Switzerland and Pesticides: Toxic relationship or necessary evil?

Swiss voters will soon decide if they want an outright ban on synthetic pesticides. Are the claims made by supporters and detractors of the ban true? And how do pesticides truly impact the population? A look at the facts.   

On June 13, Swiss citizens will vote on an initiative that seeks to ban the use of pesticides in the country. The backers of the initiative want to make illegal the use of synthetic weedkillers, insecticides, and fungicides in Switzerland’s agriculture sector as well as for private or commercial use. They also want to ban imports of such agents.  

The anti-pesticide committee, based in the French-speaking part of Switzerland, is made up of scientists, legal experts and farmers with no direct ties to any major political party. However, the initiative has received some political backing, most notably from the Green Party, which argues that the Alpine country has not done enough to combat pesticide use.   

“In an international comparison, Switzerland is at best in the middle of the pack when it comes to pesticide reduction,” the party argues on its website.  

Where does Switzerland rank internationally? 

Is Switzerland really an international laggard when it comes to the use of pesticides? Data on pesticide sales can give some indication of how well Switzerland is doing on limiting the use of pesticides. The Green Party uses figures compiled by the 37-country Organisation for Economic Co-operation and Development (OECD) to justify its claim. Those numbers do show that Switzerland is in the middle of pack when it comes to pesticide sales per unit of land.   

However, the figures only cover the period from 2011-2015. More recent figures (up to 2018) compiled by the United Nations’ Food and Agricultural Organization (FAO) show Switzerland’s pesticide use to be 4.9 kilogrammes/hectare. This puts the country in the same boat as France and the UK (as well as Turkmenistan, Georgia, Argentina and the Dominican Republic). Once again, it’s neither among the top nor bottom nations when it comes to pesticide use. 

But to judge a country’s approach towards pesticides it is also necessary to look at whether consumption has increased or decreased in recent years. A comparison published by Eurostat (the statistical office of the European Union) shows that sales of pesticide in Switzerland have diminished between 2011 and 2019 but not as much as other European countries over the same period. 

Quantity vs quality 

It is also worth paying closer attention to the patterns in the sale of different types of pesticides to better understand what is going on. Herbicide sales have decreased for six years in a row with sales of the controversial glyphosate shrinking by 63% over ten years. The top five best-selling pesticides in 2019 were sulfur (fungicide), paraffin oil (insecticide), glyphosate (herbicide), Folpet (fungicide in viticulture) and Mancozeb (fungicide). It is worth noting that sulfur and paraffin oil are permitted in organic farming and are also used in conventional agriculture. 

Switzerland may be “average with room for improvement” in a global context, but what does that mean for its population? The toxicity profiles of pesticides fall on a wide spectrum and the World Health Organization (WHO) has recently classified them on their potential to do harm to humans. When we cross-referenced the WHO hazard classification against a list of 360 active substances approved in Switzerland, we found 170 matches. The analysis revealed the presence of a pesticide that the WHO classifies as “extremely hazardous”: the active agent bromadiolone, sold in Switzerland under the trade name Arvicolon 200 CT. It is used in baits to kill a rodent called water vole that is considered a pest in horticulture and viticulture. Four substances fell into the “highly hazardous” category (abamectin, methomyl, tefluthrin, zeta-cypermethrin) while about a hundred others were classified as “moderately hazardous” and “slightly hazardous”. 

Switzerland is managing to reduce the use of some types of pesticides in domestic agriculture, but it has not addressed imports, which is important to consider because most of Swiss residents’ plant-based calories (60%) come from abroad.  

According to an investigationExternal link by the advocacy group Public Eye, “more than 10% of imported foods tested by the authorities in 2017 contained residues of pesticides banned in Switzerland because of their harmful effects on health or the environment”. Data from the Federal Food Safety and Veterinary Office also showed that 52 banned pesticides were found in that year’s testing. Thus the danger to consumer health is likely to be underestimated if imports are not taken into account.   

Verdict: Mostly true  

Based on international comparative data, Switzerland is in the middle of the pack when it comes to pesticide sales and limiting their use. However, it has made more progress in reducing some type of pesticides (like herbicides) than it is given credit for. The kind of pesticides approved for use in the country are generally not the most toxic and over 40% of plant protection products sold can be used in organic farming.  

Hidden dangers  

A risk factor that is seldom accounted for is the persistence of some pesticides in bodies of water, groundwater and soil. Bernhard Wehrli, a Swiss professor of aquatic chemistry, mentions the herbicide atrazine that has long been banned in Switzerland but can still be detected decades later. He also warns against the metabolites of pesticides that in some cases are more soluble in water and have a longer life than the pesticides themselves. One such agent is the fungicide chlorothalonil that is still in use in Switzerland but for which the authorisation has not been renewed in the EU due to potentially carcinogenic effects. A recent scientific analysis of 31 groundwater samples found metabolites of chlorothalonil in all of them and new metabolites in 20 of the samples. According to the researchers, the properties of these metabolites make them difficult to filter or degrade even with more advanced water treatment technologies such as activated carbon and ozonation.   

Finally, there is a seldom-discussed factor influencing the amount of pesticides used in any given year: the weather. While technologies like weed-control robots have reduced the quantity of weedicides, the application of other synthetic pesticides like fungicides changes depending on weather conditions. Eva Reinhard, the head of Swiss research body Agroscope says this is because in warm and wet years fungi and bacteria multiply exponentially resulting in higher use of fungicides. Using potato blight as an example, Reinhard says work is underway to develop resistant varieties – but it depends on the public’s acceptance of genetically modified foods.    

“[Genetically modified potatoes] are resistant to the blight pathogen and don't need to be sprayed,” she says. “We’re faced with conflicting objectives: consumers do want pesticide-free products, but they’re not yet prepared to accept genetically modified plants.” 

Source: https://www.swissinfo.ch/eng/switzerland-and-pesticides--toxic-relationship-or-necessary-evil-/46606208