Dutch report warns that rapid growth of PFAS pesticides in agriculture is a threat to drinking water

The use of PFAS pesticides in agriculture and horticulture in the Netherlands has increased by about 67 percent over the past three years. This is shown in a new report from the Dutch research and advisory agency CLM on the use of PFAS-containing pesticides and the risks for groundwater, soil and drinking water.

There are many concerns about the impact of PFAS on humans and the environment, but little is known about the details. The association of Dutch drinking water companies Vewin and seven Dutch provinces asked CLM to investigate which PFAS pesticides are authorised in the Netherlands and how often they are used. At the moment, 25 active substances are authorised that are PFAS compounds: 10 fungicides, 8 herbicides, 7 insecticides and 3 adjuvants. In total, 115 products on the market contain one or more of these PFAS pesticides, according to the CLM report.

Strong growth of PFAS-containing fungicides

PFAS stands for per and polyfluoroalkyl substances. These substances do not occur in nature but are man made and hardly break down. They are used in fire extinguishing foam, non stick pans and clothing. PFAS is also used in pesticides because it makes the product stick better to the crop. Since the early 1990s, PFAS pesticides have been authorised in Dutch agriculture and horticulture. While the total sales of crop protection products are decreasing, the use of PFAS containing products is rising sharply. It increased from about 150,000 kilos in the period 2010 to 2020 to more than 250,000 kilos in 2023. The highest sales involve fungicides and this is also the category with the strongest growth. The top three provinces where the most PFAS pesticides are used are Noord Holland, Groningen and Drenthe. According to the report this is due to the large scale cultivation of potatoes, sugar beets, silage maize, winter wheat, lilies and tulips in these provinces. PFAS containing crop protection products are widely used in these crops.

Trifluoroacetic acid is difficult to remove

Although the CLM researchers had to work with limited available data and literature, the findings confirm the concerns that unwanted spread of PFAS pesticides to groundwater and soil is taking place. In the soil they break down and metabolites are formed. From the 25 authorised PFAS pesticides, at least 134 metabolites can be formed and 75 percent of these metabolites are also PFAS compounds. The best known of these is trifluoroacetic acid (TFA), a PFAS with a short molecular chain that is very difficult to remove through water treatment. This TFA is found in elevated concentrations in the groundwater at many monitoring points in all provinces.

Extra monitoring is needed

The researchers urge the provinces and Vewin to raise the issue with the ministries and with the Dutch Board for the Authorisation of Plant Protection Products and Biocides (Ctgb). According to them, the provinces and the national government can do more to protect groundwater as a source for drinking water. They make several concrete recommendations for the authorisation policy, monitoring and registration of products. One recommendation is to communicate actively with the agriculture and horticulture sector and inform users about the PFAS pesticides that are on the market. For this purpose, they have created an overview containing all 25 substances and 115 products.

Vewin calls for European PFAS restrictions

The use of PFAS containing crop protection products results in large, irreversible leaching of the breakdown product into groundwater and therefore into drinking water sources, Vewin states in response to the CLM report. Vewin calls for the fastest and broadest possible implementation of the European restriction proposal for PFAS. In anticipation of this, emissions in the Netherlands must be reduced quickly. Just like Denmark, the Netherlands should introduce a ban on PFAS containing crop protection products.

This article was published first by the Dutch platform for water professionals H2O Magazine