Have you ever thought about the dust in your home? It turns out that this seemingly insignificant part of our lives might hold important clues to understanding why some people are more likely to develop Parkinson’s disease (PD) than others. A recent study from a group of scientists across Europe, including researchers from the University of Luxembourg, the UK Center for Ecology and Hydrology, and the University of Lübeck in Germany, suggests that household dust might be influencing the onset of Parkinson’s in people with a specific genetic mutation. And it’s not just the dust itself; it’s what’s inside the dust.
Parkinson’s disease is a brain disorder that affects movement, causing symptoms like tremors, stiffness, and difficulty with balance. It mostly affects older adults, but not everyone is equally at risk. Some people carry mutations in the LRRK2 gene, a known cause of Parkinson’s, yet many of these individuals never actually develop the disease. This leads to an interesting question: why? Researchers have long suspected that something in the environment might be playing a role, and this study provides some of the strongest evidence yet.
The study focused on analyzing household dust to see if chemicals and microbes we’re regularly exposed to might affect the development of Parkinson’s. The idea is that if you have a genetic mutation that makes you more likely to develop Parkinson’s, the things you come into contact with in your daily life, such as chemicals in dust, might push you over the edge into developing the disease.
“We know that environmental factors are important in many diseases,” said lead researcher Begoña Talavera Andújar from the University of Luxembourg. “With this study, we wanted to explore how everyday exposures might modify the risk of Parkinson’s for people carrying LRRK2 mutations.”
To do this, the researchers collected dust from the homes of four different groups of people: individuals with both Parkinson’s and the LRRK2 mutation, those who had the mutation but hadn’t developed the disease, people with Parkinson’s from unknown causes, and healthy individuals without Parkinson’s or the mutation. They also gathered blood samples to analyze the chemicals present in the participants’ bodies.
What they found was both surprising and concerning. Among the chemicals identified in household dust, two stood out as potentially harmful: Bisphenol S (BPS) and perfluorobutane sulfonic acid (PFBuS). These chemicals are replacements for older, well-known hazardous substances, like BPA (which you might recognize from water bottles labeled “BPA-free”) and PFOS, which has been linked to environmental damage. The problem is, these replacements might not be any better.
BPS, for instance, was originally introduced as a safer alternative to BPA, which is known to cause hormonal disruptions. However, this study found that BPS might actually be just as harmful, if not worse. “We saw that BPS negatively impacted the mitochondria in nerve cells,” explained Andújar. Mitochondria are often referred to as the ‘powerhouses’ of the cell because they generate the energy our cells need to function. Damage to these powerhouses can have serious consequences, particularly in the brain, where energy needs are extremely high. The researchers think that this might help to explain why mitochondrial dysfunction has such a negative impact on people with Parkinson’s disease, whose brains are already having trouble maintaining neurons.
Perfluorobutane sulfonic acid (PFBuS), another chemical flagged in the study, is used in everything from firefighting foams to food packaging. Like BPS, it was designed to replace a more toxic predecessor (PFOS), but evidence suggests it could be harmful in its own right. PFBuS is known to be incredibly persistent in the environment, meaning it doesn’t break down easily. It also has the ability to cross into the brain, where it might affect brain function and contribute to diseases like Parkinson’s.
What makes this research even more interesting is that it wasn’t just the chemicals in the dust that caught the scientists’ attention. Household dust is also full of microbes (bacteria and other microorganisms), which might play a role in either protecting us or making us more vulnerable to diseases like Parkinson’s. The study found certain bacteria in the dust that can break down harmful chemicals, but their levels were lower in the homes of people who had the LRRK2 mutation but hadn’t developed Parkinson’s. This opens up a whole new area of exploration: could our household environment, including the types of bacteria we’re exposed to, influence our risk of developing neurological diseases?
“We’ve barely scratched the surface when it comes to understanding how the environment interacts with our genes,” said Prof. Peter Bauer, another lead scientist on the study. “But these findings suggest that dust, something we often ignore, might be holding important clues to understanding why some people develop Parkinson’s and others don’t.”
The implications of this research are significant. It suggests that if we can identify harmful chemicals in our environment like BPS and PFBuS and either reduce our exposure or find safer alternatives, we might be able to lower the risk of Parkinson’s in those who are genetically predisposed. And it also suggests that our household microbes could be helping (or hindering) this process in ways we don’t yet fully understand.
Looking ahead, the researchers hope to expand their work to better understand how everyday exposures affect people with Parkinson’s. They also hope to investigate whether we can change our household environments, for example, by using safer cleaning products or encouraging the growth of beneficial microbes to protect those at risk.
It is a reminder of how little we still know about the complex ways our genes and environments interact. But it’s also a hopeful step forward. By paying attention to what’s in our homes, like in our dust, no less, we might be able to find new ways to prevent or delay the onset of devastating diseases like Parkinson’s.
As Andújar puts it, “The environment we live in is constantly influencing our health in ways we are just beginning to understand. But by exploring these hidden factors, we’re finding new opportunities to improve health and well-being.”
Citation: Talavera Andújar, B., Pereira, S. L., Busi, S. B., Usnich, T., Borsche, M., Ertan, S., Bauer, P., Rolfs, A., Hezzaz, S., Ghelfi, J., Brüggemann, N., Antony, P., Wilmes, P., Klein, C., Grünewald, A., & Schymanski, E. L. (2024). Exploring environmental modifiers of LRRK2-associated Parkinson’s disease penetrance through exposomics and metagenomics of household dust. SSRN. https://ssrn.com/abstract=4944256
