German-Dutch research to be presented on Friday has shown the presence of a ‘cocktail’ of chemicals in eight protected areas of countryside in Drenthe and 14 in Gelderland.

The mix of dozens of different pesticides and weed killers, including traces of the banned pesticide DDT, is linked to a disastrous decline in insect populations. The researchers reported similar findings for Germany.

‘One substance may be more prevalent than another but the situation in all areas is the same. They are heading to a point of no return,’ agricultural researcher Jelmer Buijs, who headed both the German and Dutch projects, told Trouw.

One of the pesticides found is the powerful chemical permethrin, which has been banned for use in agricultural in Europe since 2000.

Earlier German-Dutch research had already shown that insect populations in Europe have fallen by 75% since 1990, with disastrous consequences for birds and insect eaters, and biodiversity as a whole.

Some two years ago Buijs’ fellow researcher Margriet Mantingh found no fewer than 134 pesticides in the soil, manure and animal feed on farms in Gelderland using the dung beetle as an indicator. The more pesticides, the fewer dung beetles were found.

The current research results looked at the presence of 664 harmful chemicals. Of those, 34 were found in the Gelderland countryside. Most were pesticides but weed and fungus killers were also present in the mix. Half of the chemicals can cause cancer and 42% can cause hormonal abnormalities.

The use of pesticides is not allowed in protected areas but make their way in via water and wind, sometimes travelling great distances, the researchers said.

‘One of the pesticides, cyenopyrafen, was banned in Europe but is still used in China and Japan. It was either imported illegally or blown here by the wind. But most chemicals were found to come from Europe. If we are taking the loss of the insect populations and biodiversity seriously we have to tackle pesticide use here,’ Buijs said.