Risks of systemic pesticides confirmed
The conclusions of a new meta-analysis of the systemic pesticides neonicotinoids and fipronil (neonics) – the most widely used pesticides in the world – confirm that they are causing significant damage to a wide range of beneficial invertebrate species and are a key factor in the decline of bees.
Concern about the impact of systemic pesticides on a variety of beneficial species has been growing for the last 20 years, but the science has not been considered conclusive until now.
Undertaking a full analysis of all the available literature (800 peer reviewed reports) the Task Force on Systemic Pesticides – a group of 29 global, independent scientists from four continents, who are also advisers to the International Union for Conservation of Nature (IUCN) – has found that there is clear evidence of harm sufficient to trigger regulatory action.
Unlike other pesticides, which remain on the surface of the treated foliage, systemic pesticides are taken up by the plant and transported to all the tissues (leaves, flowers, roots and stems, as well as pollen and nectar).
The metabolites of neonics and fipronil (the compounds that they break down into) are often as, or more, toxic than the active ingredients to non-target organisms. Both parent compound and some of their metabolites are able to persist and environmental concentrations can build up, particularly in soil, over months or years. This increases their toxicity effects and makes them more damaging to non-target species.
Facility managers responsible for golf courses, lawns, and garden areas should check product labels carefully. Words to look out for are: fipronil, imidacloprid, clothianidin, acetamiprid, thiacloprid and thiamethoxam.
Neonicotinoids are widely used in Australia and, while the Australian Pesticides and Veterinary Medicines Authority has recently conducted a review, as yet there are no restrictions on their use. However, since 2013 beekeepers has been demanding retailers stop stocking products containing the compounds. Product names include: Confidor, Termidor, Kohinor, Admire, Advantage, Gaucho, Merit, Hachikusan, Premise, Prothor, Winner, Gaucho, Titan, Clutch, Belay, Arena, Assail, Intruder, Adjust, Calypso, Actara, Cruiser, Helix, Platinum, Centric, Regent, Frontline TopSpot, Fiproguard, Flevox, Chipco Choice and PetArmor.
“If you use them every year they accumulate, they get into the soil water and hence into streams. So essentially we are contaminating the global environment with highly toxic, highly persistent chemicals,” says David Goulson, professor of biology at Sussex University and one of the report’s authors.
“The focus to date has been on honeybees, but it’s clear that the impacts of neonics are more profound than that. The story goes far beyond bees. It goes to all wildlife.”
Although the study was a review of existing papers, representatives of the pesticide industry have responded with the claim that it revealed nothing new.
“There is very little credible evidence that these things are causing untoward damage because we would have seen them over 20 years of use,” says Dr Julian Little from Bayer, one of the manufacturers of neonicotinoids.
The European Crop Protection Association which represents pesticide manufacturers accused the task force of being selective in their evidence, pointing to recent studies carried out by pesticide industry itself suggesting that the declines in bee populations have been overstated.
However, no one is arguing that declines in bee populations have occurred. Further, Europe has instated a two-year moratorium on the use of neonicotinoids on flowering crops. The US Government has announced the creation of a pollinator health task force to examine the impact of pesticide exposure on bees and other insects.