Document Type

Dissertation

Date of Degree

Spring 2012

Degree Name

PhD (Doctor of Philosophy)

Degree In

Occupational and Environmental Health

First Advisor

Patrick T. O'Shaughnessy

Abstract

Chapter II describes results from 197 rural households that were sampled over five continuous days for indoor and outdoor PM10, PM2.5, and endotoxin. Geometric mean indoor concentrations of PM10 and PM2.5 (21.2 πg m-3, 12.2 πg m-3) were larger than outdoor concentrations (19.6 πg m-3, 8.2 πg m-3; p =0.072, p<0.001). While geometric mean endotoxin levels were almost six times larger in outdoor air compared to indoor (1.47 EU m-3, 0.23 EU m-3; p <0.001). Airborne PM10 and endotoxin concentrations in a rural county were elevated compared to those previously reported in certain urban areas. Furthermore, during the harvest season, concentrations of endotoxin in ambient air approached levels that have been shown to cause decreased respiratory function in occupational workers. Chapter III evaluated the effectiveness of using Radiello passive monitors to measure hydrogen sulfide (H2S) in close proximity (<40 m) to a medium sized CAFO. A total of eight passive H2S monitors were deployed 7-14 days around a swine confinement for seven months. Additionally, a separate laboratory study was carried out to determine the monitor's H2S uptake rate. Concentrations of H2S measured near the confinement were varied and ranged from 0.6 to 95 ppb depending on the sampling period and proximity to the lagoon .The uptake rate provided by the supplier (0.096 ng ppb-1 min-1) was significantly larger (p=0.002) than the rate determined experimentally (0.062 ng ppb-1 min-1). In Chapter IV we evaluated the association between residential proximity to swine operations and childhood asthma. A metric was created to determine children's relative environmental exposure to swine CAFOs which incorporated facility size and distance and direction of the CAFO to the home. When controlling for six significant asthma risk factors, children with a larger relative environmental exposure to CAFOs had a significantly increased risk of physician-diagnosed asthma (OR=1.20, p=0.009). In stratified analysis that adjusted for a respiratory infection before the age of two years, the association between relative exposure and childhood asthma was significantly increased in children with a respiratory infection (OR=1.45, p=0.001) but not in children free from respiratory infection (OR=1.12, p=0.355).

Keywords

Air Quality, Childhood Asthma, Endotoxin, Hydrogen Sulfide, Particulate Matter, Rural Health

Pages

vii, 103 pages

Bibliography

Includes bibliographical references (pages 94-103).

Copyright

Copyright 2012 Brian Thomas Pavilonis

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