Glyphosate is the most common weed killer in the United States. Known as the active ingredient in Monsanto’s Roundup, it’s used so heavily on crops that residues show up in many foods and beverages, including beer. In February, Green America tested five of the most popular beers in the U.S. for glyphosate and aminomethylphosphonic acid (AMPA), a breakdown product of glyphosate. Contamination was detected in every sample, and the highest level measured was 3.33 ng/g (Heineken).

While this concentration is below the Environmental Protection Agency’s (EPA) acceptable levels, even low-level residues matter because pesticide exposure can build up in our bodies over time. Studies have shown that lower-dose, repeated exposures are likely more harmful than acute exposures. Other research has tied glyphosate exposure directly to cancer.

Glyphosate residues in beer alone are concerning because it’s such a popular beverage. However, beer isn’t the only food product that can expose people to glyphosate—it may also be in many other foods and drinks we consume.

Bayer, which acquired Monsanto in 2018, removed glyphosate from its home and garden products after facing tens of thousands of lawsuits filed by farmers and others exposed to glyphosate, claiming that the company didn’t warn them of the potential risk of cancer. One case brought by a farmer who used Roundup for decades and developed non-Hodgkin lymphoma (NHL) is currently being heard by the Supreme Court.

Despite these clear risks, glyphosate is still used in Monsanto’s agricultural or professional products.

And just last year, the major 2000 study that supposedly demonstrated the safety of glyphosate was retracted for being ghost-written by Monsanto scientists. In the “scathing retraction notice,” Martin van den Berg, toxicologist and co–editor-in-chief of Regulatory Toxicology and Pharmacology, wrote:

The article’s conclusions regarding the carcinogenicity of glyphosate are solely based on unpublished studies from Monsanto, which have failed to demonstrate tumorigenic potential. The handling (co) Editor-in-Chief also became aware that by the time of writing of this article in the journal, the authors did not include multiple other long-term chronic toxicity and carcinogenicity studies, that were already done at the time of writing their review in 1999.

Read the full article about beer and pesticide contamination by Emma Kriss and Todd Larsen at Food Tank.