Accumulation of Fine Particles onto Three Coniferous Species

ROBERT L. BUSH, JR.: Accumulation of fine particles onto three coniferous species. There is concern that airborne contaminants generated by applying sewage sludge to land for agricultural purposes may pose significant health risks to nearby residents. Polybrominated diphenyl ethers (PBDEs) have been shown to be both a persistent class of organic chemicals in sewage sludge and to accumulate in the epicuticular wax of coniferous vegetation. Thus, local coniferous species may passively sample PBDEs and provide information related to the atmospheric dispersion of contaminants associated with land-applied sewage sludge. This work uses a controlled exposure chamber to simultaneously subject three conifer species (loblolly pine, short leaf pine and eastern red cedar) native to central North Carolina to a Rhodamine-6G aerosol, which acts as a surrogate for particle-bound PBDEs. Accumulation as a function of exposure for each species is evaluated. Findings suggest that, to normalize particle accumulation across the three species, a factor of 1.35 should be applied to cedar results reported in ng/g. Additionally, the ratio of projected area to mass is used to explain interspecies variations. This information is useful to studies that employ local vegetation as passive samplers of particle-bound contaminants such as those evaluating community exposures to land-applied sewage sludge. iv ACKNOWLEDGEMENTS This thesis is dedicated to my mother, Carol Baysinger, for giving me the opportunity to pursue my ambitions freely and for teaching me the meaning of responsibility. I truly would not be in the position I am today without her love and guidance, which she has given since I can remember. I would also like to thank my girlfriend, Nicole Vanderbosch, for her companionship and sense of humor, even in times of unintentional neglect. She has been an incredible joy in my life. I am sincerely grateful to NIEHS and NIOSH for providing financial support during my two years at UNC, and to Dr. Steve Wing and Dr. Leena Nylander-French for directing these funds. I would like to acknowledge all those in Baity Laboratory for their support and open ears, especially Maryanne Boundy for her keen review of my work and for the relaxing conversations we often shared about UNC athletics; Dr. Joe Pedit for his laboratory guidance and photographic aptitudes and Dr. David Leith for advising my work, setting an example of professionalism and sincerity, and for teaching me the importance of effective communication. Additionally, I acknowledge Dr. Mike Flynn for his membership on my …