The aims of the studies underlying this thesis were to assess the exposure to quartz in Swedish iron foundries and to determine the cancer morbidity for Swedish foundry workers. A cohort of 3,045 foundry workers and a final measurement database of 2,333 number of samples was established. The exposure measurements showed high levels of respirable quartz, in particular for fettlers and furnace and ladle repair workers with individual 8 hr TWA (GM=0.041 and 0.052 mg/m3; range 0.004-2.1 and 0.0098-0.83 mg/m3). In our database, the quartz concentrations as 8hr TWAs of current and historical data varied between 0.0018 and 4.9 mg/m3, averaging 0.083 mg/m3, with the highest exposures for fettlers (0.087 mg/m3) and furnace and ladle repair workers (0.42 mg/m3). The exposure for workers using respirators assuming full effect when used were assessed quantitatively, revealing workers with actual exposure exceeding the occupational exposure limits. Overall cancer morbidity was not increased, but the incidence of lung cancer was significantly elevated (SIR 1.61; 95 % CI 1.20-2.12). In the cohort study, significant associations between lung cancer and cumulative quartz exposure were detected for quartz doses of 1-2 mg/m3 * year (SIR 2.88; 95 % CI 1.44-5.16) and >2 mg/m3 * year (SIR 1.68; 95 % CI 1.07- 2.52). These findings were not confirmed in the case-control analysis. The agreement between the estimated exposure in our early historical model and the development model showed a regression coefficient of 2.42, implying an underestimation of the historical exposure when using the development model data. The corresponding comparison between the development and the validation model based on our survey data showed a B of 0.31, implying an overestimation of present exposures when using data from the validation model. The main conclusions of the thesis are that certain foundry workers are still exposed to high levels of quartz, and the overall excess lung cancer could not be confirmed in the exposure-response analysis.

Arsenic exposure has been associated with decreased club cell secretory protein (CC16) levels in adults. Further, both arsenic exposure and decreased levels of CC16 in childhood have been associated with decreased adult lung function. Our objective was to determine if urinary CC16 levels in children are associated with arsenic concentrations in environmental media collected from their homes. Yard soil, house dust, and tap water were taken from 34 homes. Urine and toenail samples were collected from 68 children. All concentrations were natural log-transformed prior to data analysis. There were associations between urinary CC16 and arsenic concentration in soil (b = -0.43, p = 0.001, R-2 = 0.08), water (b = -0.22, p = 0.07, R-2 = 0.03), house dust (b = -0.37, p = 0.07, R-2 = 0.04), and dust loading (b = -0.21, p = 0.04, R-2 = 0.04). In multiple analyses, only the concentration of arsenic in soil was associated with urinary CC16 levels (b = -0.42, p = 0.02, R-2 = 0.14 (full model)) after accounting for other factors. The association between urinary CC16 and soil arsenic may suggest that localized arsenic exposure in the lungs could damage the airway epithelium and predispose children for diminished lung function. Future work to assess this possible mechanism should examine potential associations between airborne arsenic exposures, CC16 levels, lung function, and other possible confounders in children in arsenic-impacted communities.

Understanding the short-and long-term impacts of a biomonitoring and exposure project and reporting personal results back to study participants is critical for guiding future efforts, especially in the context of environmental justice. The purpose of this study was to evaluate learning outcomes from environmental communication efforts and whether environmental health literacy goals were met in an environmental justice community. We conducted 14 interviews with parents who had participated in the University of Arizona's Metals Exposure Study in Homes and analyzed their responses using NVivo, a qualitative data management and analysis program. Key findings were that participants used the data to cope with their challenging circumstances, the majority of participants described changing their families' household behaviors, and participants reported specific interventions to reduce family exposures. The strength of this study is that it provides insight into what people learn and gain from such results communication efforts, what participants want to know, and what type of additional information participants need to advance their environmental health literacy. This information can help improve future report back efforts and advance environmental health and justice.

Background: Sun exposure is strongly associated with skin cancer. Sun protection to reduce harmful effects of sun exposure, including skin cancer, is encouraged. However, sun sensitivity, a possible confounder of the association between sun exposure and sun protection, is often overlooked. Objectives: This study examined how sun exposure and sun protection behaviors among indoor workers vary between sun sensitive and less sun sensitive individuals. Methods: Diaries over 45 days (August and September of 2009) from indoor workers in the Midwest were examined. Diaries included daily sun exposure, sun protection, and sun sensitivity. Sun sensitivity was measured by determination of fair and non-fair complexion, categorized based on inability to tan and tendency to sunburn. Sun exposure was compared between fair and non-fair complexion. Total exposure (sunrise to sunset) was examined, along with exposure between 10 am and 4 pm, and long exposure between 10 am and 4 pm (at least 60 minutes). Percentages of time in the sun spent practicing sun protection were reported by study participants with fair and non-fair complexion. Logistic regression was used to determine odds ratios between fair complexion and mean sun exposure and mean sun protection times. Results: Fair complexioned individuals spent less time in the sun than non-fair complexioned individuals. In addition, fair complexioned individuals spent greater percentages of time practicing sun protection behaviors while they were in the sun. They were more likely to practice sun protection behaviors related to sunscreen application and protective clothing, notably, wearing a long-sleeved shirt.Conclusion: Fair complexioned individuals spend less time in the sun and practice more sun protective behaviors than non-fair complexioned individuals. These interrelations between sun sensitivity, sun protection and amount of sun exposure suggest that controlling for potential confounding when examining one of these factors and skin cancer may be challenging.

<p>U disertaciji je predložen i razvijen metod procene izloženosti za<br />širokopojasna merenja nivoa električnog polja visokih frekvencija.<br />Metod je baziran na određivanju granica izloženosti, kao i njihovom<br />prilagođenju spektralnom sadržaju polja na mernoj lokaciji. Verifi-<br />kacija razvijenog metoda je obavljena analizom rezultata eksperimen-<br />talnih merenja u realnim uslovima.</p> / <p>One new exposure assessment approach for broadband measurements of the<br />high-frequency electric field strength is proposed and developed in the thesis.<br />The approach is based on the determination of the upper and lower<br />exposure boundaries, as well as their adaptation to the specral content of the<br />field at the measurement location. The verification of the developed<br />approach was performed by analyzing the results of experimental<br />measurements in real conditions.</p>

This study examined the effects of the presence of fungal growth on the phthalate ester content of plasticized polyvinyl chloride (pPVC) used as the vapor barrier component of metal building insulation and the impact the fungal growth may have on the resulting exposure potential to the workers in the building. Individual pieces of the pPVC material exhibiting fungal growth and individual pieces of the pPVC material exhibiting no fungal growth were collected from the building being investigated. Twenty-five pieces each of the pPVC material exhibiting fungal growth and of the pPVC material exhibiting no fungal growth were weighed, reduced to small pieces, and extracted with dichloromethane. The extracts were analyzed using a gas chromatograph coupled with a mass spectrometer. The phthalate content of four phthalate esters identified in the pPVC: diethyl phthalate (DEP), dibutyl phthalate (DBP), butyl benzyl phthalate (BBP), and di-(2-ethylhexyl) phthalate (DEHP), was quantified and the results extrapolated to concentration based on weight ([um]g/Kg) and area ([um]g/m2). A paired samples t test and independent samples t test was used to identify where significant differences occurred (α = 0.05) in the phthalate content between pieces. Using the mean concentration for each phthalate ester, a worst-case-scenario exposure was modeled. There was a statistically significant difference in the phthalate ester content between the pPVC exhibiting fungal growth and pPVC exhibiting no fungal growth for all four phthalate esters investigated. The mean phthalate ester concentration ranged from 13.74 [um]g/m2-34.94 [um]g/m2 in the pPVC exhibiting no fungal growth and 12.00 [um]g/m2-30.63 [um]g/m2 in the pPVC exhibiting fungal growth. The modeled exposure concentration in the building ranged from 0.39 [um]g/m3-0.98 [um]g/m3 and was generally lower than published exposure concentrations in similar settings.

The objective of the three studies in this dissertation was to improve methods to prevent musculoskeletal disorders among workers in high-risk occupations. The first two studies, Strain Index (SI) Studies I & II, addressed this problem by better characterizing the performance of a commonly used observational method of estimating potentially hazardous biomechanical exposures, the SI. The SI combines measures of several biomechanical risk factors into a single value (SI score). Strain Index scores are usually categorized into four ordinal SI "risk categories." In Strain Index Study I, multivariate survival analysis models were compared to evaluate the predictive validity of the original SI risk category cut-points to a new set of empirically derived cut-point values among 276 manufacturing workers. The results from this prospective study indicated that the empirically derived cut-points were a better predictor of incident hand-arm symptoms than the original cut-points, especially among women. In Strain Index Study II, Aim 1, exposures to forceful exertions, repetition and non-neutral wrist posture estimated with SI methods were compared to analogous exposures estimated with alternate methods. Statistically significant associations between separate methods designed to assess specific risk factors were observed only for those measuring non-neutral wrist posture. In Aim 2, a multivariate survival analysis model examining associations between incident hand-arm symptoms and biomechanical exposures estimated with the SI was compared to a model examining associations between incident hand-arm symptoms and biomechanical exposures estimated with separate estimates of biomechanical risk factors. Results favored the SI risk category metric to characterize biomechanical exposures compared to separate measures of exposure. he third study, light-weight block (LWB) Intervention Study, was a repeated measures laboratory study of 25 bricklayers performed to estimate the effect of block weight (LWB vs. standard-weight block (SWB)) and course height on low back disorder (LBD) risk factor exposure. Mixed-effect models showed that LWB was associated with reduced exposure for percent time spent in sagittal flexion >30°, lifting rate, LBD risk probability score, and non-dominant upper trapezius muscle activity. Bricklaying at ankle or chest heights was generally associated with higher exposure to risk factors than bricklaying at knuckle height.

Ce travail de recherche s'inscrit dans le contexte d'une étude épidémiologique de cohorte. De septembre 1999 à décembre 2003, une vaste étude longitudinale comportant 2 ans de suivi avait été lancée en Belgique grâce à un financement de la Politique Scientifique Fédérale (PSF). Elle sintitulait: "Etude de cohorte des déterminants étiologiques et pronostiques des maux de dos liés à la profession". Cette étude était conduite par plusieurs centres de recherche . Dans un souci de visibilité internationale, elle porte le nom de BELCOBACK Study (BELgian COhort study on low BACK pain). Comme toute étude épidémiologique, l'étude BELCOBACK vise à mettre en relation l'exposition à une série de facteurs de risque et l'apparition de plaintes en relation avec une problématique de santé. Ainsi, la précision de cette relation dépend à la fois de la précision de l'estimation de l'exposition et de la précision de l'estimation de l'effet santé. Dans le contexte présent, l'effet santé correspond à l'apparition d'un épisode de lombalgie dont l'objectivation est davantage basée sur le symptôme que sur des critères cliniques. Ainsi, en épidémiologie, le questionnaire est bien la méthode de choix pour évaluer la lombalgie. La précision avec laquelle l'exposition est évaluée est moins consensuelle et plus complexe car un plus grand choix de méthodes est possible. Dans ce domaine, les méthodes les plus précises, comme les mesures directes par instrumentation du sujet, sont aussi les plus coûteuses et les plus difficiles à appliquer à un large effectif. Or, dans toute étude épidémiologique, l'effectif doit être important pour des raisons de puissance statistique. En sachant qu'il existe un cadre budgétaire limitatif, il est donc généralement nécessaire d'aboutir à un compromis de "coût-précision" dans le choix des méthodes d'évaluation à mettre en uvre. L'étude BELCOBACK ne faisant pas exception à cette règle, le choix des méthodes d'évaluation est donc au centre de ce travail. L'objectif de celui-ci consiste à évaluer l'exposition professionnelle aux facteurs de risque mécaniques de la lombalgie, en utilisant une méthodologie qui présente une précision suffisante tout en restant dans des limites de coûts acceptables. Un état de la question sera dabord présenté. Il vise à résumer lépidémiologie de la lombalgie dans la population générale et dans la population active, les méthodes dévaluation de la lombalgie, les facteurs de risque professionnels de la lombalgie et leurs méthodes dévaluation. Dans létude BELCOBACK, les deux instruments de mesures retenus pour lévaluation des risques mécaniques de la lombalgie étaient le questionnaire auto-administré et les observations directes. Les deux premiers chapitres sont dès lors consacrés au développement et à la validation de ces instruments. Le dernier chapitre est, quant à lui, consacré à létude des relations entre lincidence des lombalgies et le niveau dexposition évalué par les méthodes développées.

The purpose of this thesis was to assess the possible risk of myocardial infarction in work entailing exposure to vibration, and to study whether there is any relation between short-term exposure to vibration and cardiac regulation. Epidemiological methods were applied to investigate a possible association between occupational exposure to vibration and myocardial infarction. Two study populations were used; one case-control study (n=475) and one cohort of iron-ore miners in Kiruna and Malmberget, Sweden (n=13621). In the former, the cases were first-time myocardial infarction patients and the controls were selected to match for sex, age and hospital catchment area. Job-exposure matrixes for vibration were established for both the case-control study and the cohort study. In order to study acute effects on cardiac regulation, an experimental study was conducted on healthy subjects (n=20) who were exposed to hand-arm vibration exclusively and in combination with exposure to noise. The effect on the autonomic balance was measured by heart rate-variability. In the case-control study, an increased risk of contracting myocardial infarction was found among occupations entailing vibration exposure. The results from the cohort show an increased risk of myocardial infarction mortality compared to a reference population. The increment was higher for those younger than 60 years. Relative risks for myocardial infarction mortality increased with increasing exposure to vibration in the group at working-age and the increased risk remained after adjusting for exposure to dust. In the experimental study, exposure to hand-arm vibration was found to acutely affect the autonomic nervous system as the total heart-rate variability decreased during exposure to hand-arm vibration. To conclude: work entailing exposure to vibration is a risk factor for myocardial infarction, increased myocardial infarction mortality attributed to exposure to vibration seems to be mainly observed at working-age, and exposure to hand-arm vibration acutely decreases heart-rate variability and thus affects heart-rate regulation.

The objective of this study was to investigate the exposure assessment and health risk of particulate matter emitted from steel industry for high-risk inhabitants living in metro Kaohsiung. A steel plant and an electric arc plant were selected for conducting the sampling of particulate matter (PM). The physical and chemical properties of PM sampled at the working place and at the fence of selected plants were also analyzed to establish the fingerprints of PM in the steel industry. In order to accomplish this study, both personal sampling and environmental sampling were conducted in steel plants. Personal exposure sampling was undertaken at working places, while the conduction of environmental sampling might affected by various uncertain environmental factors (such as meteorological condition and other emission sources), but it could characterize the overall environmental situation and help exposure assessment. Moreover, The exposure of employers (including manufacturing workers and supporting staffs) could be further assessed based on the concentration and duration of PM exposure. Specific metal concentration was obtained from working environment, searching for exposure parameter (such as exposure frequency, exposure duration, body weight, average time, and etc.) and toxicity database (e.g. cancer slope factor and reference dose). The data could be used for assessing both cancer risk and non-cancer risk of specific heavy metal. Sampling data obtained from working places showed that the highest PM concentration were observed during the electric arc process, especially the charging and discharging procedures. The concentration of PM1.0, PM10, and TSP at the working places were 53.3~195.6 £gg/m3 ,365.7~550.0 £gg/m3, and 1085.5~2755.0 £gg/m3, respectively. Measured at the outdoor environments of working places, the highest PM10 and TSP concentration, ranging from 365.7~550.0 £gg/m3 and 1085.5 ~2755.0 £gg/m3, were observed at the sinter plants of a steel manufacturer. Sampling data obtained at the fence of steel plants (a steel plant and electric arc plant) indicated that the concentration of PM10 and TSP exceeded the ambient air quality standards. Modification of manufacturing process and improvement of PM collection system are highly required to reduce the concentration level as well as the emission of PM. Results of fingerprint of PM (PM2.5, PM2.5-10, TSP) obtained from working places showed that iron, calcium, sulfate, nitrate, calcium ion, and elemental carbon were the major chemical content of PM at the melting plant, the sinter plant, and the storage field. While, iron, calcium, sulfate, nitrate, calcium ion, and organic carbon were the major chemical content of PM at electric arc plant. Results of personal exposure concentration and exposure dose of PM showed that the highest exposure level of both manufacturing workers and supporting staffs were observed at the storage field, while the lowest exposure level was found at the sinter plant. Therefore, enforcement of wearing maskers and/or shelters at the storage field is also highly recommended to prevent manufacturing workers from the exposure of high-level PM at working places. Moreover, the cancer risk of manufacturing workers exposured to hexavalent chromium (Cr6+) at the melting plant, the sinter plant, the storage field, and the electric arc plant exceeded acceptable cancer risk standard (10-5~10-6), while the hazard index of manganese (Mn) was much higher than other metals.Meanwhile, exposuring to Cr6+, Ni, and Mn at the electric arc plant also exceeded acceptable standards (Cr6+ and Ni¡G10-5~10-6 , Mn¡G1). Several control strategies, including pollution reduction measures such as the usage of clean fuel, process modification, the improvement of collection system, the enhancement of manufacture management, the conduction of environmental monitoring and exposure assessment, floor cleanup and truck entrance management, are recommended to improve the contamination of PM at working places and surrounding environments for metallurgic industries. Moreover, enforcement of wearing maskers and/or shelters at high-risk environments is also highly recommended to prevent manufacturing workers from the exposure of high-level PM at working places. Keywords: steel industry, particulate matter sampling, physical and chemical characteristics, exposure assessment, health risk