As European Union (EU) risk assessments purportedly “confirm” that systemic pesticides threaten honeybees and lawmakers quickly clamor for pesticide bans, the stark reality is that so far in this process, political concerns have been trumping science. In fact, politics has prevented scientists from considering the bigger picture, and, as a result, both bees and the world’s food supply will suffer.
At issue is a class of pesticides known as neonicotinoids (also referred to as neonics) and whether they pose an unreasonable risk to bee species, including both commercially farmed honeybees as well as wild bees. Neonics are “systemic,”—plants absorb the pesticide and kill insects that eat the plants. This systemic approach actually limits the need for farmers to spray pesticides into the environment, reducing the impact to non-target insects, such as bees that take nectar and pollen but do not eat plant leaves. Neonics can be sprayed on plants, applied to the ground, or applied to the seeds of the plants.
During the past couple decades, many beekeeper have seen entire colonies of honeybees disappear or die off, and many thought these pesticides were to blame. But much research has indicated, the most significant risks to colonies come from diseases, habitat challenges, and even poor domesticated honeybee husbandry. Even then, honeybees are not threatened with extinction as the number of managed honeybee hives has grown worldwide. At most, pesticides might provide additional stress to the bees but are unlikely a major cause of colony loss. Given the fact that neonics have a lower impact than other pesticides, such risks are manageable, particularly given the benefits in helping farmers produce food.
The recent “risk assessments” issued by the European Food Safety Authority (EFSA), however, apply an excessively precautionary approach that makes little sense. EFSA assessments addressed three neonic products: clothianidin, imidacloprid, and thiamethoxam. Supposedly, these assessments offer “new” findings that have “confirmed” that these chemicals are high “risk to bees.”
The publicly available versions of these assessments are very technical, and it may be impossible to determine exactly how the authors arrived at their conclusions with the information provided. But you don’t have to look that hard to find the conclusions highly questionable.
First, it’s important to recognize that the EFSA assessments do not really represent “new” research. They are mostly a review of other studies—some of which EFSA has reviewed in prior assessments, as well as more recent studies. It’s worth noting further that the research on this topic is all over the map, with some compelling studies combined with a large number of studies that rely on questionable methodologies and raise more questions than provide answers. It’s difficult to determine from the published assessments whether EFSA is placing too much weight on lower quality studies.
EFSA developed various theoretical scenarios to study the possible impacts of neonics on bees, which it presents in a serious of tables. For each scenario, it considers research on the topic (although it’s unclear which studies they use for each scenario) and then describes what it believes the research shows. If the research shows any impact, it then draws a conclusion as to whether the chemicals should be considered “high” or “low” risk. For example, one table addresses the possible impact for honeybees that forage in a corn field, where they are exposed to a “high dose” of neonics. EFSA assess what the research shows for various factors, such as colony health, mortality of the hive, how exposures might impact the bees’ abilities to navigate back to the hive, and other things.
For nearly all scenarios, EFSA describes existing research as either “inconclusive,” or as demonstrating nothing more than “weak evidence for greater than negligible effect,” or “moderate evidence of negligible effect.” Out of dozens of scenarios described, only a handful (I counted two: one for imidacloprid and one for thiamethoxam) were described as having “strong evidence for larger than negligible effect.” These both were for bumble bees for which there is little data, and exposures appear to have been based on estimates rather than actual data.
Ultimately, it appears that EFSA bases its overall conclusion on a handful of outliers. An EFSA Q&A paper on the topic explains it this way:
EFSA compared the expected levels of neonicotinoid pesticides to which bees are likely to be exposed in the environment to those that cause effects to bees. Whenever the estimation of the environmental contamination was higher than the levels considered safe for bees, a high risk was concluded. For all the outdoor uses of these substances, there was at least one aspect of the assessment indicating a high risk, leading to the conclusion that overall these neonicotinoids represent a risk to bees.
They might as well have said it more plainly: Because we can’t prove that the pesticides pose negligible risks in every possible scenario, we assume they pose high risks in nearly all.
That does not sound very conclusive, and one would expect a call for more research rather than a confirmation of anything. And even if there is strong evidence of some effects that are “more than negligible” in a handful of scenarios, does it matter? How significant might such effects prove? Do we have any information to indicate that in those few scenarios, the effects could actually have any impact on species populations?
It’s clear that EFSA does not ask the right questions. The real issue is whether risks are significant in terms of species survival and whether the risks outweigh important benefits associated with using these products. Benefits include not only reduction of crop damage that makes food more affordable, but whether these products pose more or less risk than do alternatives. There is no getting around the fact that there will be alternatives because crop damage from pests must be controlled if we can expect farmers to feed the rest of us.
On that basis, neonicotinoids are excellent products that have a lower environmental impact that alternatives, because they don’t require regular spraying of fields that can hit non-target insects. And farmers find them helpful in increasing production, otherwise they would not pay for them.
Despite the flimsy quality of the EFSA evidence, lawmakers in Europe are poised to make a 2013-imposed temporary ban permanent, which has already done more harm than good. Lawmakers’ response is not surprising given that nearly every news headline on the topic rubber stamps the EFSA’s foolish conclusions.