Pesticides and Autoimmune Risk: What a New RA Study Means for Roundup Users

For years, a cloud of concern has been growing over the long-term health effects of chemical pesticides. This issue has been brought into sharp focus by the massive litigation surrounding Roundup and its link to non-Hodgkin lymphoma. Now, new scientific research is adding another layer to the conversation, this time exploring a potential connection between certain pesticides and a debilitating autoimmune disease: rheumatoid arthritis (RA).

A new study accepted for publication in Arthritis & Rheumatology on July 16, 2025, has found associations between exposure to specific agricultural pesticides and an increased risk of developing RA. While this research did not find a link between glyphosate (the active ingredient in Roundup) and RA, its findings are significant for anyone exposed to agricultural or residential chemicals. It highlights the critical importance of understanding exactly what you were exposed to and how to document your health history—principles that are at the very heart of any successful product liability claim.

At Walch Law, we have been at the forefront of helping Californians injured by dangerous products for over 45 years.

Key Takeaways from the New Pesticide and RA Study

The study investigated pesticide use and the risk of developing rheumatoid arthritis among more than 22,000 female spouses of licensed pesticide applicators in the Agricultural Health Study. It is important to note this is an observational study, which means it identifies associations or correlations, not definitive causes.

Here are the key takeaways:

Insecticides and Fungicides Showed Associations: The researchers found that women who reported using certain insecticides had a higher risk of developing RA. These included older organochlorine insecticides like DDT and lindane, as well as some organophosphates and carbamates. Use of certain fungicides, like captan and metalaxyl, was also associated with an increased RA risk.
Herbicides Were Generally Not Associated with RA: For the most part, the study did not find a link between using herbicides (weedkillers) and developing RA. One specific herbicide, metribuzin, was an exception, showing a possible association.
Roundup (Glyphosate) Was Not Implicated: It is critical to understand that this study did not report an association between glyphosate, the active ingredient in Roundup, and rheumatoid arthritis.
Limitations of the Study: As with any scientific research, it’s important to recognize the limitations. The findings are based on self-reported pesticide use, and while researchers adjusted for factors like smoking and age, other unknown variables could have influenced the results. This study identifies a potential link that warrants more research; it does not prove that these pesticides cause RA.

What This Means for California Roundup Users

This study adds to a growing body of evidence suggesting that long-term chemical exposure can have serious, unintended health consequences. For Californians who have used Roundup, the message is clear: precision matters.

The current Roundup litigation is focused exclusively on one diagnosis: non-Hodgkin lymphoma (NHL). If you were diagnosed with RA, this study does not create a pathway for a Roundup claim. However, it reinforces several core principles that are vital for anyone with a potential toxic exposure case:

Your Specific Diagnosis is Everything: Your legal options depend entirely on your medical diagnosis. For Roundup claims, that diagnosis must be a subtype of NHL. For other chemical exposures, a different diagnosis might be relevant, but it must be supported by medical and scientific evidence.
Product Identification is Non-Negotiable: This study looked at dozens of different chemicals. It demonstrates that you cannot simply say you were “exposed to pesticides.” You must identify the specific product(s) you used. Was it Roundup (glyphosate), a different herbicide, an insecticide, or a fungicide?
Documentation is Your Most Powerful Tool: A successful claim requires a detailed history of both your chemical exposure and your medical journey.

Legal Angles: Roundup (NHL) vs. Other Pesticide Claims

The legal path for a Roundup NHL victim is well-established, with thousands of cases already moving through the courts. A claim for a different condition, like rheumatoid arthritis linked to a different pesticide, would be a new and separate legal battle. However, the underlying legal theory would be similar: product liability.

A product liability lawsuit argues that a manufacturer is responsible for injuries caused by its product. This can be based on:

Design Defect: The product’s chemical formulation was inherently unsafe for its intended use.
Failure to Warn: The manufacturer knew or should have known about the health risks associated with its product but failed to provide adequate warnings to users.

To build any such case, you and your legal team must gather extensive evidence, including purchase receipts, lot numbers, employer records (for landscapers or farmworkers), and photos of the products used. If your exposure occurred while working for a public agency (e.g., a city parks department), you may also have a claim against that government entity, which has a strict 6-month deadline in California.

Practical Tips for Documenting Your Exposure

If you have been diagnosed with a serious illness and believe it may be linked to pesticide use of any kind, start documenting everything immediately.

Create an Exposure Diary: Write down every detail you can remember.
- Products: What specific brands did you use? (Roundup, Spectracide, etc.)
- Duration: Over how many years did you use them?
- Frequency: How often did you apply them? (Weekly, monthly, seasonally?)
- Method: Did you use a backpack sprayer, a handheld spray bottle, or a hose-end applicator?
- PPE: Did you wear gloves, long sleeves, or a mask? Be honest.
- Locations: Where did you spray? (Yard, garden, farm, commercial properties?)
Gather Medical Records: Obtain copies of all your medical records, especially pathology reports that confirm your specific diagnosis.
Find Witnesses: If you worked with others, like on a landscaping crew or farm, their statements can help corroborate your exposure history.

Frequently Asked Questions (FAQ)

1. Does this new study prove that Roundup causes rheumatoid arthritis?
No, it does not. The study did not find an association between glyphosate (Roundup) and RA. The study found associations between other specific pesticides (mostly insecticides and fungicides) and RA.

2. I have rheumatoid arthritis, but I also used Roundup for many years. Do I have a case?
Based on the current science, there is not an established legal pathway for a Roundup claim based on an RA diagnosis. The litigation is focused on non-Hodgkin lymphoma.

3. I’m a professional landscaper. How can I document my exposure?
Gather employment records, pay stubs, work logs, and statements from co-workers or supervisors. If your employer kept records of chemical purchases, those are invaluable.

4. What diagnoses qualify for the current Roundup settlement programs?
The current Roundup litigation is focused on individuals who have been diagnosed with non-Hodgkin lymphoma or one of its subtypes after significant exposure to Roundup.

5. If I was exposed at work, can I bring both a workers’ compensation claim and a product liability lawsuit?
Yes, in many cases. A workers’ compensation claim is filed against your employer for an injury that happened on the job. A product liability lawsuit is filed against the manufacturer of the dangerous product. These are two separate claims that can often be pursued at the same time.

6. How long do I have to file a claim?
This is a complex legal question. Generally, California has a two-year statute of limitations for personal injury claims, which starts from the date you knew or should have known that your injury was caused by the exposure. The best Roundup injury attorney can help determine the specific deadline for your case.

Get Clarity on Your Legal Options– Experienced California Roundup Law Firm

The connection between chemical pesticides and chronic disease is a rapidly evolving area of science and law. Whether you have been diagnosed with non-Hodgkin lymphoma after using Roundup or have another serious health condition you believe is linked to chemical exposure, you need an experienced legal team to help you understand your rights.

The family at Walch Law is here to help you navigate this complex process. We offer free, confidential consultations to assess your case and explain your options. We handle all product liability cases on a contingency fee basis, which means you pay absolutely nothing unless and until we win a recovery for you. Contact us today to get the answers and the help you deserve.