Exploring the Latest Research on Persistent Organic Pollutants

On the 14th of May 2026, ExpoSignalz hosted its first webinar exploring the latest research on persistent organic pollutants (also known as POPs) – a type of chemical substance that can persist in our environment for a long time, with unknown effects on human health.

Titled ‘POPs and Us: Our Environment and Alzheimer’s Disease’, the webinar included talks from leading experts in the field and focused on the latest cutting-edge science.

ExpoSignalz Project Coordinator, Véronique Perrier, started by giving an overview of the project and the pressing health concern, the rising prevalence of dementia.  It is already the 7th leading cause of death in the world, with 152 million people expected to have the disease by 2050.

Véronique outlined how ExpoSignalz is investigating one of the potential causes of the disease: chemical pollutants. With research showing that occupational exposure to pesticides – one form of POPs – has a link to dementia, she demonstrated how more scientific investigation is vital to explore this link.

She summarised the three big questions ExpoSignalz is attempting to explain:

1. How does the exposome contribute to Alzheimer’s disease?
2. What are the chemical culprits, and can we identify their specific chemical signatures in our bodies?
3. Can we develop prevention strategies to mitigate the disease?

Persistent Organic Pollutants and Brain Ageing Outcomes

Dr Sophie Lefevre-Arbogast, researcher in epidemiology at Inserm in France, presented her latest paper looking at the epidemiological evidence linking POP exposure to cognitive ageing and dementia.

POPs, she explained, have several characteristics that make them particularly concerning. They are resistant to degradation and can be transported atmospherically over long distances. They also accumulate in living organisms and are known to be toxic to humans and wildlife.

POPs are regularly detected in our brains during autopsies, and there is experimental evidence of neurotoxicity and adverse neurodevelopmental outcomes from exposure. The case to investigate their role in the development of dementia was clear.

Using data from the long-term ‘Three-City Study’ in France, Sophie and her team investigated various brain ageing outcomes – including the incident rates of dementia, signs of cognitive decline and brain atrophy. They then checked for 28 different POPs in participants of the study to see if there were any links. Whilst they found a strong rationale for the role of environmental pollutants in our lifelong brain health, her studies on POP exposure and its impact on our brains remain inconclusive.

She highlighted the need for new studies considering different exposure windows (such as childhood and adulthood), and looking at population-specific vulnerabilities. In her study, those that had the APOE-4 allele seemed particularly vulnerable. She also made the case for expanding research into other POP types and non-persistent contaminants (such as currently used pesticides).

Genes and Environmental Interaction

Dr Jason Richardson then gave an overview of his latest research, exploring if POPs can induce ‘neuronal hyperexcitability’ (uncontrolled firing of our brain cells) and accelerate Alzheimer’s pathology.

He explained that genetics alone cannot explain the prevalence of late-onset Alzheimer’s disease, and reiterated that the exposome – including our lifestyle, social circumstances, physical and chemical exposures – could complete the picture of why dementia is more common in older age.

Overall, Jason concluded that environmental exposure is a significant, modifiable contributor to Alzheimer’s risk. Genes and environmental interaction can show specific population vulnerabilities, which will require broad, multi-ethnic, multi-cohort research. His investigations have provided some clear targets for prevention and treatment options and provide the evidence base for population-scale prevention.

Complex Mixtures of Chemicals

Finally, Professor Xavier Comoul from the Université Paris Cité presented his research exploring how POPs can be linked to the development of Alzheimer’s disease mechanistically.

There is an increasing ‘chemical burden’ all around us – air pollutants, pesticides, solvents, plastics and metals. Today, we mostly deal with the consequences of exposure, but to prevent it, we will need to understand the causes, too.

Xavier explained that there is difficulty in researching this. There is a huge amount of complexity in the real-life mixtures of chemicals we’re exposed to, and a need for a more holistic exposure assessment in research. POPs usually affect us through chronic, low-dose exposure from our food and environment, with potential long-term neurotoxicity. This adds to the complexity. He highlighted several mechanistic pathways linking POPs to neurodegeneration. and discussed how specific receptors in our bodies can be activated by multiple POPs.

Concluding, Xavier explained that environmental pollutants are likely contributors to neurodegenerative trajectories, with POPs targeting convergent ‘biological pathways’ in our bodies. He suggested that both experimental and epidemiological studies were equally important, and outlined how ExpoSignalz and wider exposomics and systems toxicology research will all help reshape the field.

Conclusions

There were a few overall key takeaways from the webinar, which are:

1. Patients with the APOE4 allele seem to be more sensitive to pesticides, particularly POPs, with a stronger link to cognitive decline. This is a new area of gene and environment interaction.
2. There is a convergence of in vitro, in-cellule, and in vivo models to develop actionable prevention targets for precision medicine.
3. The brain is an organ susceptible to POPs, with different developmental windows of vulnerability, particularly for children and older people.

Interested in anything discussed in this webinar? Watch the recording below.