PFAS Chemicals Spread Through Contaminated Pesticides

In a previous article, ‘Latest Insights Relating to PFAS in Food Packaging Materials,’ we described the nature of per- and polyfluoroalkyl substances (PFAS) and considered their impact on human health and the environment. In particular, we focused on the European Food Safety Authority’s risk assessment and monitoring in the European Union. In this article, we look at recent events in the United States and the discovery that pesticides used to control mosquitoes have been contaminated with PFAS derived from fluorinated packaging. The potential spread of these chemicals across millions of acres of the US, triggers EPA action. The introduction of regulatory support on this topic is in awaiting.

Preliminary tests commissioned by PEER (Dec 2020) 

In December 2020, Public Employees for Environmental Responsibility (PEER) published results that showed high levels of PFAS compounds in a pesticide widely used to control mosquitoes – Anvil 10+10. This raised the alarm of the potential widespread of these ‘forever chemicals’ throughout the land of 23 States.

This insecticide has been used extensively, sprayed aerially and from vehicles, across a variety of different US states, including Massachusetts, Florida and New York.  PEER’s analysis of the product found that a content level of roughly 250 ppt (part per trillion) for PFOA that had mostly been phased out, and 260-500 ppt of HFPO-DA, also known as ‘GenX’. PEER concluded that, although PFAS chemicals can be included in pesticide formulations as a surfactant, anti-foaming agent or dispersant, there was no clear evidence as to whether the identified PFAS were intentionally added or had leaked from packaging.

PEER also noted that PFAS are listed as approved inert ingredients by the Environmental Protection Agency (EPA) and that patents showed PFAS were being used by chemical companies. This has led to additional concerns and the proposal that other products, including other pesticides, might also be involved in further investigation.[1]

MADEP tests confirm PFAS presence in the pesticides

The Massachusetts Department of Environmental Protection (MADEP) has addressed PEER’s notification, following them up with independent tests that found eight different PFAS, including PFOA and PFOS.

EPA confirms contamination from fluorinated packaging and takes action (Mid Jan 2021)

In a press statement published on January 14, 2021, the EPA confirmed the presence of PFAS as a consequence of them leaching from fluorinated HDPE containers, which are used for chemical storage and transportation.[2] In the fluorination process, high-density polyethylene containers are covered with a chemical barrier that should improve stability and protect the product from chemical changes.[3]

The EPA has issued a subpoena under the Toxics Substance Control Act (TSCA) on the company that fluorinates the containers, requesting information about the application process, while the affected pesticide manufacturer has voluntarily stopped shipping products stored in fluorinated containers.[4]

In addition, the EPA has initiated an investigation into the possible impact of this contamination on the environment and human health. Furthermore, they have asked fluorinated container providers and companies using fluorinated containers, to identify potential sources of contamination. In their statement, the EPA acknowledges the urgent need for guidance covering the purchasing and use of mosquito pesticides, and will provide more information as soon as they become available.

Potential classifications of per- and polyfluoroalkyl substances; Image Source: The high persistence of PFAS is sufficient for their management as a chemical class

Public Concerns About Chemical Safety

Several public safety watchdogs and environmental organizations have expressed concern about these findings. They have called on the authorities to act, asking them to set strong, enforceable standards and clear regulations. In addition, they have requested a ban on PFAS and for them to be designated as hazardous substances.[5] 

Moreover, a publication from  December 2019 reports data on the high presence of per- and polyfluoroalkyl substances in the rainwater in some parts of the US; when detected in the drinking water, these levels can trigger regulatory action.[6] In the laboratory tests from January 2020 commissioned by The Environmental Working Group (EWG), the presence of the PFAS chemicals in the drinking water was confirmed in different US cities and metropolitan areas, underlining that the exposure to these chemicals has been underestimated by the previous studies on potable water.[7]

New findings on the Health impact - PFAS influence on the severity of COVID-19 and potential interference with vaccine

These so-called ‘forever chemicals’ have earned their name based on their bioaccumulation in living creatures and their extreme persistence in the environment. They are linked to a range of serious health conditions, with the most critical effects being on the immune system.[8]

This is of particular concern during the current pandemic, where recent studies have found that elevated exposure to perfluorinated alkylates can aggravate the severity of COVID-19 infections.[9] A paper published in October 2020, focusing on monitoring five PFASs known to be immunotoxic, found a positive correlation between the accumulation of these substances in the lungs, particularly PFBA, and an increase in the risk of a severe course of SARS-CoV-2 infection.[10] 

Furthermore, a review of PFAS immunotoxicity properties has found strong evidence to suggest a suppression of the antibody production after vaccination in animals and humans with high blood levels of PFAS. Different research studies have shown a weaker response to vaccinations of various types, such as tetanus, tetanus-diphtheria, and flu vaccine, as well as that PFAS immunotoxicity can affect vaccine response later in life.[11]

Conclusions

Concerns over the impact of PFAS use are continuing to grow amongst authorities and public health and environmental protection organizations. Despite a high level of diversity in PFAS, they all contain perfluoroalkyl moieties that are extremely resistant to environmental and metabolic degradation. The vast majority of PFAS are therefore either non-degradable or will ultimately transform into stable terminal transformation products, which are still PFAS. It is this high persistence that makes them a particular concern for scientists, who recommend the phasing out of all non-essential PFAS use.[12] 

Stakeholders should therefore expect the introduction of regulatory support to implement the phasing out of PFAS use and greater scrutiny into usage and the ultimate elimination of contamination sources of these man-made ‘forever chemicals’.

Follow-up reading:

An overview of the uses of per- and polyfluoroalkyl substances (PFAS), DOI: 10.1039/D0EM00291G Environ. Sci.: Processes Impacts, 2020, 22, 2345-2373

“In total, more than 200 use categories and subcategories are identified for more than 1400 individual PFAS. In addition to well-known categories such as textile impregnation, fire-fighting foam, and electroplating, the identified use categories also include many categories not described in the scientific literature, including PFAS in ammunition, climbing ropes, guitar strings, artificial turf, and soil remediation. We further discuss several use categories that may be prioritized for finding PFAS-free alternatives. Besides the detailed description of use categories, the present study also provides a list of the identified PFAS per use category, including their exact masses for future analytical studies aiming to identify additional PFAS.”

The high persistence of PFAS is sufficient for their management as a chemical class, Environ. Sci.: Processes Impacts, 2020,22, 2307-2312

"The continual release of highly persistent PFAS will result in increasing concentrations and increasing probabilities of the occurrence of known and unknown effects. Once adverse effects are identified, the exposure and associated effects will not be easily reversible. Reversing PFAS contamination will be technically challenging, energy intensive, and costly for society, as is evident in the efforts to remove PFAS from contaminated land and drinking water sources."

Current Contributions of Organofluorine Compounds to the Agrochemical Industry, ScienceDirect, Volume 23, Issue 9, September 2020, 101467 

“Our database covers 424 fluoro-agrochemicals and is subdivided into several categories including chemotypes, mode of action, heterocycles, and chirality. This in-depth analysis reveals the unique relationship between fluorine and agrochemicals.”

References:

[5]https://www.foodandwaterwatch.org/news/pfas-discovered-common-pesticide-sprayed-millions-acres#:~:text=PEER%20found%20that%20Anvil%2010,and%20polyfluoroalkyl%20substances%20(PFAS) & https://www.ecowatch.com/pfas-aerial-pesticides-2649108690.html?rebelltitem=2#rebelltitem2 & https://beyondpesticides.org/dailynewsblog/2021/01/epa-confirms-widespread-pfas-contamination-of-pesticides-announces-investigation-stops-short-of-action-to-protect-public/ &
https://www.foodandwaterwatch.org/news/pfas-discovered-common-pesticide-sprayed-millions-acres#:~:text=PEER%20found%20that%20Anvil%2010,and%20polyfluoroalkyl%20substances%20(PFAS)