The different lifestyles, occupations and biology of men and women could mean that pesticides affect them in different ways. Margreet van der Burg shares evidence from SPRINT that highlights some of these differences.

When you think of pesticides, you may not immediately think of gender inequality issues. However, more and more scientists are recognising that many environmental health risks affect men and women in different ways – either because of their gender (social roles, norms and power relations) or because of their sex (biological characteristics, such as hormonal and reproductive systems).

In the case of potentially toxic pesticides, understanding differences in how they affect males and females could lead to more comprehensive risk assessments of pesticides.

Moreover, they could also enable more effective health protection measures. Studies have linked pesticides to illnesses including cancer and Parkinson’s disease.  They have also been linked to disruption of the hormonal system. This is key given that the hormonal system is not the same in male and female bodies.

Currently, safety standards to protect people from pesticides’ possible risks, such as the acceptable daily limit (ADI – an intake limit set by regulators) are designed to protect the population as a whole. They do not differentiate between different groups of people, some of whom may be more at risk than others.

To help understand the potential risks of pesticides, the SPRINT research project measured pesticides residues in the environment, in homes, in our food, and in human and animal bodies. We also explored some of their possible effects on health.

Importantly, we separated out results for males and females.  Here are some of our key findings.

How do gender roles in farming affect pesticide exposure?

The scale and nature of exposure are key factors in determining whether pesticides pose a risk to you or not.  That is: how likely are you to encounter pesticides, how many, in what quantities and how often? The higher the exposure, the higher the potential risk.

In farming, gender roles often shape who performs which tasks. Previous studies show that men are often more likely than women to spray pesticides.

In one SPRINT test, we found that male farmers working on conventional farms in Europe had the highest numbers and levels of pesticide residues on silicone wristbands that picked up residues from their environment. This was compared with female farmers, organic farmers, and non-farmers. These results suggest that male non-organic farmers had the most direct contact with pesticide mixtures.

However, men and women’s roles can differ depending on the type of farm (e.g. organic vs. non-organic), the farm’s size, and the country. We recommend that future research looks into this variation in more detail, as well as changes in gender roles that influence  farmers’ pesticide exposure. Gendered divisions of labour are changing on many farms and in many places, with more women taking on tasks traditionally performed by men. 

It is also important to look into broader structural factors that shape gendered patterns of pesticide exposure in farming, including differences in access to training, the use of protective equipment and decision-making power.

Pesticide residues in the home: gender implications of exposure

While it is concerning that male farmers may be exposed to the highest levels of pesticide residues in Europe, it is not necessarily surprising. What may be more remarkable are SPRINT’s findings in the home.

SPRINT found high numbers of pesticide residues in farmers’ household dust – many more than out on the field. The concentrations were much lower than those on farmland, but the ‘mixtures effect’ (where pesticides interact with one another to have unexpected effects) is a potential concern here.

Total number of different pesticides detected in samples of air, crops, sediment, soil, water and dust collected from 10 European countries. Source: Silva et al (2023)

While all household members could be affected by these residues, women tend to do more domestic work than men and take on more care responsibilities. This may mean women spend more time indoors, increasing their exposure to pesticide residues in household dust.  

Certain life stages and health conditions, such as early childhood, pregnancy, older age or chronic illness, also potentially put people at greater risk from exposure to multiple pesticides in the home.

We also found that homes that are regularly cleaned tend to contain fewer pesticide residues in dust.  Hygiene practices, such as removing shoes and work clothing before entering the home by (mostly male) farmers, and household cleaning are key.

That said, exposure prevention should not rely solely on domestic surveillance. The primary responsibility lies with effective regulation, safer pesticide use practices and broader risk reduction strategies.

Among non-farmers, our research indicates that women have more direct contact with pesticides in their daily surroundings than men, as shown by our silicone wristband study. More research is needed to understand these findings and their potential health implications, but they may reflect differences in occupations, consumption habits or time spent in particular environments.

It is unclear how our wristband results translate into uptake of pesticides by the body. When we tested blood, urine and faeces for pesticide residues, we did not see clear differences between men and women. This may be because diet drives the intake of pesticides.

However, while the methods used do not show gender differences in uptake, the combined evidence suggests that exposure routes can vary between men and women.

Biological differences affect pesticide risks

So far, we have considered how exposure is affected by gender. We will now turn to the influence of biological sex on how pesticides affect the body after exposure has occurred, drawing on our tests with mice and rats.

In one of our recent studies (now under peer review), we gave mice drinking water containing glyphosate, the world’s most commonly used herbicide. The results were surprising. Even at very low, environmentally relevant exposure levels, the male mice started behaving differently in social situations.

When we introduced a new mouse into their space, they were noticeably less interested in the newcomer. Normally, mice are curious to meet newcomers. This is even the case for mice kept in a laboratory. 

The female mice, on the other hand, seemed mostly unaffected by glyphosate at these low levels. It was only at the highest dose that they showed any clear change, moving around less than usual.

These early findings hint at the influence of the gut microbiome on the brain and behaviour. The contrasts in behaviour may be because the pesticide affected different bacterial species in the gut of males than in females, with potential differential knock-on effects on the brain and body.

Further tests on rats revealed adverse effects in males that were not observed in females. For example, glyphosate and acetamiprid affected the circulatory systems of males, tebuconazole harmed their alimentary (nourishment) system and all three of these pesticides affected male reproductive systems.

Future research needs to investigate these sex-differentiated patterns in more depth to better understand why the pesticides had these effects.

Also critical is to investigate whether these sex-specific effects are seen in other species including, of course, humans, but also farm animals. This remains unclear.

Most farm animals (notably cows, sheep, pigs and chickens) are female. They typically live in, or alongside, pesticide-sprayed fields and consume feed that contains pesticide residues. This raises questions about sex-specific exposure and effects in livestock.

We know that pesticides can affect the hormonal system, and it may be hormonal responses that drove the different effects in the mice and rats in our experiments.

Also important is to consider that changes in hormonal status (e.g. puberty, pregnancy, menopause, or medical hormone therapy) may also influence the effects of pesticides. In human research, this also implies that we need to acknowledge that binary male/female categories do not fully capture biological variation.

Gender awareness in research: lessons from SPRINT for other projects

Integrating a meaningful gender dimension in a research project is not just about disaggregating data by sex.

In SPRINT, we established a Gender Committee, including an experienced gender scholar, to ensure that sex and gender considerations were embedded across the project.

The Committee organised training sessions, conducted internal surveys, and worked closely with each Work Package to identify where and how gender/sex analysis could strengthen research design, data interpretation and policy recommendations.

For future research projects, we recommend:

• Include gender expertise from the project design stage.
• Allocate sufficient time and resources for integrating sex and gender considerations across all work areas, both for the gender committee and for project members.
• Allocate sufficient resources to collect sex-disaggregated data for all species involved (and provided this complies with 3R principles for animal tests, notably minimising the number of animals used).
• Consider whether and how any observed patterns relate to sex or gender issues by examining potential correlations with behavioural and wider social patterns more closely.
• Ensure gender experts are fully embedded in meetings, training and communication processes.

The SPRINT Gender Committee’s work appeared to be effective. A survey among the consortium members at the end of the project showed a considerable increase of gender awareness, knowledge, and capabilities.

SPRINT’s findings suggest that pesticide exposure and health risks cannot be fully understood through a neutral lens that disregards sex and gender. Exposure pathways are shaped by gender roles, while biological responses may vary by sex and hormonal issues.

Integrating these dimensions into research and risk assessment does not complicate science unnecessarily, it makes policies and protection measures more accurate and more equitable.

Dr. Margreet van der Burg is Chair of the SPRINT Gender Committee and a Senior Lecturer/Researcher in Intersectional Gender Studies/History related to Food, Agricultural and Rural Research and Development at Wageningen University.

Many thanks to Antonia Riedel, Eoin Gunnigle, Paul Scheepers, Paul Nathanail, Vera Silva and Michelle Kilfoyle for their valuable contributions to this blog.

Want to know more?

• Keep a close eye on our publications page for new research papers on the effects of pesticides on male and female mice.
• SPRINT Report: Exposure to PPPs by gender in farmers, neighbours and consumers (2025) 
• SPRINT Report on the gender-specific analysis addressing distinct toxicological effects patterns of pesticides mixtures (2025) Available upon request: This email address is being protected from spambots. You need JavaScript enabled to view it.
• SPRINT Report: Gender insights into the EU-SPRINT project (2022)
• Conference presentation: Pesticide exposure and the microbiota-gut-brain axis, presented by Eoin Gunnigle. Discusses some of the effects of pesticides on male mice.  
• Poster (2025): The Gender⁺ Dimension in SPRINT

You may have heard that some pesticides can disrupt the gut microbiome. In this post, Maaike Gerritse shares findings from the SPRINT project that show how pesticides affect this delicate ecosystem. She also describes the first ever evidence that pesticides can change the microbiome in your nose that protects you from disease.

Back in 2022, I explained why our research project, SPRINT, was so keen to explore the links between pesticides and the gut microbiome in my blog: How and why SPRINT are studying microbiomes.

A microbiome is the combination of millions to trillions of bacteria, fungi and other micro-organisms that live together. A healthy microbiome in your gut, with ‘good’ bacteria, helps protect you from diseases including cancer, obesity, coronary heart disease, diabetes and dementia. Not only that, but it helps you digest fibre, provides certain vitamins, and keeps stomach bugs at bay by keeping your gut occupied: no space for ‘bad guys’.

Fast forward to today, we have now completed our microbiome investigations on SPRINT. You will be able to learn more about many of these in forthcoming peer-review journal papers (anticipated in 2026).

For now, I am very pleased to give you a preview of some of our key findings. As these results have not yet been peer-reviewed, do interpret with some caution. We will list journal papers as they are published on our website – keep an eye out for them there.

Which pesticides affect the gut microbiome?

Our researchers investigated the gut microbiome by extracting bacterial DNA from faecal samples. Based on this DNA, we could see which bacteria are present in the gut microbiome.

We also looked at which pesticides enter the body from our diets and environment by analysing the blood, faeces, and urine of hundreds of volunteers.

From this, we could link eight pesticides or classes of pesticide with small changes in the composition of the gut microbiome. These substances were: pyrethroids, glyphosate, metalaxyl, hexachlorobenzene, pirimiphos-methyl, propiconazole, DDT and chlorpyrifos.

‘Composition’ refers to which bacterial species are present in the gut, and how abundant they are relative to other species. Importantly, four of these pesticides (propiconazole, pirimiphos-methyl, metalaxyl, and hexachlorobenzene) had not been linked to the gut microbiome before. This suggests that more pesticides may be connected with changes in the gut microbiome than previously thought.

The effects of higher pesticide levels on the gut microbiome

As part of SPRINT, we asked volunteers to wear silicone wristbands that absorb pesticides from the environment, and not from their diet, to learn more about which chemicals they encounter in everyday life.

We found that people exposed to certain pesticides have a slightly different gut microbiome than people exposed to a very low number or a low concentration of pesticides.

Our test results suggest that mixtures of pesticides may have more impact on the gut microbiome than pesticides that are tested individually. This is an important finding since we are usually exposed to mixtures of pesticide residues rather than single compounds.

Which gut microbes are affected by pesticides?

A higher pesticide burden (i.e. total pesticide numbers and concentrations) was associated with a loss of some bacteria, including beneficial bacteria. For example, Bifidobacterium was reduced with a higher total pesticide burden.

Research shows that Bifidobacteria reduce inflammation and are linked to a lower risk of gastrointestinal diseases, allergies, metabolic disorders and depression.  

Bacteroides, a dominant group of bacteria in the gut, was also reduced with higher concentrations of pesticide mixtures. Bacteroides help provide energy for the gut and prevent inflammation.

The population of Akkermansia, a group of bacteria associated with metabolic health and a lower body weight, was also lower at higher concentrations of multiple pesticides.

These findings indicate that pesticide-associated changes in the gut microbiome might have consequences for human health.

The nasal microbiome?

Some of you might know that SPRINT also investigated the microbiome in the nose. It is not only the gut microbiome that plays a role in human health; the nasal microbiome also supports your immune system as well as your ability to smell.

An imbalance in the respiratory microbiome is suspected to be a risk factor in respiratory infections, such as asthma, but also Parkinson’s disease and Alzheimer’s disease.

The effect of pesticides on the nasal microbiome has not previously been studied.  The respiratory microbiome has many parts. For example, the microbiome of the nose is very different to the microbiome in your throat, mouth and lungs. Our researchers were the first research team to find out that pesticide exposure can be linked to changes in the nasal microbiome.

We discovered an association between the total number of pesticides detected on silicone wristbands worn for one week and changes in nasal microbiome composition – as detected by swabbing the nostrils of our participants and extracting bacterial DNA from the swab.

The pesticides on wristbands mostly came from the participants’ environments, rather than their diets. This suggests that the effects on the nasal microbiome may be due to inhalation of pesticides in the air or dust.

Could pesticides affect your mental health and behaviour?

The gut microbiome is increasingly recognised as an important influence on brain function and behaviour, with good gut health linked to improved mental wellbeing.

However, exposure to pesticides, and other chemicals in the environment may influence the relationship between the gut and the brain by altering the presence or balance of microbes that are involved with communications between the two organs.

In SPRINT, we investigated the effects of glyphosate — a commonly used herbicide — on the gut microbiome and behaviour in mice

Normally, mice are curious to meet newcomers. This is even the case for mice kept in a laboratory. We found that male mice had disrupted social behaviour when we exposed them to glyphosate at low levels, i.e., at the ‘acceptable daily intake’ (ADI) which is the limit set by regulators.

Specifically, the mice interacted less with a new mouse that was introduced to the lab setting, compared with mice in the experiment that were not exposed to glyphosate.

In another test, male mice showed some signs of increased anxiety-like behaviour following glyphosate exposure. Female mice showed fewer behavioural changes (to find out more about sex differences, look out for our upcoming blog on pesticides, sex and gender).

These effects appear to be linked to changes in the gut microbiome. Glyphosate exposure corresponded with subtle but measurable shifts in the composition of gut microbes in both sexes.

When we transferred microbiota from glyphosate-exposed male mice to mice that we did not expose to glyphosate, the recipient mice developed the same social behavioural trait as the glyphosate-exposed mice.

This demonstrates that the microbiota changes were sufficient to drive this effect. Anxiety-like behaviour, however, was not transferable. This suggests that different processes are involved in anxiety and social behaviour. 

Many studies, including ours, show that glyphosate is associated with small changes in the human gut microbiome. However, more research is needed to see whether similar effects on behaviour occur in humans. These findings raise important questions about how every day, low-dose exposure to widely used herbicides may influence our behaviour through the gut microbiome.

What do these findings mean for your health?

These changes to microbiomes may have consequences for your health. Regulators have many safety considerations when deciding whether to approve a pesticide for the market. The effects of pesticides on the microbiome might be an interesting new factor for them to consider.

However, while we know that the gut microbiome is very important for health, many other factors can interfere with its composition, such as your age, diet, exercise, sleep and medication use.

If you want to protect your gut microbiome, the most important thing is to eat a fibre-rich diet with many fruits and vegetables and consider buying organic products when you can.

To further support your gut health, you should limit your sugar consumption, stay well‑hydrated, get enough sleep, and exercise regularly.

What about your nose? Just as for the gut microbiome, there are many factors that influence the nasal microbiome, and many more studies are needed to better understand how it works.

However, it is possible that regularly cleaning and airing your home may help protect the nasal microbiome from pesticides in your environment. SPRINT has also shown that pesticide residues accumulate in household dust. In our silicone wristband study, we found that study participants who reported regularly cleaning their homes and opening their windows were less likely to have direct contact with pesticides.

Want to know more?

Keep a close eye on our publications page for new research papers on pesticides and the microbiome.

Webinar: Pesticides and Human Gut Health, presented by Maaike Gerritse and Milla Brandão Gois.

Research paper: Pesticide exposure and the microbiota-gut-brain axis. By: Matsuzaki, R., Gunnigle, E., Geissen, V., Clarke, G., Nagpal, J., Cryan, J F.,  in The ISME Journal (2023). 

Research summary: Linking synthetic pesticide exposure to the gut microbiota and brain functioning. 

Conference presentation: Pesticide exposure and the microbiota-gut-brain axis, presented by Eoin Gunnigle.

Thank you to Eoin Gunnigle and Paul Scheepers for their valuable contributions to this blog.