According to this report from UK charity the Pesticide Action Network and the Soil Association, mixtures of pesticides can be more harmful to human health than the sum of the toxicity of the individual pesticides would suggest.
These mixtures, known as pesticides cocktails, are widespread in both food and the environment in the UK. For example, over a third of fruit and vegetables in the UK contain traces of more than one pesticide, while multiple pesticides were also found in 43% of bumblebees and 67% of soil samples. 25% of UK soil samples had traces of more than six different pesticides at once.
The report calls for the UK government to use the UK’s planned departure from the European Union as an opportunity to support farmers to significantly reduce pesticide use and shift to alternatives such as integrated pest management.
Read the full report, The Cocktail Effect: How pesticide mixtures may be harming human health and the environment, here. See also the Foodsource resource How are food systems and health connected and influenced?