Study suggesting neonicotinoids are safe is severely flawed says scientists

Wednesday 11th November 2015

A paper published last week in Environmental Sciences Europe has criticised a study funded by pesticide manufactures. The study by agrochemical giant, Syngenta claims to show that one of the insecticides which they produce is safe for honeybees, however an analysis by an independent group of scientists shows that these claims are unfounded.

 The study was published in scientific journal PLOS ONE and was based on the use of thiamethoxam when used as a treatment for maize and oilseed rape seeds. Thiamethoxam is one of three chemicals known as neonicotinoids which have been identified as being harmful to wildlife including honeybees and bumblebees and have now been restricted by the European Commission.

A group of scientists from across the world have analysed the study and concluded that there are serious flaws and also controversy in how the study was published. However, Syngenta had concluded that the residues of the chemical in the pollen and nectar of the crops were a “low risk” for honeybee colonies.

The paper identified a number of issues with the study

  • The insecticide used was not one which would be used on crops. The ones which are used in the fields are commercial products and have more chemicals added to them which can make them more potent.
  • The coating of thiamethoxam on the seeds were claimed to be at “the maximum approved label rate”, when actually only 30-80% of the maximum allowed dosage was actually used.
  • The hives were only placed 2km apart which is not far enough away from each other as honeybees can travel further to find food
  • The bees were only exposed for a very short space of time, between 5 to 23 days and were then kept in a ‘pristine’ environment which doesn’t happen to bees under normal circumstances, and even then 70% of the colonies died throughout the whole experiment.
  • There is not a single statistical analysis in the study – It is standard scientific practice that proper statistical analyses support the claims made, and to work out whether or not two sets of data differ from each other.
  • A freedom of information request had discovered an email exchange between Syngenta and a UK employee in the Government department of pesticide regulation. The employee had been asked by PLOS ONE to anonymously review the study however the emails showed that Syngenta was in contact with the employee over the review process.  After the paper had been reviewed, the employee then went to work for Syngenta and later appeared as an author of the paper at an international conference.

One of the authors and Pesticides Officer for Buglife, Vanessa Amaral-Rogers said “Given all these issues, it was surprising that the study had been published. It’s also concerning that there are these close ties between the pesticide regulators and the agrochemical companies. The regulators are supposed to be independent but it appears that this has certainly not been the case in this instance.”

Dave Goulson, Professor at the University of Sussex and another of the authors said “The European Commission is currently reviewing the neonicotinoid restriction and will be taking into account any new data. As publications in refereed journals are likely to be taken seriously in political debates and policy-making, they must be based on valid experimental designs and analyses, otherwise they are potentially misleading.”