MS, University of Cincinnati, 2018, Medicine: Clinical and Translational Research

Abstract Background Traffic-related airborne particles have been shown to be associated with asthma morbidity. While air filtration reduces indoor aeroallergens with potential improvement in asthma symptoms, this intervention has not been extensively studied in relation to traffic particles indoors. Objective To assess the impact of a high-efficiency particle air (HEPA) cleaner on indoor particle concentrations and the resultant effect on children with asthma. Methods Forty-four children with asthma were enrolled in this double-blind, placebo-controlled crossover study. A HEPA air clear and placebo “dummy” were placed in participants' homes for four weeks, interrupted by a one-week washout period, before crossing over to the other treatment arm for four weeks. Air sampling health outcomes were completed prior to and at the end of each treatment arm. Results Indoor concentrations of traffic particles were reduced with the HEPA treatment but not with the placebo “dummy” treatment. This decrease coincided with clinically and statistically improved scores in asthma control and quality of life in those with poorly controlled asthma and inadequate quality of life at baseline. The median ACQ score decreased from 1.33 to 0.83 (p<0.05), and the median mini-AQLQ score increased from 5.00 to 5.73 (p<0.05). Conclusion Indoor concentrations of traffic particles are reduced with HEPA filtration, and this reduction is associated with improved clinical outcomes and quality of life measures in children with uncontrolled asthma.

Committee: Erin Haynes Dr.P.H. (Committee Chair); David Bernstein M.D. (Committee Member); Roman Jandarov Ph.D. (Committee Member); Tiina Reponen Ph.D. (Committee Member) Subjects: Surgery

PhD, University of Cincinnati, 2001, Medicine : Environmental Health Sciences

Lead is a toxic substance and a ubiquitous environmental contaminant. Many studies have shown its negative health effects on psychological development, neuromotor system and many other body organs. Lead was added to paint in the form of white lead to reinforce the paint and produce a tough and flexible film. It is estimated that more than 3 million tons of lead have been used in the form of lead-based paint in the U.S. during the past 100 years. As a result, about 38 million homes still contain leaded paint. For this reason, hundreds of millions of dollars have been spent in the U.S. for lead hazard control. The leaded particles aerosolized during lead hazard reduction work are a health hazard for the workers. Significant levels of leaded particles representing health hazards are aerosolized during lead abatement. Few studies regarding these aerosols have been performed. The two main goals of the research described in this dissertation were 1) to characterize the airborne leaded particles and 2) to apply the acquired knowledge to the evaluation of various lead hazard control procedures. The first goal was to investigate the fundamental characteristics of the particles aerosolized during lead abatement. An Environmental Test Chamber was designed and constructed in the Kettering building at the University of Cincinnati. Wood doors coated with lead-based paint were abated in the chamber by dry scraping, wet scraping, or dry machine sanding. The airborne particle concentration was measured with the Grimm particle size spectrometer. The size distribution of the airborne particles changed substantially with time. The airborne particle concentration for each specific size was found to decay exponentially in calm air condition. Size selective air sampling on filters and subsequent laboratory lead analysis of them showed no significant effect of particle size on the percent lead. The second goal was achieved by the following three studies. The first study was to investigate (open full item for complete abstract)

Committee: Dr. Sergey A. Grinshpun (Advisor) Subjects: Environmental Sciences

Doctor of Philosophy, The Ohio State University, 2010, Public Health

Methicillin-resistant Staphylococcus aureus (MRSA) is a significant infectious disease concern in human and veterinary healthcare settings where airborne transmission is suspected. A better understanding of sampling methods used for airborne MRSA surveillance is fundamental for accurately evaluating and successfully controlling the threat. Accordingly, we conducted laboratory and field studies to evaluate methods and risk associated with airborne MRSA. In the laboratory, Methicillin-susceptible Staphylococcus aureus (MSSA) was used as a surrogate for MRSA. Using a laboratory environmental chamber, we systematically evaluated: 1) MSSA particle size distribution, 2) efficiency of two aerosol generating methods (6-jet Collison nebulizer and Bubbler), and 3) recovery and collection of MSSA using three air sampling methods (Gelatine Filter, single-stage Impactor, and Impinger). Generation efficiencies of MSSA were evaluated using the ratio of the number concentration of airborne culturable particles to total particles. Total particle concentrations were evaluated with an aerodynamic particle sizer (TSI, Inc.) and culturable particles were evaluated using standard methods. Differences in generation efficiency were evaluated using a two sample t-test. Sampler performance was evaluated by examining: 1) loss of MSSA spiked onto the sampler over time, and 2) side-by-side measured concentration differences of airborne MSSA collection across a 4-log range aerosolized from the generator reservoir. Sampler recovery and collection comparisons were made using paired t-tests. From these laboratory studies, a pilot-scale field investigation of airborne and surface Staphylococcus spp., was performed within a veterinary hospital during periods of no known clinical Staphylococcal infections. Based on the laboratory studies we observed the aerodynamic particle size of airborne S. aureus at 0.723-0.777 micrometers. The Bubbler (1.16 x 10-4 CFU/particle) was observed to be marginally more (open full item for complete abstract)

Committee: Timothy Buckley PhD (Advisor); Armando Hoet PhD (Committee Member); Michael Pennell PhD (Committee Member); Kurt Stevenson MD (Committee Member) Subjects: Occupational Safety; Public Health; Veterinary Services