Advisory Committee Chair
Advisory Committee Members
Russel L Griffin
Date of Award
Degree Name by School
Master of Science (MS) School of Public Health
Objectives: The current study reports the results of an ecological study regarding the association between PQ exposure and Parkinson’s disease mortality in the United States. Methods: The outcome of interest for this study was mortality due to Parkinson’s disease, obtained from CDC Wonder. The exposure of interest was PQ exposure at the county level which was obtained from the United States Geological Survey (USGS). Statistical analysis was done using the mortality data, grouped into ten-year age groups, and focused on data from 2015-2019 to account for the lag time between initial Paraquat exposure and Parkinson’s Disease mortality. A Negative Binomial model was used to describe the association between PQ exposure and PD mortality, due to the dependent variable, PD mortality, being a count dataset. A sensitivity analysis was run to see if results from the Negative Binomial differed, which would indicate if there were large amounts of missing data in the analysis. Results: A total of 3,054 counties were assessed for Paraquat use in kilograms, with 5,10, and 15 year low and high averages for each county obtained using the U.S. Geological iii Survey (USGS) Pesticide National Synthesis Project data. The results from the Negative Binomial models showed us that when comparing the RR values for the models there was not a significant association between PQ exposure and PD mortality. There was also not a significant association between PQ exposure and PD mortality as exposure levels increased. These results suggest that further studies are needed to better understand individual PQ exposure levels to further investigate an association between PQ and PD mortality. Conclusions: The current study found that there is not a statistically significant association between PQ exposure and Parkinson’s disease mortality. Previous publications have articulated this association between Paraquat exposure and Parkinson’s Disease Mortality but failed to describe the duration of the exposure variable properly. Previous publications were also limited, in that case-studies were used which could bring recall bias and small sample sizes. The implications of the findings show how the association of Paraquat, and Parkinson’s Disease Mortality might be related, but that there may be additional variables to assess for the association.
Kozuch, Alexander, "The Association Between Paraquat Exposure and Parkinson's Disease Mortality: A County-Level Ecological Study in the United States" (2022). All ETDs from UAB. 581.