Blackgrass is sprayed with a pesticide© Tim Scrivener

A new regulatory system to assess the long-term effects of pesticides on the environment should be introduced, chief scientific adviser to Defra, Ian Boyd suggests.

In a paper in the journal Science, Prof Boyd draws many parallels between the use of antibiotics in human medicine and pesticides in agriculture.

“Both have been manufactured to [meet] market demand, with little care taken to consider whether this is sensible.

“Both are often used as therapies of first resort, when sparing use would be more appropriate.

“Both are vulnerable to loss of efficacy because of resistance in target organisms,” he said.

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But there is a clear and potentially dangerous distinction when it comes to regulation.

Pharmaceutical products and pesticides are rigorously tested for effectiveness, safety and any side effects before they are licenced, said Prof Boyd.

But following approval, only pharmaceuticals are then subject to on-going, long-term monitoring to ensure there are no untoward effects when used on a large scale.

“There is no equivalent post-marketing mechanism [for pesticides].

“The effects of dosing whole landscapes with chemicals have been largely ignored by the regulatory system.”

Prof Boyd noted the UK is no exception.

“The UK has one of the most developed regulatory and monitoring systems for pesticides, yet it has no systematic monitoring of pesticide residues in the environment.

“Without knowledge of safe environmental limits, the total pesticides used is governed by market demand rather than by a limit on what the environment can endure,” he explained.

Prof Boyd, therefore, called for a new system of post-approval vigilance to be established, with manufacturers and growers required to properly track the use and effects of pesticides in the environment.

“Such a system would promote genuinely risk-based pesticide use that would make the trade-offs between the environmental costs and food production more explicit.”

Mixed response from sector stakeholders

The Crop Protection Association (CPA) said the article made some “interesting points” but felt “the controlled environment of the pharmaceutical industry isn’t really comparable to the challenge of producing food sustainably within the context of a constantly changing environment”.

“Pesticides are among the most heavily regulated products in the world,” said CPA chief executive Sarah Mukherjee.

“This regulatory process, involving rigorous scrutiny by independent scientific experts, ensures plant protection products are safe before they reach the market.

“Once a product has been approved, manufacturers work tirelessly with farmers and agronomists to ensure our products are used appropriately and correctly.”

But anti-pesticides campaigner, Georgina Downs, described Prof Boyd’s comments regarding the failure of the current regulatory system to assess the real-life impact of pesticides as a “welcome surprise”.

“To see he has actually set down some of these failings, albeit still not strongly enough, is rather surprising, to say the least, considering the way successive governments and their advisers have refused to admit any failure in the policy and approach for pesticides in the UK,” she said.