Gram Research analysis shows that scientists have developed a new five-step strategy to test how multiple chemicals together affect human health, using real measurements from people’s blood and urine instead of testing chemicals one at a time. The approach focuses on pesticides, forever chemicals (PFAS), and metals, and could lead to safer chemical regulations that better protect people from combined exposures they encounter daily.
Scientists usually test chemicals one at a time to see if they’re safe, but people are actually exposed to many chemicals at once from food, water, and air. A major European research project called PARC developed a new way to test how mixtures of chemicals affect human health by using real data from people’s blood and urine samples. They focused on three types of chemicals: pesticides, forever chemicals (PFAS), and metals. This new approach helps governments make better decisions about protecting people from the combined effects of multiple chemicals rather than just looking at each chemical separately.
Key Statistics
A 2026 research article published in Environment International described a five-step strategy for assessing risks from chemical mixtures using biomonitoring data from people across Europe and Greenland, focusing on pesticides, PFAS, and metal(loid)s.
The PARC Real-life Mixtures project identified three chemical families and four associated health outcomes for mixture risk assessment: pesticides affecting the nervous system, PFAS affecting the immune system, and metal(loid)s affecting kidney function and neurodevelopment.
The research demonstrated that harmonizing human biomonitoring data from multiple European studies could create a consistent approach to assessing health risks from realistic chemical exposure scenarios using computer simulations.
The Quick Take
- What they studied: How to test whether multiple chemicals together cause health problems, using real measurements from people’s bodies instead of testing chemicals one at a time
- Who participated: The research reviewed biomonitoring data (measurements of chemicals in blood and urine) collected from people across Europe and Greenland in previous studies
- Key finding: Scientists created a five-step strategy to assess risks from chemical mixtures using real human exposure data, focusing on pesticides affecting the nervous system, PFAS affecting immunity, and metals affecting kidneys and brain development
- What it means for you: This approach could lead to stricter safety standards that better protect you from the combined effects of multiple chemicals you encounter daily, though it will take time for governments to fully adopt these new testing methods
The Research Details
The PARC Real-life Mixtures project developed a systematic five-step strategy for testing chemical mixtures. First, researchers identified which chemical combinations matter most for human health. Second, they gathered all available information about how much of these chemicals people are exposed to, what health effects they cause, and how the body processes them. Third, they created new methods specifically designed to test mixtures rather than single chemicals. Fourth, they built these methods into a computer tool called the MCRA toolbox that can run thousands of simulations to predict health risks. Fifth, they tested their strategy on three important chemical families using real data from people across Europe and Greenland.
This approach is different from traditional testing because it uses biomonitoring data, which means measuring actual chemicals found in people’s blood and urine samples. This shows real-world exposure rather than guessing based on laboratory studies. The researchers harmonized data from many different studies across Europe, meaning they standardized how the information was collected and organized so it could all be compared fairly.
The three chemical families they focused on were chosen because they’re common exposures with clear health effects: pesticides that can damage the nervous system, PFAS (per- and polyfluoroalkyl substances, also called forever chemicals) that can weaken immunity, and metal(loid)s like lead and cadmium that can harm kidneys and child brain development.
Traditional chemical safety testing looks at one chemical at a time, which doesn’t reflect real life. People are exposed to dozens of chemicals simultaneously from their diet, drinking water, air, and consumer products. Some chemicals may work together to cause greater harm than each would cause alone, or they might interfere with how the body processes each other. This new approach captures that complexity, making safety standards more realistic and protective.
This is a methodological framework paper rather than a traditional experimental study, so it doesn’t have a single sample size. Its strength comes from consolidating data from multiple European biomonitoring studies and being developed by major European health agencies. The approach was tested on real case studies with actual human exposure data, which increases credibility. The main limitation is that it’s a proof-of-concept, meaning the method is new and will need refinement as it’s applied to more chemicals and health outcomes.
What the Results Show
The PARC project successfully created a working strategy for assessing risks from chemical mixtures using human biomonitoring data. They demonstrated that this five-step approach could be implemented using existing tools and data from across Europe. The strategy was applied to three important chemical families: pesticides affecting the nervous system, PFAS affecting the immune system, and metal(loid)s affecting kidney function and neurodevelopment in children.
The researchers showed that by harmonizing data from different European studies, they could create a consistent picture of how much of these chemicals people are exposed to and what health risks result from those exposures. They compiled information about how these chemicals behave in the human body and what doses cause harm. This information was then used in computer simulations to predict health risks from realistic exposure scenarios.
The key innovation was demonstrating that this approach could work across multiple countries and studies with different data collection methods. By standardizing how the data was organized and analyzed, researchers could combine information from many sources to get a clearer picture of real-world chemical exposures and their health effects.
The project identified that many chemicals share common health endpoints, meaning different chemicals can cause the same type of harm. This suggests that future risk assessment should group chemicals by the health problems they cause rather than by chemical type. The researchers also found that the Monte Carlo Risk Assessment toolbox could successfully run thousands of simulations to predict how different exposure scenarios might affect health outcomes. Additionally, the work showed that European biomonitoring data, when properly organized, provides a valuable resource for understanding real human exposures to chemical mixtures.
This research builds on decades of work showing that traditional one-chemical-at-a-time testing doesn’t capture real-world health risks. Previous studies suggested that chemical mixtures might cause greater harm than individual chemicals, but there was no standardized way to test this. This project provides that standardized approach. It also aligns with growing international recognition that mixture risk assessment is necessary, building on recommendations from the European Commission and other health agencies.
This is a proof-of-concept study, meaning the methods are new and haven’t been fully tested across all possible chemical combinations. The researchers focused on only three chemical families, so the approach needs to be expanded to other chemicals. Uncertainties remain in how to predict the combined effects of chemicals when they interact in complex ways. The study relied on existing biomonitoring data, which may not capture all relevant exposures or populations. Future work will need to reduce these uncertainties and test the approach on additional chemicals and health outcomes.
The Bottom Line
Governments should consider adopting this new mixture risk assessment approach when setting safety standards for chemicals. This is a moderate-confidence recommendation because the method is new but based on solid science and real human exposure data. Individuals should be aware that their exposure to multiple chemicals is being studied more carefully now, which may lead to stricter regulations in the future. This is a high-confidence recommendation based on the direction of regulatory trends.
Policymakers and regulators should care most about this research because it directly informs how safety standards are set. Parents and pregnant women should care because the research specifically addresses how chemical mixtures affect child brain development. People who work with pesticides or live near industrial areas should care because they may have higher exposures to the chemicals studied. Everyone should care to some degree because we all encounter these chemicals in our daily lives through food and water.
Changes to safety standards based on this research will likely take 3 to 5 years to implement, as governments need time to review the methods and conduct additional studies. Health benefits from stricter standards would likely appear over 5 to 10 years as regulations reduce chemical exposures in the general population. Individual actions to reduce chemical exposure could show benefits within months to a year.
Frequently Asked Questions
Why do scientists need to test chemicals in mixtures instead of one at a time?
People are exposed to dozens of chemicals simultaneously from food, water, and air. Some chemicals may work together to cause greater harm than each would alone, or interfere with how the body processes each other. Testing only individual chemicals misses these combined effects.
What are PFAS and why are they included in this chemical mixture study?
PFAS are per- and polyfluoroalkyl substances, also called forever chemicals because they don’t break down in the environment or human body. They’re included because they’re widespread in drinking water and food, and research shows they can weaken the immune system when combined with other exposures.
How will this research change chemical safety regulations?
This new approach provides governments with a standardized method to assess risks from chemical mixtures when setting safety standards. It could lead to stricter regulations that better reflect real-world exposures and protect people from combined chemical effects rather than just individual chemicals.
What can I do to reduce my exposure to chemical mixtures?
Choose organic produce for high-pesticide foods like strawberries and spinach, use a water filter to reduce PFAS and metals, avoid non-stick cookware, and read product labels to minimize chemical exposures from personal care items and household products.
Is this research ready to be used by governments right now?
The research provides a proof-of-concept that works, but it’s still new. Governments will likely need 3 to 5 years to review the methods, conduct additional studies, and implement changes to safety standards based on this approach.
Want to Apply This Research?
- Track your dietary sources of pesticide exposure by logging produce consumption and noting whether items are organic or conventional. Measure this weekly to identify patterns in your chemical exposure from food.
- Use the app to set a goal of increasing organic produce purchases for the top three pesticide-heavy foods you eat most often, such as strawberries, spinach, and apples. Track your progress weekly and note any changes in how you feel.
- Create a long-term log of your chemical exposure sources including drinking water source, personal care products used, and dietary choices. Review this monthly to identify reduction opportunities and track changes over time as you make different choices.
This article describes a research methodology for assessing chemical mixture risks and does not constitute medical advice. Individual health risks from chemical exposure vary based on personal circumstances, genetics, and exposure levels. If you have concerns about chemical exposure or health effects, consult with a healthcare provider or toxicologist. This research is preliminary and ongoing, and safety standards based on these methods are not yet widely implemented. Always follow current regulatory guidelines for chemical safety in your region.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.