Masters Theses


"Estrogens are a broad class of compounds which exert many physiological effects. In addition to gonadal and peripheral endogenous estrogen production, humans can be exposed to exogenous estrogenic compounds (xenoestrogens) from medicinal, dietary and environmental sources. These compounds can exert effects similar to that of 17β- estradiol (E2) through estrogen receptor (ER) mediated mechanisms, or via ER- independent pathways. One such compound is the triazine herbicide atrazine. A number of studies have implicated atrazine as an endocrine disrupting chemical (EDC). An ecologic study of breast cancer incidence and atrazine exposure in Missouri counties was conducted for the combined years of 1996-2002. The objective of this study was to determine if breast cancer incidence rates were associated with atrazine exposure in Missouri counties. Atrazine detections in public drinking water sources and a surrogate measure of combined acres of corn and sorghum planted were used to determine which of Missouri’s 115 counties could be classified as having high atrazine exposure and which counties had the least atrazine exposure. Overall, nineteen counties were classified as high, and twenty-five were classified as low in exposure to atrazine. In the linear regression model, the atrazine indicator was not statistically significant in either regression equation (p = 0.167 for all stages of breast cancer and p = 0.371 for invasive breast cancer). The limitations of ecologic studies and the need for increased understanding of atrazine’s biological mechanisms are reasons that further studies are necessary"--Abstract, page iv.


Huang, Yue-wern

Committee Member(s)

Aronstam, Robert
Gadbury, Gary L.


Biological Sciences

Degree Name

M.S. in Applied and Environmental Biology


University of Missouri--Rolla

Publication Date

Summer 2006

Journal article titles appearing in thesis/dissertation

  • Human exposure to medicinal, dietary, and environmental estrogens
  • Atrazine exposure and breast cancer incidence: an ecologic study of Missouri counties


ix, 61 pages

Note about bibliography

Includes bibliographical references.

Geographic Coverage



© 2006 Loretta Dunn Hunter, All rights reserved.

Document Type

Thesis - Restricted Access

File Type




Subject Headings

Atrazine -- Environmental aspects -- Missouri
Breast -- Cancer -- Missouri
Estrogen -- Health aspects

Thesis Number

T 8916

Print OCLC #


Link to Catalog Record

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