Roundup Exposure in California: What It Means for Your Health and Your Legal Rights

California is at the center of one of the most significant product liability battles in American legal history. Thousands of people across the state — farmworkers, landscapers, homeowners, groundskeepers, and others — have alleged that regular exposure to Roundup, the widely used weed killer made by Monsanto and now owned by Bayer AG, contributed to their cancer diagnoses. Billions of dollars in settlements and jury verdicts have followed.

If you or someone close to you used Roundup regularly and later received a cancer diagnosis, understanding how exposure happens, what the lawsuits allege, and what legal options exist in California is a critical first step.

This blog covers all of it in plain language.

What Is Roundup?

Roundup is a broad-spectrum herbicide that kills weeds by interfering with a specific enzyme pathway essential to plant growth. Its active ingredient is glyphosate, one of the most widely used agricultural chemicals in the world.

Monsanto introduced Roundup in 1974, and it became dominant in commercial agriculture after the company developed Roundup Ready crops — seeds genetically modified to survive glyphosate application. That combination made Roundup the go-to weed control product for large-scale farming, and its use spread far beyond agriculture into landscaping, municipal maintenance, and residential use.

In California alone, glyphosate is applied across millions of acres each year. It is used on vineyards, orchards, row crops, roadsides, parks, golf courses, residential lawns, and school grounds. For decades, Monsanto maintained that glyphosate was safe for human use when applied as directed.

That claim became the center of a legal storm.

How Californians Are Exposed to Roundup

Exposure to Roundup happens in more contexts than most people realize. The pattern of exposure — how often, how directly, and over how long a period — is one of the most important factors in evaluating a potential legal claim.

Agricultural and Farm Work

California’s agricultural sector is one of the largest in the country. Farmworkers who apply Roundup or work in fields treated with glyphosate face some of the most direct and sustained exposure. Mixing, loading, and spraying pesticides can result in skin contact, inhalation of spray drift, and incidental ingestion. Workers in vineyards, strawberry fields, orchards, and row crop operations have all been represented in Roundup litigation.

Landscaping and Groundskeeping

Professional landscapers, groundskeepers, parks maintenance crews, golf course workers, and nursery employees use Roundup regularly as part of their standard work routine. These workers may apply the product multiple times per week across entire growing seasons — often for years or decades. That cumulative exposure history is precisely what has driven many of the strongest lawsuits.

Municipal and Government Use

Cities and counties across California apply glyphosate-based herbicides along roadsides, in parks, around utility infrastructure, and on other public properties. Workers employed by municipalities and government agencies to manage vegetation have had significant occupational exposure in many cases.

Residential Homeowners and Gardeners

Roundup has been sold in hardware stores, nurseries, and home improvement retailers for decades, marketed directly to homeowners for lawn and garden care. People who used it regularly in their yards — sometimes for 10, 15, or 20 or more years — make up a significant portion of those who have pursued legal claims.

Schools, Parks, and Community Spaces

Glyphosate has been applied at schools and in parks throughout California — spaces where children, teachers, and community members spend significant time. Concerns about exposure in these settings have prompted many California counties and municipalities to restrict or ban its use in public spaces, including a well-publicized ban in Los Angeles County.

Indirect and Bystander Exposure

Exposure does not require direct contact with the product. Spray drift during agricultural application can affect nearby residents and workers. Living adjacent to treated fields, spending time in recently treated areas, or working near others who are applying the product can all result in bystander exposure over time.

What the Lawsuits Allege

The core allegation in Roundup litigation is that long-term exposure to glyphosate is linked to non-Hodgkin’s lymphoma — a cancer of the lymphatic system — and that Monsanto knew about this risk and failed to warn users adequately.

In 2015, the International Agency for Research on Cancer (IARC), a branch of the World Health Organization, classified glyphosate as “probably carcinogenic to humans.” That classification became a central reference point in Roundup litigation worldwide.

Plaintiffs have argued in court that Monsanto was aware of concerns about glyphosate’s safety well before that classification, yet continued to market the product as safe and worked actively to influence public perception and scientific discourse on the issue.

Multiple jury verdicts have supported those allegations. Edwin Hardeman, a California man who used Roundup for more than 25 years, was awarded $80 million by a federal jury after it found that Roundup played a substantial role in his stage 3 non-Hodgkin’s lymphoma diagnosis. His case was the first Roundup trial in federal court and opened the door to thousands of similar claims.

It is important to note that regulatory agencies including the U.S. Environmental Protection Agency continue to maintain that glyphosate is not likely to be carcinogenic to humans when used as directed. The scientific debate is ongoing, and the legal arguments in these cases rely on the specific evidence presented in each individual claim. No outcome in past litigation guarantees a similar result in any future case.

Non-Hodgkin’s Lymphoma: What to Know

Non-Hodgkin’s lymphoma (NHL) is a group of blood cancers that affect the lymphatic system. It develops when lymphocytes — white blood cells that are part of the immune system — grow abnormally. There are many subtypes, and the disease can range from slow-growing to aggressive.

Common symptoms include swollen lymph nodes, unexplained weight loss, fatigue, night sweats, and fever. Diagnosis is confirmed through biopsy, blood work, and imaging studies.

In Roundup lawsuits, the alleged causal link between glyphosate exposure and NHL is established through expert medical and toxicological testimony, supported by the exposed person’s documented exposure history and medical records. The strength of that connection depends on the specific facts of each case — including how long exposure occurred, how it happened, and what the individual’s overall medical history looks like.

If you have been diagnosed with non-Hodgkin’s lymphoma and you had regular or prolonged exposure to Roundup, your situation is worth discussing with an experienced personal injury attorney.

What Evidence Can Help Document Exposure

One of the most important things you can do early in a potential Roundup claim is begin documenting your exposure history. Here is what tends to matter most:

Employment and Work History

If you worked in agriculture, landscaping, groundskeeping, or any other occupation involving Roundup use, your employment records help establish where you worked, for how long, and in what capacity. Pay stubs, tax returns, W-2 forms, Social Security earnings records, and personnel files all contribute to building that picture.

Even if former employers are no longer in business, records may be recoverable through state labor agencies or former colleagues who can provide testimony about the work environment and what products were routinely applied.

Product Purchase and Use Records

Receipts, store loyalty card histories, supplier invoices, or records from landscaping suppliers and farm co-ops that document Roundup purchases can help establish that a specific product was used over a specific period. Even without receipts, the timeline can often be reconstructed through memory and corroborating witness accounts.

Witness Accounts

Family members, coworkers, supervisors, and neighbors who observed your Roundup use — or who can describe the working conditions under which you applied it — are valuable sources of corroboration. Their accounts can establish frequency, duration, and the conditions under which exposure occurred.

Medical Records and Diagnosis Documentation

Every record related to your non-Hodgkin’s lymphoma diagnosis matters — biopsy results, staging reports, oncology visit notes, treatment records, and any physician comments about contributing factors. A thorough, well-documented medical record gives your attorney the foundation to argue for damages that reflect the true scope of your illness.

Photographs and Physical Evidence

If you still have containers, packaging, or labels from the specific Roundup product you used, preserve them. Photographs of the areas where you applied the product can also help contextualize the scale and regularity of your use.

How Product Liability Claims Work in California

Roundup cases in California are typically filed as product liability claims. The legal argument is that the manufacturer placed a defective product into the market — one that was unreasonably dangerous because it lacked adequate warnings about the risk of cancer.

To build a viable claim, an attorney generally needs to establish:

That you were exposed to Roundup. This is documented through the employment, purchase, and witness evidence described above.

That you were diagnosed with non-Hodgkin’s lymphoma. This is established through your medical records.

That your exposure was a substantial contributing factor to your diagnosis. This is where expert witnesses — medical doctors and toxicologists familiar with glyphosate research — become essential. They review your exposure history and medical records and provide professional opinions about whether the evidence supports a causal connection.

That the manufacturer failed to adequately warn you of the risk. This argument draws on evidence of what Monsanto knew about the potential dangers of glyphosate and what they communicated — or failed to communicate — to users.

California’s two-year statute of limitations applies to most product liability claims, but the discovery rule can extend that window to when you discovered — or reasonably should have discovered — that Roundup may have contributed to your diagnosis. Do not assume your deadline has passed without speaking to an attorney first.

Steps to Take If You Believe Roundup Harmed You

If you used Roundup regularly and received a non-Hodgkin’s lymphoma diagnosis, these steps protect your rights right now:

Seek and maintain consistent medical care. Your treatment records are foundational to your claim. Keep all appointments, follow your oncologist’s guidance, and ensure your diagnosis and treatment history are thoroughly documented.
Write down your exposure history. Note every job where you used Roundup, the approximate years, how often you applied it, and how you came into contact with it. Include personal use at home or in community settings.
Gather any records you can access now. Employment records, purchase receipts, and medical records are easiest to collect while memories are fresh and records are readily available.
Preserve physical evidence. If you have product containers, labels, or personal protective equipment from your time using Roundup, set them aside and do not discard them.
Contact the best Roundup personal injury attorney promptly. Time limits apply, and delay can limit your options. The sooner an experienced attorney evaluates your case, the better position you are in to pursue the full compensation your situation may warrant.

Contact Walch Law for a Free Consultation

Roundup litigation is complex. It involves going up against a well-funded global company with extensive legal resources. The people who tend to do best in this process are those who act decisively, gather the right evidence early, and work with attorneys who understand how these cases are built and won.

At Walch Law, we handle Roundup exposure cases throughout California. We take the time to understand your specific exposure history, connect you with the right medical experts, and pursue every available avenue of compensation on your behalf — including medical expenses, lost income, pain and suffering, and loss of quality of life.

We handle all Roundup cases on a strict contingency fee basis. You pay nothing out of pocket, and we only collect a fee when we successfully recover compensation for you.

Contact Walch Law today for a completely free, confidential consultation. If Roundup exposure may have contributed to your cancer diagnosis, you deserve to know your options — and we are here to walk you through them.