# A Nationwide Study of Environmental Risk Factors for Parkinson Disease

> **NIH NIH K01** · WASHINGTON UNIVERSITY · 2020 · $150,071

## Abstract

Abstract
Parkinson disease (PD) is the second most common neurodegenerative disease. Solvents, pesticides and
metals are suspected risk factors, but specific agents in these very broad categories remain to be identified
conclusively. Epidemiologic and animal studies together indicate that two possible candidates are the industrial
solvent trichloroethylene (TCE) and airborne manganese (Mn), a metal used as the active ingredient in some
pesticides and released during fossil fuel combustion. However, there have been few human studies on the
association between these exposures and PD. In addition, despite these exposures being common in the
environment, studies of PD and TCE have focused on occupational exposures, while the few environmental
studies of PD and airborne Mn have yielded conflicting results. The proposed K01 career award will provide
the training and resources to use “big data” and sophisticated geographic information system (GIS) techniques
to conduct a large population-based case-control study of PD and environmental exposure to TCE and
airborne Mn using previously collected nationwide data and GIS methods to examine these associations (Aims
1 and 2) and their potential interactions (Aim 3). This approach will allow us to quickly and cost-effectively
conduct a well-powered, population-based study with geographically representative cases and controls. To
complement this highly targeted approach focused on two common environmental exposures, we will apply
established methods from cancer epidemiology to the same data to identify clusters of incident PD within the
U.S. (Exploratory Aim 3). All aims will be completed using an existing large case-control study (89,790
incident PD cases and >22 million controls) of Medicare beneficiaries age >65 with detailed (9-digit zip code)
residence data and demographic data. This work will build substantially on existing literature and promises to
generate novel hypotheses on the environmental causes of an important disease known to have a strong
environmental component and only symptomatic treatment.

## Key facts

- **NIH application ID:** 9994748
- **Project number:** 5K01ES028295-03
- **Recipient organization:** WASHINGTON UNIVERSITY
- **Principal Investigator:** Susan Searles Nielsen
- **Activity code:** K01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $150,071
- **Award type:** 5
- **Project period:** 2018-09-15 → 2021-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9994748

## Citation

> US National Institutes of Health, RePORTER application 9994748, A Nationwide Study of Environmental Risk Factors for Parkinson Disease (5K01ES028295-03). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/9994748. Licensed CC0.

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