Are there toxic chemicals in your garden’s fertilizer?

You may grow your own food because you love being outdoors, getting your hands dirty, breathing in the smell of freshly dug soil, tasting fruits or vegetables that are truly fresh, or any of countless other reasons. But high on your “why I garden” list is probably this: It feels good to know where your food came from and how it was grown.

However, most gardeners aren’t aware that many types of fertilizer actually contain the toxic “forever chemicals” known as PFAS. 

How do PFAS end up in fertilizer? 

PFAS chemicals — nicknamed “forever chemicals” because they don’t break down naturally — are a growing threat to Americans’ health. They’re used in a wide range of stain-resistant clothing, nonstick pans, as well as plastics, pesticides and packaging materials. 

Because PFAS chemicals are so widely used, they often wind up in the wastewater that gets sent to sewage treatment plants. 

Now, you might be wondering how chemicals can go from sewage treatment plants to your garden, but it’s not that big of a leap. Human waste contains a lot of plant nutrients, so sewage plants often turn wastewater into fertilizer, known in the industry as “biosolids.”  

In past decades, biosolids were considered a safe and easy way to reuse wastewater. However, because most sewage plants lack the equipment to filter out PFAS, scientists are discovering that biosolids can also contain high levels of toxic chemicals. 

Do forever chemicals in fertilizer endanger your health? 

Exposure to PFAS can cause serious harm. They have been linked to a wide variety of health problems, including reproductive issues, prostate or kidney cancer, and a weakened immune system. 

Because of their longevity, PFAS can build up slowly in the soil or even in a person’s body. That means that over a long period of time, even low exposures can be dangerous. 

That’s why contaminated biosolid fertilizer is so concerning. In one Texas farm, for example, PFAS-contaminated fertilizer mysteriously killed 35 cows, as well as numerous fish. Other farms have had to be shut down after high levels of PFAS made their produce and livestock unsafe to sell. 

If contaminated fertilizer can expose cows and fish to PFAS, it stands to reason that it could expose people as well. So how do you avoid PFAS contaminated fertilizer?

How do I tell if fertilizer is safe? 

A large portion of the fertilizers on the market contain PFAS. A 2021 Sierra Club study found at least 30 different commercial fertilizers made from sewage sludge. Worse, the study found PFAS in every single one of the nine tested brands labeled as “eco” or “natural.” 

When you buy fertilizer, we recommend that you avoid all fertilizer listing biosolids as a component. If fertilizer contains “biosolids”, then it likely contains PFAS. 

Due to the prevalence of PFAS in fertilizers made from biosolids, gardeners should consider using other nutrients for their veggies and flowers, such as composting table scraps or getting manure from local farmers (as long as these farmers don’t use biosolid fertilizers). 

A problem bigger than your garden

Across the country, biosolids may have been applied on up to 20 million acres of farmland so far. If left unchecked, the rampant use of biosolids could spread PFAS into more of our land, our water and even our bodies. Gardeners can stand with farmers to call for the EPA to stop the use PFAS sludge in fertilizer.