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    Inhalation of Nebulized Diesel Particulate Matter: A Safety Trial in Healthy Humans
    (2014-02-14) Dorman, Sandra
    Diesel particulate matter (DPM) has adverse health effects. Examining the underlying pathophysiological mechanisms would be facilitated by the introduction of an exposure method that is safe, portable, and cost-effective. The purpose of this study was to establish a novel method to study DPM exposure via nebulization and an inhalation dose that was safe, yet capable of eliciting an inflammatory response. Ten participants enrolled in this nonblinded, nonrandomized study. Subjects inhaled nebulized 0.9% saline and increasing doses of DPM suspended in 0.9% saline (75, 150, and 300 𝜇g) in a sequential manner. FEV1 was measured repeatedly during the first 2 h after exposure and blood, oximetry, sputum, and heart rate were taken before, 2 h, and 24 h after inhalation challenge. DPM inhalation was well-tolerated at all doses. A decrease in FEV1 was observed after each inhalation challenge (including saline). Inhalation of 300 𝜇g DPM produced a significantly different FEV1 response curve. An increase in particle inclusion-positive sputum macrophages for all DPM doses confirmed that the nebulized particles were reaching the lower airways. SerumGM-CSF was elevated after exposures to 150 and 300 𝜇gDPM.No other inflammatory changes were detected.DPM inhalation via nebulizer is a safe method of delivering low doses of DPMs in healthy people.
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    Smoke Exposure Has Transient Pulmonary and Systemic Effects in Wildland Firefighters
    (2014-01-30) Dorman, Sandra
    Respiratory exposure to air pollutants is associated with cardiovascular morbidity and mortality and firefighters have been shown to be at an increased risk of work-related cardiovascular events. Wildland firefighters experience intermittent, intense exposure to biomass smoke. The aim of this study was to characterize the respiratory and systemic effects of smoke exposure in wildland firefighters. Seventeen seasonal firefighters from a northeastern Ontario community were recruited at the beginning of the fire season and baseline measurements obtained; postexposure measurements were made at various times within 16 d of firefighting. Spirometric measurements showed a transient decline in forced vital capacity within 7 d of fire exposure, not evident by 8–16 d. Induced sputum showed a significant increase in macrophages and epithelial cells within 7 d, with evidence that macrophages had internalized particles; such changes were not evident in the second week following exposure. Likewise, peripheral blood analysis revealed significant increases in erythrocytes, hemoglobin, monocytes, and platelets within the first week after fire exposure, which were diminished 8–16 d in postexposure group.We conclude that acute exposure to forest-fire smoke elicits transient inflammatory responses, both in the airways and systemically.Whether these changes contribute to the observed increased risk of cardiovascular events requires further study.
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    Evaluating the Reliability of Assessing Home-Packed Food Items Using Digital Photographs and Dietary Log Sheets
    (2013-11) Dorman, Sandra
    Objective: To assess the reliability of manual data entry for home-packed food items by using digital photographs and dietary log sheets. Methods: Data from 60 lunches were entered by researcher A and B independently. Researcher B re-entered researcher A’s items within 1 week. Researcher B then re-entered her items 4 weeks from the initial entry point. Results: The inter-rater reliability intraclass correlation coefficient (ICC) was 0.83 for total kilocalories and ranged from 0.75–0.87 for macronutrients. The intra-rater reliability ICC was 0.92 for total kcal and ranged from 0.90–0.92 for macronutrients. The inter-rater ICCs for the 5 selected micronutrients ranged from 0.33–0.83, whereas the intra-rater ICCs for these micronutrients ranged from 0.65–0.98. Conclusions and Implications: This method of data entry is feasible and its reliability is promising for macronutrient investigations. Continued assessment of this method for investigations related to micronutrient content is recommended.