No description available.

This thesis investigates the range, distribution and causes of high radon levels in dwellings in the Brighton area of Southeast England. Indoor radon levels were measured in more than 1000 homes. The results show that high radon levels can arise in an area previously considered to offer low radon potential from local geological sources. Climate and building-related factors were found to affect significantly the radon levels in dwellings. Multiple regression was used to determine the influence of the various factors on indoor radon levels and an empirical model developed to predict indoor radon levels. The radon hazard, independent of building-related effects, was determined for each surveyed location by adjusting the radon measurement to that expected on the ground floor of a 'model' dwelling. This standardised set of radon levels was entered into a geographical information system (GIS) and related to surface geology. The geometric mean radon level for each lithological unit was plotted to produce a radon hazard map for the area. The highest radon levels were found to be associated with the youngest Chalk Formations, particularly where they meet overlying Tertiary deposits, and with Clay-with-Flints Quaternary deposits in the area. The results were also converted to the radon activity equivalent to that expected from the NRPB's standard dual-detector dwelling survey method and analysed by lognormal modelling to estimate the proportion of dwellings likely to exceed the UK Action Level of 200 Bq/m3 for each lithological unit. The likely percentages of dwellings affected by radon thus obtained were mapped to lithological boundaries to produce a radon potential map. The radon hazard map and the empirical radon model facilitate the prediction of radon levels in dwellings of comparable construction and above similar geology and should further the understanding of the behaviour of radon gas in buildings to allow indoor radon concentrations to be controlled. The radon potential map is directly comparable with those produced by NRPB and BGS and can be used to assist in environmental planning and development control.

<p>Cardiovascular disease and diabetes are a growing problem around the world and both considered leading causes of death in the United States. Cardiovascular disease is often not diagnosed until it advances to causing serious problems such as heart attacks. Diabetes can greatly increase the risk of cardiovascular disease so diagnoses is important. Metabolic syndrome is a relatively easy way to predict who is at risk of these diseases or to make an early diagnoses. The syndrome is diagnosed in patients that meet 3 or more criteria relating to obesity, blood pressure, triglycerides, cholesterol, and glucose in an individual. Calcium scores, a result of a specific body scan, are a good indicator of cardiovascular disease but are not commonly performed. Metabolic syndrome can be diagnosed using information from a routine physical with blood work. This paper observed the prevalence rate of metabolic syndrome in a cohort of police officers who responded to the September 11th attack at the World Trade Center in New York City. In our study population, the prevalence of metabolic syndrome was 26%. We also found a correlation between calcium scores and the number of metabolic syndrome criteria met; patients meeting all 5 criteria had significantly higher calcium scores with a p-value of .02 and 95% confidence interval of 1.084-2.583.

An outbreak of Middle East Respiratory Syndrome (MERS) among healthcare workers in Saudi Arabia in 2012 led to an investigation of hand-hygiene behaviors among healthcare professionals. Direct contact with patients is a major pathway for MERS, a droplet virus, which refers to a virus that lays on surfaces. This study investigated factors associated with respiratory disease transmission (e.g., MERS) in hospital settings among healthcare workers (i.e., physicians and nurses). I developed a 16-item checklist based on three sources: the CDC standards, the WHO Five Moments for Hand Hygiene, and Boyce and Pittet's (2002) guidelines of hand hygiene. I used those 16 items in both direct-observation and self-reported questionnaire formats. The checklist addressed three time frames of contact: before, during, and after contact with patients, devices, and surrounding surfaces. Hand-hygiene behaviors surrounding these time frames were assessed. The study also explored healthcare workers' beliefs about hygiene practices by comparing personal reports of hand hygiene assessed by questionnaire to observed actual hand-hygiene practices. The study was a cross-sectional research design and was conducted in the outpatient examination rooms and emergency departments of three hospitals (public, private, and military) in the Eastern region of Saudi Arabia. The total sample size included 87 physicians and nurses who were recruited while on duty during the researcher's observation periods. To provide clear results, I used two independent sample t-tests to test each of the 8 hypotheses. I found that no statistically significant differences were found among health-care workers when observing their behaviors of hand-hygiene practices. However, when using the self-reported questionnaire data, I found statistically significant differences between physicians' and nurses' hand-hygiene practices before, during, and after interacting with patients. Also, I found statistically significant differences between male and female hand-hygiene practices during interacting with patients, and I found statistically significant differences between health-care workers in public and military hospitals hand-hygiene practices during interacting with patients. For the primary hypothesis, I used Pearson correlation to determine the relationship between healthcare workers' reports of hand-hygiene practices, and observed healthcare workers behaviors of hand-hygiene practices. I found that no statistically significant correlation between the two data collection instruments. To provide a further analysis, a multivariate analysis of covariance (MANCOVA) was used to examine whether healthcare workers' hand-hygiene practices before, during, and after were different while controlling for their gender, department, and hospital type. I found that no statistically significant differences were found when observing the healthcare workers behaviors of hand-hygiene practices. However, when using the self-reported questionnaire data, I found that nurses and females reported better hand-hygiene than physicians and males. From these data, I conclude healthcare workers understand the importance of hand-hygiene and fail to appropriately implement the practice.

<p> Farmworkers and their families may experience increased levels of agricultural pesticides in their homes due to both (1) take-home/soil track-in on shoes, clothes and skin, and (2) air infiltration from nearby agriculture fields via agricultural pesticide drift in the vapor phase or adhered to resuspended soil particles. This dissertation estimates the relative contributions o the take-home/soil track-in and air infiltration pathways of agricultural pesticides into homes, as well as identifies the risk factors for increased in-home agricultural pesticide levels for farmworkers and their families living near agriculture fields. Samples of outdoor air, yard soil, and house dust from 21 farmworkers' homes in Yuma County, Arizona were collected and analyzed for a suite of agricultural pesticides. To capture household information, such as behaviors, demographics, and housing structure, a participant questionnaire was administered at the time of the sampling. A pesticide transport model was developed, evaluated, and applied to quantify relative contributions of the air infiltration and the take-home/soil track-in pathways of agricultural pesticides into the house dust of the farmworkers&rsquo; homes. To explore a wide-range of potential risk factors for increased agricultural pesticide levels in the homes, traditional statistical methods and Classification and Regression Tree (CART) analyses were used. The results of this study, found that the air infiltration pathway contributes to over 90% of some agricultural pesticides in the house dust found in the farmworkers&rsquo; homes. In addition, among the influential risk factors for increased in-home agricultural pesticide levels was the home being a closer distance to an agricultural field, as well as the home having carpeted floors, more farmworkers per square footage of the home, and less months of heating and cooling the home. It is suggested that future intervention efforts to reduce in-home agricultural pesticide levels put more emphasis on targeting the air infiltration pathway, and take into consideration relevant risk factors for increased pesticide levels in the home.</p>

The issue of particulate matter (PM) and associated health and environmental problems has been subjected to extensive research in a number of countries. However, there are no recent studies concerning the physical and chemical properties of PM from urban Cardiff. Measurements were made to study particulate matter, their sources, chemical compositions, gaseous precursors and their seasonal variations in urban Cardiff (latitude: 51° 28´ 59.47¨N and longitude: 03° 09´ 58.08¨W) from December 2009 to November 2010. A low volume air sampler for PM10 and PM2.5 particles, and real-time air samplers for TSP, PM10, PM2.5, PM1, NO, NO2, NOx, SO2 and VOCs were used during sampling. The collected ambient air suspended particles were analysed for seven major ions (Cl−, NO3−, SO42−, Ca²⁺, Mg²⁺, K⁺ and Na⁺) and 12 elements (Na, Mg, Al, K, Ca, Cr, Fe, Ni, Cu, Zn, Cd and Pb) by using an ion chromatography and atomic absorption spectrometer respectively. Cl⁻, SO42− and NO3− were generally the major ions in fractions of PM10 and PM2.5, while the elements Na, Mg, Ca, Al, K, and Fe were the most abundant elements. A good correlation was observed between PM10 and PM2.5 indicating that PM10 and PM2.5 contribute significantly to PM levels in urban Cardiff. Most of the ions and elements in both PM fractions were abundant in the winter season. Natural sources were the highest contributors followed by anthropogenic sources for the analysed elements in PM10 and PM2.5. Enrichment factor (EF) analysis showed the enrichment factor was higher in PM10 and PM2.5 elements such as Zn, Pb, Cu, Cr and Cd. The high enrichment factor of these elements in urban Cardiff suggested that the dominant sources for these elements were non-crustal. Real-time measurements of PM precursor gases did not exceed the standard concentrations given by the Air Quality Strategy (AQS) for these pollutants.

No description available.

<p> The valleys of northern Utah, where most of Utah&rsquo;s population resides, experience episodic air pollution events well in excess of the National Ambient Air Quality Standards. Most of the events are due to an accumulation of particulate matter during persistent cold air pools in winter from both direct emissions and secondary chemical reactions in the atmosphere. High wintertime ozone concentrations are occasionally observed in the Uintah Basin, in addition to particulate matter. At other times of the year, blowing dust, wildland fires, fireworks, and summertime ozone formation contribute to local air pollution. The objective of this dissertation is to investigate one facet of the health effects of Utah&rsquo;s air pollution on its residents: the acute impacts of air pollution on gastrointestinal (GI) disease.</p><p> To study the health effects of these episodic pollution events, some measure of air pollution exposure must be matched to the health data. Time and place are used to link the health data for a person with the pollution data. This dissertation describes the method of kriging data from the sparse pollution monitoring network to estimate personal air pollution history based on the zip code of residence. This dissertation then describes the application of these exposure estimates to a health study on GI disease.</p><p> The purpose of the GI study is to retrospectively look at two groups of patients during 2000-2014: those with autoimmune disease of the GI tract (inflammatory bowel disease, IBD) and those with allergic disease of the GI tract (eosinophilic esophagitis, EoE) to determine whether disease exacerbations occur more commonly during and following periods of poor air quality compared to periods of good air quality. The primary analysis method is case crossover design. In addition to using the kriged air pollution estimates, the analysis was repeated using simpler empirical estimation methods to assess whether the odds ratios are sensitive to the air pollution estimation method.</p><p> The data suggests an association between particulate matter smaller than 2.5 microns and prednisone prescriptions, gastrointestinal infections in general, clostridium difficile infections specifically, and hospitalizations among people who have at least five entries of IBD diagnosis codes in their medical records. EoE exacerbations appear to be associated with high concentrations of particulate matter as well as ozone.</p>

The thesis investigates the value of quantitative analyses for historical studies of science through an examination of research trends in insect pest control, or economic entomology. Reviews are made of quantitative studies of science, and historical studies of pest control. The methodological strengths and weaknesses of bibliometric techniques are examined in a special chapter; techniques examined include productivity studies such as paper counts, and relational techniques such as co-citation and co-word analysis. Insect pest control is described. This includes a discussion of the socio-economic basis of the concept of `pest'; a series of classifications of pest control techniques are provided and analysed with respect to their utility for scientometric studies. The chemical and biological approaches to control are discussed as scientific and technological paradigms. Three case studies of research trends in economic entomology are provided. First a scientometric analysis of samples of chemical control and biological control papers; providing quantitative data on institutional, financial, national, and journal structures associated with pest control research fields. Second, a content analysis of a core journal, the Journal of Economic Entomology, over a period of 1910-1985; this identifies the main research innovations and trends, in particular the changing balance between chemical and biological control. Third, an analysis of historical research trends in insecticide research; this shows the rise, maturity and decline of research of many groups of compounds. These are supplemented by a collection of seven papers on scientometric studies of pest control and quantitative techniques for analysing science.

Current concepts concerning nicotine's central nervous system (CNS) mechanism(s) of action suggest that this drug is producing its effects via an interaction at nicotiniccholinergic receptors (nAChRs) which open a membrane cation channel. Following initial opening of the channel, nicotine appears to induce a rapid desensitization of the nAChRs, closing the channel and resulting in a cessation of nicotine's effects. Research presented here will provide evidence of this secondary desensitization process in vivo by demonstrating nicotine's ability to induce acute tolerance in the discriminative stimulus (DS) paradigm. The ability of nicotine to elicit DS control of behavior was significantly reduced via challenge doses of (800, 1200, and 1600 ugjkg, s.c.) of nicotine administered 60-180 minutes prior to the training dose (400 ugjkg, s.c.). Eight out of twenty rats demonstrated this phenomena, with time and dose varying, suggesting that these effect may be contingent upon the individual rat studied. It appears that we have found a means of investigating cellular mechanisms in vivo using operant behavior.