# Characterizing the link between multiple environmental exposures and Parkinsons disease exacerbation

> **NIH NIH R01** · HARVARD UNIVERSITY D/B/A HARVARD SCHOOL OF PUBLIC HEALTH · 2024 · $575,554

## Abstract

Project Summary/Abstract
Parkinson's disease (PD) is one of the fastest growing neurological disorders in the US. The number of people
with PD is projected to increase to over 12 million by 2030, with an economic burden surpassing $79 billion by
2037. The progression of pathogenesis is paralleled by an exacerbation in symptom severity, which underlies
the need for hospitalization. If environmental exposures exacerbate PD symptoms, then days (acute effects) or
years (chronic effects) of higher exposure should result in higher rates of hospitalizations. There is evidence that:
1) air pollution might negatively impact the central nervous system via oxidative stress and neuroinflammation;
2) temperature might increase the risk of PD due to thermoregulatory disorders or medication use; and 3) access
to green spaces might protect against PD exacerbation. While few studies have examined the association
between air pollution, temperature, and greenness and PD, the specific PM2.5 components contributing to PD
are unknown, the effects of weather parameters on PD are poorly understood, and there is a lack of evidence
on how to identify individuals who are at highest risk for adverse PD outcomes. To date, no study has estimated
the link between simultaneous exposure to air pollution, weather, and greenness and PD exacerbation in a
nationally representative population using rigorous statistical methods for confounding adjustment. Our goal is
to conduct national studies to identify the multiple modifiable environmental factors that contribute to PD
exacerbation and increased PD vulnerability. Specifically, in Aim 1 we will conduct national studies to estimate
the chronic effects of 1a) PM2.5, NO2, ozone, PM2.5 components, 1b) greenness, 1c) simultaneous multiple
exposures and their interactions on: a) incidence of first PD hospitalization and b) re-hospitalizations, as
surrogate for accelerated disease severity. In Aim 2 we will estimate the acute effects of 2a) PM2.5, NO2, ozone,
2b) greenness, 2c) mean daily temperature and heat index, 3c) simultaneous multiple exposures on PD
hospitalizations. In both Aims 1 and 2 in main analysis we will use Medicare Part A (inpatient hospitalizations)
for the full study period (2000-2020), and we will then conduct sensitivity analyses using Part A linked to B
(outpatient) and D (medication use) claims to increase rigor in identifying PD cases. In Aim 3 we will develop
and apply machine learning methods and existing methods to identify subpopulations at increased risk. In Aim
4, to ensure transparency and reproducibility, we will develop peer-reviewed, open-source, and computationally
efficient software so other investigators may implement our methods. In summary, findings of this study will
provide evidence on the link between simultaneous environmental exposures and PD exacerbation with the
highest possible scientific rigor, and will identify multiple modifiable risk and protective factors that lead to
increased vulnerab...

## Key facts

- **NIH application ID:** 10898715
- **Project number:** 5R01ES034373-03
- **Recipient organization:** HARVARD UNIVERSITY D/B/A HARVARD SCHOOL OF PUBLIC HEALTH
- **Principal Investigator:** Danielle Braun
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $575,554
- **Award type:** 5
- **Project period:** 2022-09-20 → 2027-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10898715

## Citation

> US National Institutes of Health, RePORTER application 10898715, Characterizing the link between multiple environmental exposures and Parkinsons disease exacerbation (5R01ES034373-03). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10898715. Licensed CC0.

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