A family of chemicals found in a wide range of every day products is becoming a challenging new problem
Remember in the 1970s when tens of thousands of dairy cattle in Michigan were destroyed as a result of the accidental introduction of a fire-retardant chemical, polybrominated biphenyls (PBBs), into feed products? This tragic and unfortunate event significantly affected livestock agriculture and farmers livelihood in Michigan. On the other hand, it was fortunate that the source of the contamination was tracked to a feed source and, therefore, relatively easy to “contain and fix.”
Fast forward 40 years and insert PFAS (per- and poly-fluorinated alkyl substances) instead of PBBs. However, there is a key difference. PFAS is a group of chemicals widely used in commerce since the 1940s across the United States. Moreover, instead of being directly added to a finite food source, it may be introduced into livestock agriculture through several common practices at many farms.
Like PBBs in the 1970s, PFAS is the newest “emerging contaminant.” We know it is out there but have not yet figured out the risk associated with it. If you have not heard of PFAS, it is likely that you will soon as the investigation of PFAS in the environment, and potentially into food products, increases.
Recently, there has been a focus on PFAS impacts to our food supply, including dairy farms. In the extreme, PFAS impacts have the potential to put a dairy out of business. So, what does a dairy farmer need to know about these chemicals?
What Are PFAS?
PFAS (per- and poly-fluorinated alkyl substances) are a class of man-made chemicals that were created in the 1940s. They are a family of over 5,000 chemicals characterized by a series of chemical bonds between carbon and fluorine atoms, which is one of the strongest bonds in nature. The result is that these chemicals are fantastic at repelling oil and water, resisting heat, and reducing friction (making items “non-stick”). The current focus is mostly on two specific PFAS compounds, PFOA (perfluorooctanoic acid) and PFOS (perfluorooctanesulfonic acid).
Because of these helpful properties, PFAS are used in numerous commercial products. Look around your house and you will likely find PFAS in your carpet, furniture, raincoat, boots, pots and pans, and even your dental floss. PFAS is the reason we all have Scotchgard, Teflon, and Gore-Tex in our closets and cupboards. Because of PFAS’s grease resistance, food packaging is a common use. Fast-food wrappers and microwave popcorn bags have a PFAS-based coating to prevent grease from soaking through the paper.
PFAS is also a major component in a product used to fight fires fueled by gasoline, aviation fuel, and other highly flammable materials. Aqueous Film Forming Foam, commonly called AFFF or A Triple F, is used to fight fires at airports, military bases, refineries, and chemical manufacturing facilities. While
AFFF is extremely effective in extinguishing fuel fires, its use has become a major source of PFAS in the environment. PFAS has been found in the drinking water of residents near several military bases and airports where AFFF use is required and has been used regularly in training exercises in addition to fire emergencies.
PFAS have become an issue in the environment because of their persistence, mobility, bioaccumulation, and low-level health effects.
Mobility: Many chemicals “stick” to the soil and do not move quickly in the environment. This is not so with PFAS. These chemicals dissolve and move readily in water, often creating large plumes of contaminated groundwater downstream of where they are introduced into the subsurface (e.g., military bases, airports, landfills, industrial facilities).
Bioaccumulation: When ingested, PFAS tend to build up in the proteins of people, plants, and animals. Because the human body does not break them down quickly, long-term exposure to PFAS can cause high levels to accumulate. In areas where PFAS has been found in rivers and lakes, health warnings have been issued for the consumption of many predatory fish due to PFAS concentrations in their meat. There have even been advisories posted in some deer hunting areas in Michigan.
Low-level health effects: Health effects, including increased risk of cancer, high cholesterol, and developmental issues, are suspected at parts-per-trillion (ppt) levels of PFAS. To put that into perspective, a part per trillion is equivalent to one second in 31,500 years. This is a thousand to a million times lower than a typical “safe” level of a contaminant.
How can PFAS affect dairies?
If a source of PFAS is near a dairy, the chemicals can travel in the groundwater to the dairy’s supply wells. A 4,000-cow dairy in Clovis, New Mexico, was depopulated and closed after PFAS from a nearby United States Air Force base contaminated seven of the dairy’s wells. In the dairy owner, Art Schaap’s, words, “This has poisoned everything I’ve worked for and everything I care about. I can’t sell the milk. I can’t sell beef. I can’t sell the cows. I can’t sell crops or my property.”
When Maine dairy farmer Fred Stone discovered his milk contained PFAS in 2016, he installed a water-treatment system and bought new cows. He thought that investment would get him past this issue. Recently, PFAS have shown up in the milk again. This case has wide-ranging implications due to the suspected source of the PFAS – sewage sludge (also called biosolids) that was spread on the nearby fields for decades. Subsequent testing found high levels of PFAS not only in the milk, but also in the soil, hay, and cow manure. As sewage sludge spreading is a historically widespread soil-amendment practice encouraged and conducted in all 50 states, this pathway for PFAS into the environment, particularly farms, is being investigated.
PFAS testing by FDA
How much concern should we have for the food produced in areas with PFAS contamination? The FDA is attempting to answer this question. Between 2012 and 2019, the Food and Drug Administration (FDA) tested a variety of food from areas known to be impacted by PFAS. PFAS was found in milk, meat, seafood, grain, and produce. Although PFAS was detected at low levels, the FDA concludes: “Based on the best available current science, the FDA has no indication that these substances at the levels found in the limited sampling present a human health concern.” Because there are no established “safe” levels of PFAS in food products, the FDA used a person’s average consumption, concentration in the food, and the limited toxicological studies to assess the potential risk of health effects.
How are PFAS regulated by the federal and state governments?
PFAS have only been regulated as a contaminant in the last few years and then mainly in drinking water. In 2016, the US EPA issued a Lifetime Health Advisory Level of 70 nanograms per liter (or parts per trillion [ppt]) of PFOA and PFOS (two specific chemicals in the PFAS family. It is important to note that this advisory level is not enforceable. The US EPA is currently considering whether to develop a Maximum Contaminant Level (MCL) under the Safe Drinking Water Act, which would set an enforceable standard for all drinking-water supplies.
Because there is no timeline for a federal PFAS standard, many states are taking matters into their own hands. As of August 2019, 20 states have promulgated some type of PFAS standard. Unfortunately, with each state taking its own view of the science and available data, a wide range of standards are in place depending on the location in question. For example, the state standards for PFOA range from 24,000 ppt in Oregon to 10 ppt in Vermont. This certainly does not mean that the risk from ingesting PFAS is any different in Oregon than Vermont, only that each state differs in how conservative they are considering the uncertainties in the data.
What can be done about PFAS?
Unfortunately, the very characteristics that make PFAS useful in our products also contribute to the difficulty in removing them from the environment. The only widely used method for destroying PFAS is incineration. Adsorption using activated carbon or special resin is often employed to remove PFAS from water, but that process simply concentrates the PFAS in a smaller volume.
Many landfills are accepting materials containing PFAS. Although landfilling does not remove the PFAS, it does isolate the PFAS in a space engineered to keep those chemicals from entering the environment. Until more cost-effective methods for PFAS destruction are developed, landfills just may be the best place for them.
PFAS are only going to be become more of a “hot-button” issue as more attention is brought to their ubiquitous nature. Many states are looking into the potential effects of sewage sludge (biosolids) application on farm fields, particularly with respect to dairy operations. To stay in front of this potential issue, farmers should keep an eye on research with respect to safe practices for sewage sludge application and standards for safe water use.
Listen for Matt Schroeder along with attorney Leah Ziemba on our DairyVoice podcast here or at DairyVoice.com.
Matt Schroeder is an environmental engineer with Dragun Corporation. Dragun has supported agriculture with environmental and permitting issues for over 30 years. For more information on PFAS, see Dragun’s PFAS Resources web page at https://www.dragun.com/pfas-resources/.
Jeffrey Bolin is vice-president of technical operations at Dragun Corporation, overseeing consulting, litigation support, engineering and environmental compliance, remedial investigation and operations of the company in the U.S. and Canada.