The European Food Safety Authority last week published the results of a scientific review of the risks posed by pesticides to bees in the European Union. The food safety watchdog said there is a need for improvements in the EU’s risk assessments for the effects of pesticides on bees.

The EFSA announcement follows calls from conservation organisations including Friends of the Earth to suspend use of neonicotinoid pesticides, after a number of studies released this year have linked the pesticides with adverse effects on bees. The organisation has called on UK Prime Minister David Cameron to introduce a National Bee Plan to support the insects, whose numbers and varieties have been hit hard in recent years.

Whilst agchem companies blame the decline on disease and loss of habitat, scientific evidence is increasingly implicating certain pesticides in the bee deaths. Between 1985 and 2005, two British bumblebee species became extinct, solitary bees declined in over half the areas where they were studied and honey bees in managed colonies saw a 53 per cent decline in the UK alone. 

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It is estimated that about 80 per cent of the 264 crop species cultivated in the European Union depend directly on insect pollinators, with honey bees playing the most significant role; this ‘ecosystem service’ carried out for free by bees and other insects is estimated to be worth billions of Euros annually to farmers in the EU.

Increasingly, policy makers are becoming aware of the intrinsic value of nature and have begun to factor environmental considerations into their policy decisions, although to do this they have initially had to ascribe monetary values to ‘ecosystem services,’ a process which gained widespread recognition following the UK government’s National Ecosystem Assessment.

Review examines current testing model

The EFSA study covered impacts on honey bees, bumble bees and solitary bees. It said the work will be used to create guidance on risk assessments for crop protection products for use by industry and public bodies. The review was conducted in response to a request by the European Commission, which ordered the study following increasing pressure from MEPs, beekeepers and conservation groups.

EFSA’s Panel on Plant Protection Products and their Residues (PPR) looked in detail at four key areas, as suggested by the European Commission:

• the acute and chronic effects of pesticides on bees, particularly colony survival and development
• how to estimate the long-term effects of exposure to low concentrations
• the need to take into account the cumulative and combined effects of different pesticides
• existing test protocols and possible new protocols that take account of the exposure of bees to pesticides through nectar and pollen.

EFSA recommends stricter testing

The researchers proposed splitting assessments into two separate schemes: one for honey bees, and one for bumble bees and solitary bees. Having examined current assessment methods, the experts made recommendations based on shortcomings in the areas of sub-lethal doses, long-term effects and exposure routes.

Under their recommendations, testing of chemicals would include exposure to adult bees and larvae over periods of seven to ten days, which is currently not required by standard tests.

EFSA pesticides experts also recommend improvements to existing laboratory, semi-field (cages, tunnels and tents) and field testing procedures, arguing that current testing did not adequately cover all possible means of exposure to chemicals. The scientists found faults with current testing methods in that “Several exposure routes (intermittent and prolonged exposure of adult bees, exposure through inhalation and the exposure of larvae) are not currently evaluated in laboratory tests, and the effects of ‘sub-lethal’ doses of pesticides are not covered fully.”

They said that several “weaknesses” in current testing methods have led to oversights and uncertainties in measuring the actual effect on bees, including detecting bee mortality and measuring the “sub-lethal” and long-term effects of chemicals on the pollinating insects.

An EFSA spokesperson said the Authority’s scientists are currently developing further guidance on the effects of pesticides and genetically modified organisms (GMOs) on bees and are expected to identify areas for further research. The spokesperson stated, “EFSA’s pesticide experts are also preparing a statement on two articles published recently in the journal Science which suggest links between neonicotinoids and bee colony survival.”

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