Download or read book Assessment of Personal Exposure to Air Pollution Based on Trajectory Data written by Guixing Wei and published by . This book was released on 2018 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt: Air pollution has been among the biggest environmental risks to human health. Exposure assessment to air pollution is essentially a procedure to quantify the degree to which people get exposed to hazardous air pollution. Exposure assessment is also a critical step in health-related studies exploring the relationship between personal exposure to environmental stressors and adverse health outcomes. Given the critical role of exposure assessment, it is important to accurately quantify and characterize personal exposure in geographic space and time. For years numerous exposure assessment methods have been developed with respect to a wide spectrum of air pollutants. Of all the methods, the most commonly used one is to use a representative geographic unit as the surrogate location to estimate the potential impact from hazardous air pollution from differing sources on that location. The representative unit is one person's home location in most cases. Such studies, however, have failed to recognize the significance of both the dynamics of human activities and the variation of air pollution in geographic space and time. It is believed that personal exposure is essentially a function of space and time as an individual's time-activity patterns and intensities of air pollutant in question vary over space and time. It is therefore imperative to account for the spatiotemporal dynamics of both in exposure assessment. To this end, the goal of this study is to account for the spatiotemporal dynamics of both human time-activity patterns and air pollution for assessing personal exposure. More specifically this dissertation aims to achieve three objectives as summarized below. First, in light of the deficiency of existing home-based exposure assessment methods, this study proposes an innovative trajectory-based model for assessing personal exposure to ambient air pollution. This model provides a computational framework for assessing personal exposure when trajectories, documenting human spatiotemporal activities, are modeled into a series of tours, microenvironments (MEs), and visits. A set of individual-level trajectories was simulated to test the performance of the proposed model, in conjunction with one-day air pollution (PM2.5) data in Beijing, China. The results from the test demonstrated that the trajectory-based model is capable of capturing the spatiotemporal variation of personal exposure, thus providing more accurate, detailed and enriched information to better understand personal exposure. The findings indicate that there is considerable variation in intra-microenvironment and inter-microenvironment exposure, which identified the importance of distinguishing between different MEs. Moreover, this study tested the proposed model using an empirical dataset. Second, little is known about the difference between the estimated exposure based on home locations only and that considering the locations of all human activities. To fill this gap, this study aims to test whether the exposure calculated from the home-based method is statistically significantly different from the exposure estimated by the newly developed trajectory-based model. A Dataset containing 4,000 individual-level one-day trajectories (Dataset 1) was simulated to test the aforementioned hypothesis. The exposure estimates in comparison are the average hourly exposure over a 24-hour period from two exposure assessment methods. The 4,000 trajectories were split into another two subsets (Datasets 2, 3) according to the difference between home-based exposure estimates and trajectory-based exposure estimates. The Wilcoxon Signed-rank test was used to evaluate whether the difference between the two models is significant. The results show that the statistically significant difference was found only in Dataset 3. The same test was also applied to a set of empirical trajectories. The significant difference exists in the results from the empirical data. The mixed results suggest that additional research is needed to verify the difference between the two exposure assessment methods. Third, little research has taken into consideration of hourly traffic variation and human activities simultaneously in a model for assessing personal exposure to traffic emissions. To fill this gap, this study develops a new trajectory-based model to quantify personal exposure to traffic emissions. The hourly share of daily traffic volume of each roadway in the study area was estimated by calculating the traffic allocation factors (TAFs) of each roadway. Next, the hourly traffic emission surfaces were built using the hourly shares and a kernel density algorithm. A 3-D cube representing the spatiotemporal distribution of traffic emission was constructed, which overlaid the simulated individual-level trajectory data for assessing personal exposure to traffic emissions. The results showed that people's time-activity patterns (e.g., where an individual lives/works, where an individual travels) were significant factors in exposure assessment. This study suggests that people's time activities and hourly variation of traffic emission should be simultaneously addressed when assessing personal exposure to traffic emissions. To sum up, this study has devoted a large effort in quantifying and characterizing personal exposure in geographic space and time. A few of contributions to the knowledge of exposure science are listed as follows. First, this study contributes two exposure assessment models in characterizing personal spatiotemporal exposure using trajectory data. One is developed for assessing personal exposure to ambient air pollution, and the other one is for assessing personal exposure to traffic emissions. Second, this study demonstrates the intra- and inter-microenvironment variation of personal exposure and reveals the significance of people's time-activity patterns in exposure assessment. Third, this study investigates the difference in exposure estimates between conventional home-based methods considering home locations only and trajectory-based methods accounting for the locations of all activities. The mixed findings from Wilcoxon Signed-rank tests suggest more research is needed to explore how personal exposure varies with time-activity patterns. All these contributions will have important implications in exposure science, environment science, and epidemiology.

Download or read book Human Exposure Assessment for Airborne Pollutants written by National Research Council and published by National Academies Press. This book was released on 1991-02-01 with total page 338 pages. Available in PDF, EPUB and Kindle. Book excerpt: Most people in the United States spend far more time indoors than outdoors. Yet, many air pollution regulations and risk assessments focus on outdoor air. These often overlook contact with harmful contaminants that may be at their most dangerous concentrations indoors. A new book from the National Research Council explores the need for strategies to address indoor and outdoor exposures and examines the methods and tools available for finding out where and when significant exposures occur. The volume includes: A conceptual framework and common terminology that investigators from different disciplines can use to make more accurate assessments of human exposure to airborne contaminants. An update of important developments in assessing exposure to airborne contaminants: ambient air sampling and physical chemical measurements, biological markers, questionnaires, time-activity diaries, and modeling. A series of examples of how exposure assessments have been applied-properly and improperly-to public health issues and how the committee's suggested framework can be brought into practice. This volume will provide important insights to improve risk assessment, risk management, pollution control, and regulatory programs.

Download or read book Development and Application of Individual and Population level Human Exposure Models for Fine Particles and Other Vehicle related Air Pollutants in Southern California written by Jun Wu and published by . This book was released on 2004 with total page 396 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Assessment of Individual level Exposure to Air Pollutants Using Personal Monitoring written by Rok Novak (ekotehnolog.) and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Exposure Information in Environmental Health Research written by and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Understanding and quantifying outdoor and indoor sources of human exposure are essential but often not adequately addressed in health-effects studies for air pollution. Air pollution epidemiology, risk assessment, health tracking and accountability assessments are examples of health-effects studies that require but often lack adequate exposure information. Recent advances in exposure modeling along with better information on time-activity and exposure factors data provide us with unique opportunities to improve the assignment of exposures for both future and ongoing studies linking air pollution to health impacts. In September 2006, scientists from the US Environmental Protection Agency (EPA) and the Centers for Disease Control and Prevention (CDC) along with scientists from the academic community and state health departments convened a symposium on air pollution exposure and health in order to identify, evaluate, and improve current approaches for linking air pollution exposures to disease. This manuscript presents the key issues, challenges and recommendations identified by the exposure working group, who used cases studies of particulate matter, ozone, and toxic air pollutant exposure to evaluate health-effects for air pollution. One of the over-arching lessons of this workshop is that obtaining better exposure information for these different health-effects studies requires both goal-setting for what is needed and mapping out the transition pathway from current capabilities to meeting these goals. Meeting our long-term goals requires definition of incremental steps that provide useful information for the interim and move us toward our long-term goals. Another over-arching theme among the three different pollutants and the different health study approaches is the need for integration among alternate exposure assessment approaches. For example, different groups may advocate exposure indicators, biomonitoring, mapping methods (GIS), modeling, environmental media monitoring, and/or personal exposure modeling. However, emerging research reveals that the greatest progress comes from integration among two or more of these efforts.

Download or read book Development and Evaluation of Portable Passive and Real time Measurement Systems and Dispersion Models to Estimate Exposure to Traffic related Air Pollutants written by Nicola Masey and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This research developed efficient applications of portable measurement systems to assess human exposure to traffic-related air pollution through direct measurement, and evaluation of exposure models.Passive NO2 samplers are deployed at large numbers of sites in epidemiological studies to estimate typical concentrations over 1-4 weeks. I found that deployment time could be reduced to 2 days with limited impact on the accuracy and precision of exposure estimates. This shorter measurement time enabled observation of wind-speed effects leading to overestimation of ambient concentrations by passive samplers. Through development of a post-processing technique and/or inclusion of a membrane I improved sampler accuracy. Portable sensors can provide detailed estimates of personal exposures to air pollution. Many sensor-based monitors have not been subject to rigorous testing procedures to quantify their accuracy. I observed that the most accurate estimates of concentrations from NO2 and O3 sensor-based monitors required regular, intermittent calibration against reference analysers under similar environmental conditions to field measurements. I also found deterioration in BC monitor accuracy and precison when the attenuation of the collection filter exceeded 40 and no improvement in monitor accuracy was observed when filter darkness correction algorithms were applied. Portable sensors can be used to identify locations with higher concentrations, which may require more detailed monitoring. I established that repeated 6-minute measurements of BC and particle number concentrations estimated similar spatial trends to 1-week NO2 measurements using passive samplers. Dispersion models can be used to estimate pollution exposure at multiple locations over a study area. I found that initial user parameterisation in a weather model had limited effect on pollution estimates from a dispersion model. I evaluated a new GIS-based dispersion model (5 x 5 m NO2 estimates for a 3,500 km2 area, with model run times of under 10 minutes). I demonstrated that inclusion of discrete street canyon models and geospatial surrogates (accounting for urban morphology) improved model accuracy. The measurement and modelling evaluation research in this thesis complimented each other by providing efficient ways to directly measure population exposures.

Download or read book WHO Guidelines for Indoor Air Quality written by and published by World Health Organization. This book was released on 2010 with total page 488 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents WHO guidelines for the protection of public health from risks due to a number of chemicals commonly present in indoor air. The substances considered in this review, i.e. benzene, carbon monoxide, formaldehyde, naphthalene, nitrogen dioxide, polycyclic aromatic hydrocarbons (especially benzo[a]pyrene), radon, trichloroethylene and tetrachloroethylene, have indoor sources, are known in respect of their hazardousness to health and are often found indoors in concentrations of health concern. The guidelines are targeted at public health professionals involved in preventing health risks of environmental exposures, as well as specialists and authorities involved in the design and use of buildings, indoor materials and products. They provide a scientific basis for legally enforceable standards.

Download or read book Remote Sensing and Geospatial Technologies in Public Health written by Fazlay S. Faruque and published by MDPI. This book was released on 2018-09-21 with total page 245 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a printed edition of the Special Issue "Remote Sensing and Geospatial Technologies in Public Health" that was published in IJGI

Download or read book Development of Metrics for Individual Exposure Assessment to Traffic Related Air Pollution written by and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This project has explored the use of a variety of methods for assigning exposure to traffic related air pollution. The work has been conducted simultaneously with the collection of health outcome data for an epidemiological study investigating the respiratory and irritant effects of changes in traffic related air pollution. Epidemiological studies investigating the effects of environmental exposures often suffer from poor or inadequate exposure assessment.

Download or read book Exposure Assessment of Air Pollutants written by Christian Monn and published by . This book was released on 1999 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Outdoor Air Pollution written by IARC Working Group on the Evaluation of Carcinogenic Risks to Humans and published by IARC Monographs on the Evaluat. This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This publication represents the views and expert opinions of an IARC Working Group on the Evaluation of Carcinogenic Risk to Humans, which met in Lyon, 8-15 October 2013."

Download or read book A Pseudo Individual Near Real time Measurement for Assessing Air Pollution Exposure in Selected Texas Cities written by Tianfang Bernie Fang and published by . This book was released on 2012 with total page 356 pages. Available in PDF, EPUB and Kindle. Book excerpt: Air pollution causes severe health effects and economic loss. Many major air-pollution-related studies focus on place-based measures and simulation. Typical placebased air pollution studies cannot portray individuals' air pollution exposure scenarios. In recent years, individual-based air pollution exposure measures have been developed rapidly. Based on an extensive literature review of place-based geography and people-based geography, air pollution exposure assessment methods (including place-based and individual-based ones), and health effects of air pollution exposure, this dissertation research aims to investigate an innovative modeling approach for assessing individual near real-time air pollution exposure. The first part of the model development is to design a series of near real-time space-time air pollution scenario cubes. Originating from time geography, space-time cubes provide an approach to integrate spatial and temporal air pollution information into a 3D space. The base of space-time cubes represents the variation of air pollution in a 2D geographical space while the height represents time. The second part of the model development is to geovisualize volunteers' individual real-time space-time trajectories using 3D space-time path maps. The last part of the model development is to integrate space-time cubes and space-time trajectories to develop the pseudo individual near real-time air pollution monitoring (PIRAM in short) models and the derivative models - the integrated pseudo individual near real-time air quality index (PIRAQI in short) models and the integrated pseudo individual near real-time air pollution dose simulation (PIRADS in short) models. Volunteers' individual diurnal ambient ozone (O3) pollution exposures in Houston, Austin, and San Antonio are modeled in this dissertation research. The contributions of this dissertation research are four-fold. First, it can help in understanding air pollution and individual exposure from a people-based geography perspective. Second, it enriches the individual-based air pollution exposure measure study by emphasizing individual travel behaviors in the individual air pollution exposure context. Third, its results can reveal the characteristics of the individual real-time air pollution exposure, which will contribute to local air pollution policy making. Fourth, the PIRAM platform only needs one handheld device terminal, such as a GPS smartphone, which ensure a good end user experience and potential commercial value.

Download or read book Smart Spaces and Places written by Ling Bian and published by Routledge. This book was released on 2021-06-22 with total page 373 pages. Available in PDF, EPUB and Kindle. Book excerpt: Smart technologies have advanced rapidly throughout our society (e.g. smart energy, smart health, smart living, smart cities, smart environment, and smart society) and across geographic spaces and places. Behind these "smart" developments are a number of seminal drivers, such as social media (e.g. Twitter), sensors (drones, wearables), smartphone apps, and computing infrastructure (e.g. cloud computing). These developments have captured the enthusiasm of the public, while inevitably present unprecedented challenges and opportunities for the geographic research community. When meeting the smart challenges, are there emerging theories, methods, and observations that reveal new spatial phenomena, produce new knowledge, and foster new policies? Smart Spaces and Places addresses questions such as how to make spaces and places "smart", how the "smartness" affects the way we think spaces and places, and what role geographies play in knowledge production and decision-making in a "smart" era. The collection of 21 chapters offers stimulating discussion over the meaning of spaces, places, and smartness; scientific insights into smartness; social-political views of smartness; and policy implications of smartness. The chapters in this book were originally published as a special issue of Annals of the American Association of Geographers.

Download or read book Use of Novel Sensors to Assess Human Exposure to Airborne Pollutants and Its Effects on Cognitive Performance written by Maryam Shehab and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Exposure to air pollution can cause adverse health effects, may also adversely affect the central nervous system and affect cognitive performance. Epidemiological studies depend on central site monitors as surrogates to assess personal exposure to air pollution, which can be inaccurate because they do not assess personal exposure in a variety of activities and microenvironments. This thesis aims to assess the level of misclassification in data from central site monitors by using portable modern sensors with high temporal resolution to characterize personal inhaled doses of BC, PM2.5, and UFP, and compare the measurements with surrogate exposure metrics. It also seeks to identify contributing activities and sources associated with the highest concentrations of the three pollutants, and to determine the contribution of these activities and microenvironments to personal exposure, and to study the impact of short-term exposure to air pollution on cognitive function. The first finding is that central site monitors are not a good surrogate for personal exposure. Secondly, travelling in vehicles is linked to the highest concentrations of the three pollutants, while other outdoors activities and outdoors commuting are linked to the highest concentrations of BC and PM2.5, cooking is linked to the highest concentrations of UFP, and activities and time spent indoors are the highest contributors to personal exposure. Thirdly, the results provide strong evidence that short-term exposure to PM2.5 from candle burning and commuting has an adverse effect on cognitive performance.

Download or read book U S Health in International Perspective written by National Research Council and published by National Academies Press. This book was released on 2013-04-12 with total page 421 pages. Available in PDF, EPUB and Kindle. Book excerpt: The United States is among the wealthiest nations in the world, but it is far from the healthiest. Although life expectancy and survival rates in the United States have improved dramatically over the past century, Americans live shorter lives and experience more injuries and illnesses than people in other high-income countries. The U.S. health disadvantage cannot be attributed solely to the adverse health status of racial or ethnic minorities or poor people: even highly advantaged Americans are in worse health than their counterparts in other, "peer" countries. In light of the new and growing evidence about the U.S. health disadvantage, the National Institutes of Health asked the National Research Council (NRC) and the Institute of Medicine (IOM) to convene a panel of experts to study the issue. The Panel on Understanding Cross-National Health Differences Among High-Income Countries examined whether the U.S. health disadvantage exists across the life span, considered potential explanations, and assessed the larger implications of the findings. U.S. Health in International Perspective presents detailed evidence on the issue, explores the possible explanations for the shorter and less healthy lives of Americans than those of people in comparable countries, and recommends actions by both government and nongovernment agencies and organizations to address the U.S. health disadvantage.

Download or read book Improving Exposure Response Estimation in Air Pollution Health Effects Assessments written by Bernard Sam Beckerman and published by . This book was released on 2014 with total page 115 pages. Available in PDF, EPUB and Kindle. Book excerpt: Of the 3.7 million deaths attributed to outdoor air pollution, ischemic heart disease (IHD) represents 40% of the total deaths, or approximately 1.48 million deaths, which occur mainly in older adults. IHD is the largest single causes of death attributable to ambient air pollution. Research on the progression and incidence of IHD are pointing to ambient fine particulate matter (PM) as a major contributor to morbidity and mortality outcomes. In this context, improvements in air pollution exposure assessment methods and health effects assessments are developed and investigated in this thesis. With the exposure assessment, methods and tools were created that had utility for improving air pollution exposure assessment. Two exposure assessment chapters are presented. The first of these is focused on the creation of a national-level spatio-temporal air pollution exposure model. In the second exposure chapter, emphasis is placed on the development and evaluation of methods used to estimate annual average daily traffic - a local source of ambient particulates and other air pollutants thought to have heightened toxicity. A model was created to predict ambient fine particulate matter less than 2.5 microns in aerodynamic diameter (PM2.5) across the contiguous United States to be applied to health effects modeling (Chapter 2). We developed a novel hybrid approach that combine a land use regression model (LUR) and Bayesian Maximum Entropy (BME) interpolation of the LUR space-time residuals,. The PM2.5 dataset included observations at 1,464 monitoring locations with approximately 10% of locations reserved for cross-validation across the contiguous United States. In the LUR, variables based on remote sensing estimates of PM2.5, land use and traffic indicators were made available to the Deletion/Substitution/Addition machine learning algorithm used to select predictive models describing local variability in PM2.5. Two modeling configurations were tested. The first included all of the available covariates; and the second did not include the remote sensing. The remote sensing variable was not based on any ground information. Specific results showed that normalized cross-validated R2 values for LUR were 0.63 and 0.11 with and without remote sensing, respectively; suggesting remote sensing is a strong predictor of ground-level concentrations. In the models including the BME interpolation of the residuals, cross-validated R2 were 0.79 for both configurations; the model without remotely sensed data described more fine-scale variation than the model including remote sensing. Our results suggest that our modeling framework effectively predicts ground-level concentrations of PM2.5 at multiple scales over the contiguous U.S. The network interpolation tool used to estimate traffic is described in Chapter 3. The program was created using free open-source software, namely Python 2.7 and its related libraries. It was applied to two county study areas in California, USA (Alameda and Los Angeles), where inverse distance weighted (IDW) and kriging annual average daily traffic (AADT) models were estimated. These estimates were compared to: each other; to an entirely independent dataset; and against a traffic model using similar methods to those used in the traffic estimates employed in the exposure model in Chapter 2. Results show different levels of predictive agreement. Using cross-validation methods, the R2 for these models were 0.36 and 0.32 in Alameda and 0.46 and 0.47 in Los Angeles, for IDW and Kriging, respectively. Differences in model performance seen between and within the study area suggest that data issues may have materially contributed; these include: temporal discordance in the measurements and mischaracterization of road types. A comparison of network interpolation methods to those used to estimate traffic in Chapter 2 found the network methods to be superior. For the health effects analysis that that estimated an exposure response curve describing the effect of PM2.5 on ischemic heart disease mortality, monthly ambient PM2.5 estimates (from the model outlined in Chapter 2) were averaged to represent long-term exposure at the home. Super Learner evaluated 14 models that fell within the classes of parametric, semi-parametric, and non-parametric models. A generalized additive model with splined terms was identified as being most predictive of life expectancy. Over the range of exposure 3-27 μg/m3 the estimated years of life lost over this interval was 0.6 years. This relationship, however, was not linear. It followed the pattern reported in previous studies with increased risk rates at lower exposures and a flattening out of the curve at higher exposures. An inflection point appeared to occur near 10 μg/m3. These estimates failed to reach significance at the 95% confidence criteria but were close enough to be suggestive of a relationship. Results from a complementary simulation showed that left truncation characteristics of the cohort likely biased to results towards the null. In addition, the use of inverse probability of censoring weights to control for bias induced by right censoring added variability to the estimator that likely reduced the power to detect and effect. This research has shown the utility of machine-learning algorithms for improving health effects assessments in the field of air pollution epidemiology. In exposure science, they have proven their utility in creating estimates of exposure that can be used to characterize multiple scales of variability. In health effects assessments, in combination with causal inference methods, this work has shown the utility of these methods to detect non-linear effects in novel parameter estimates in individual cohort studies. In addition to the methodological contribution, the health effects results contribute to the discussion about the burden of disease attributable to particulate matter.

Download or read book Quantitative Risk Analysis of Air Pollution Health Effects written by Louis Anthony Cox Jr and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book highlights quantitative risk assessment and modeling methods for assessing health risks caused by air pollution, as well as characterizing and communicating remaining uncertainties. It shows how to apply modern data science, artificial intelligence and machine learning, causal analytics, mathematical modeling, and risk analysis to better quantify human health risks caused by environmental and occupational exposures to air pollutants. The adverse health effects that are caused by air pollution, and preventable by reducing it, instead of merely being statistically associated with exposure to air pollution (and with other many conditions, from cold weather to low income) have proved to be difficult to quantify with high precision and confidence, largely because correlation is not causation. This book shows how to use recent advances in causal analytics and risk analysis to determine more accurately how reducing exposures affects human health risks. Quantitative Risk Analysis of Air Pollution Health Effects is divided into three parts. Part I focuses mainly on quantitative simulation modelling of biological responses to exposures and resulting health risks. It considers occupational risks from asbestos and crystalline silica as examples, showing how dynamic simulation models can provide insights into more effective policies for protecting worker health. Part II examines limitations of regression models and the potential to instead apply machine learning, causal analysis, and Bayesian network learning methods for more accurate quantitative risk assessment, with applications to occupational risks from inhalation exposures. Finally, Part III examines applications to public health risks from air pollution, especially fine particulate matter (PM2.5) air pollution. The book applies freely available browser analytics software and data sets that allow readers to download data and carry out many of the analyses described, in addition to applying the techniques discussed to their own data.