of lifetime and an adult inhales about 15 kg air each day, over 75% of the human body’s daily mass intake (air, food, water). Therefore, indoor air quality (IAQ) is very important to human health. This book provides the basic knowledge of IAQ and highlights the research achievements in the past two decades. It covers the following 12 sections: introduction, indoor air chemicals, indoor air particles, measurement and evaluation, source/sink characteristics, indoor chemistry, human exposure to indoor pollutants, health effects and health risk assessment, IAQ and cognitive performance, standards and guidelines, IAQ control, and air quality in various indoor environments. It provides a combination of an introduction to various aspects on IAQ studies, the current state-of-knowledge, various advances and the perspective of IAQ studies. It will be very helpful for the researchers and technicians in the IAQ and the related fields. It is also useful for experts in other fields and general readers who want to obtain a basic understanding of and research advances in the field of IAQ. A group of experts in IAQ research have been recruited to write the chapters. Their research interests and experience cover the scope of the book. In addition, some experienced experts in IAQ field have been invited as advisors or reviewers to give their comments, suggestions and revisions on the handbook framework and the chapter details. Their contribution guarantees the quality of the book. We are very grateful to them. Last but not least, we express our heartfelt thanks to Prof. Spengler, Harvard University, for writing the foreword of the current Handbook of Indoor Air Quality both as a pioneer scientist who contributed greatly to indoor air science and as an Editor-in-chief of Handbook of Indoor Air Quality 2001, 1st ed. New York: McGraw-Hill. In addition to hard copies, the book is also published online and will be updated by the authors as needed to keep it aligned with current knowledge. These salient features can make the handbook fresh with the research development.

Download or read book Impacts of Household Characteristics Activities and Building Characteristics on Indoor Concentrations of Semi volatile Organic Compounds written by Yuchao Wan and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: When compared to outdoors, the indoor environment often has higher concentrations of some SVOCs, such as brominated flame retardants (BFRs), organophosphate esters (OPEs) and phthalates that are used as additive flame retardants and plasticizers from consumer products and building materials. Some outdoor SVOCs, such as polycyclic aromatic hydrocarbons (PAHs), can be transported into indoor environments, increasing indoor exposures to these compounds. With the increasing concerns about the implications of exposure for human health, attention has turned towards concentrations of SVOCs in indoor environments, particularly in residential dwellings where North Americans spend more than 60% of their time. This thesis documented concentrations of these SVOCs in residential buildings, focussed on the exposure disparities in SVOCs according to socio-economic status (SES), and developed SVOC sampling methods in low-SES homes. Quantitative filter forensics (QFF) was extended to portable air cleaners with portable filters to quantitatively estimate indoor particle-bound SVOCs, overcoming the limitations of traditional QFF requiring forced-air heating, ventilation and air conditioning (HVAC) systems, while also improving indoor air quality by removing particular matter (PM). This thesis also advanced knowledge on the impacts of household characteristics, activities and building characteristics on indoor SVOC concentrations. The research found SVOC exposure disparities according to SES in Canada, reinforcing the importance of better understanding of the intersection between contaminant exposure, housing quality, household characteristics, and activities that can elevate SVOC levels, and SES, with the aim of reducing exposures from residences in an equitable manner.

Download or read book Indoor Air and Human Health written by Richard B. Gammage and published by CRC Press. This book was released on 2018-04-13 with total page 444 pages. Available in PDF, EPUB and Kindle. Book excerpt: PART FIVE: ORGANICS -- 25. Part Five: Overview -- 26. Review of Analytical Methods for Volatile Organic Compounds in the Indoor Environment -- 27. Sampling and Analysis Methodology for Semivolatile and Nonvolatile Organic Compounds in Air -- 28. Organic Chemicals in Indoor Air: A Review of Human Exposure Studies and Indoor Air Quality Studies -- 29. Does Formaldehyde Cause Allergic Respiratory Disease? -- 30. Volatile Organic Compounds in Indoor Air: An Overview of Sources, Concentrations, and Health Effects -- 31. Volatile Organic Compounds as Indoor Air Pollutants -- 32. Summary and Conclusions -- Index

Download or read book An EXPOSURE ASSESSMENT STUDY OF VOLATILE ORGANIC COMPOUNDS VOCS IN RESIDENTIAL INDOOR ENVIRONMENT USING THE CANADIAN HEALTH MEASURES SURVEY CYCLE 2 written by Marianne Parent and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Semi Volatile Organic Compounds and Flame Retardants written by and published by . This book was released on 2009 with total page 66 pages. Available in PDF, EPUB and Kindle. Book excerpt: "SVOCs [semi volatile organic compounds] included in the review are plasticisers, like phthalates, flame retardants (FRs), like brominated organic compounds and organophosphate esters. In addition, polyaromatic hydrocarbons (PAHs), which are constituents in coal tar/creosote and have been used for moisture proofing in structures, are also discussed. On the basis of present knowledge, risk assessment for exposure indoors is presented. In addition, sources of SVOCs and the waste potential in the old building stock are also clarified." p. 3.

Download or read book Dynamic Behavior of Semivolatile Organic Compounds in Indoor Air written by and published by . This book was released on 1998 with total page 262 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Modeling of Indoor Air Quality and Exposure written by Niren Laxmichand Nagda and published by ASTM International. This book was released on 1993 with total page 302 pages. Available in PDF, EPUB and Kindle. Book excerpt: