Pesticide safety research shouldn’t be left to the chemical companies that make them

After the pesticides we spray, who will be left flying? John Severns

The UK government is prepared to accept funding for studies on the risks of pesticides to bees and other pollinators from the manufacturers of the chemicals in question. Not surprisingly, this raises uncomfortable questions about trust and transparency, as a report from the Environmental Audit Committee points out.

I share their concerns that the Department for the Environment, Food and Rural Affairs (Defra) has insufficient capacity to monitor environmental safety and to carry out the sort of urgent testing needed for these neonicotinoid pesticides. The testing demanded is limited to industry-funded field trials.

Will the fields chosen for outdoor trials reflect all fields where neonicotinoids may be used? Unlikely as most environments are complex and unique. Therefore, conclusions are hard to interpret – there are so many influencing factors including weather, disease, habitat structure and the use of other pesticides. And despite all farmers being required by EU regulations to record their use of pesticides, this information is not collected in the UK. Without knowledge on how farmers have used pesticides, singly and combined together, a huge unknown risk exists – not just to insects, but all life.

Field studies cannot replace the lab

Lab studies simplify a problem by breaking it down into testable hypotheses, in carefully controlled experiments, with other potential varying factors removed. Field studies can control some factors, but this is at the expense of being realistic – their claimed advantage. Alternatively, as Defra proposes, one can include other variables into the analysis. An excellent idea, but the experiments would need to be impossibly large, and one critical variable is missing – the presence of other pesticides – as Defra does not currently consider this important. The fact is we need both laboratory and field trials, and a more rigorous understanding of what insect pollinators are important and affected, the impact of different habitats and threats, what pesticides are there and how these all interact.

Without adequate funding, we cannot hope to acquire this full scientific knowledge, and so we should adopt a precautionary principle wherever evidence of risk exists. This shouldn’t consider economic interests. It should be use-dependent, and consider what alternatives exist. Regardless of your opinion on the risks of neonicotinoid pesticides, nobody would recommend replacing them with even more toxic compounds; yet alternative pesticide options are not compared side by side in order to make a strategic choice.

Which questions, and who to ask them?

It has become clear that a simple lethal dose at which 50% (LD50) of bees or pollinators die is too crude a test to gauge a pesticide’s environmental risk. Which insects should be studied? In the laboratory, choices are limited due to issues of which insects can be easily bred and adapted for tests. In the field, we need a baseline to know what existed beforehand. What test? We need more assessment carried out on individual insects and how this impacts a colony’s performance. We also need to know about how long and in what concentrations pesticides persist in the environment.

Finally, we must investigate the effects of chemical cocktails. We can only achieve this through laboratory studies, and a mechanistic approach to screening. If we accept Defra’s view that only field studies are required, then we can never understand the full risk potential of chemical cocktails. But by combining the careful monitoring of insect pollinator populations (both managed and wild) and the information farmers record of which pesticides they use and how, we could actually learn from past mistakes using real field data.

Who pays?

If the results are to be trusted by the public, the industry cannot be given control. Yet it is the pesticide chemical industry that needs the data in order to get approval for their products, for which they stand to financially benefit. So it’s obvious the industry should pay – but they must not control the research. Funds for such research should be collected by Defra and passed to research council funding agencies such as BBSRC and NERC to distribute anonymously to expert independent academic laboratories for blind testing. The researchers should know only what is essential to conduct safety tests in the field and laboratory. Industry should also be blinded to the identity of the researchers throughout, but receive the full dataset for comment.

This conflict of interest between safety and profit isn’t impossible to break. There is an urgent need for evidence of neonicotinoids’ safety, and perhaps anonymity can’t be achieved this time. Nevertheless the industry must not be involved at any stage of the research until after the findings have been peer-reviewed and published. Because if the public can’t trust the results, then the money has been wasted.