Masters Theses

Abstract

"In this study, the ozone uptake rate for human hair and the resulting formation of volatile aldehydes and ketones were quantified. Human hair was chosen for two reasons: 1) ozone-hair chemistry may influence personal exposure to ozone and its reaction byproducts due to the proximity to the breathing zone. and 2) ozone reacts readily with human skin oils (squalene) and personal care products (fatty acids and terpenes) that may coat hair. In this preliminary study, hair samples from three ethnic groups were collected before and after washing and/or application of various personal hair care products. Hair samples were exposed to ozone in a flow through Teflon reactor. The cumulative ozone uptake was quantified by measuring the inlet and outlet ozone concentration during a 24 hour period. Organic reaction products were identified and emission rates were quantified by sampling the reactor inlet and outlet using Tenax sorption tubes and DNPH tubes followed by thermal desorption and GCMS analysis and HPLC analysis. Cumulative ozone uptake on most hair samples was surprisingly similar. On average, the ozone uptake for the washed hair samples was (0.95 ± 0.02) x 10-5 mol O3 g-1 and for unwashed hair samples was (1.30 ± 0.02) x 10-5 mol O3 g-1. The ozone reaction probability for hair fiber surfaces reduces over time and ranged from 0.02 x 10-4 for a washed sample exposed to ozone for 24 hours, to 2.1 x 10-4 for a fresh unwashed sample. The product yields of compounds associated with ozone reacting with sebum (geranyl acetone, 6 methyl 5-hepten-2-one, nonanal and decanal) were consistently higher for unwashed hair than for washed hair. While natural oils that coat hair contribute to ozone reactions on unwashed hair, ozone also appears to react with other unidentified compounds on washed hair"--Abstract, page iv.

Advisor(s)

Morrison, Glenn

Committee Member(s)

Henthorn, David
Adams, C. D. (Craig D.)

Department(s)

Civil, Architectural and Environmental Engineering

Degree Name

M.S. in Environmental Engineering

Sponsor(s)

National Science Foundation (U.S.)

Publisher

University of Missouri--Rolla

Publication Date

Summer 2007

Pagination

ix, 97 pages

Note about bibliography

Includes bibliographical references.

Rights

© 2007 Lakshmi Soujanya Pandrangi, All rights reserved.

Document Type

Thesis - Restricted Access

File Type

text

Language

English

Subject Headings

AldehydesHair -- AnalysisKetonesOzone -- Physiological effect

Thesis Number

T 9164

Print OCLC #

173522185

Electronic OCLC #

906027032

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