The first question to ask the industry is whether the glyphosate might be from a hive feed supplement that has become increasingly popular in recent years rather than assuming it is pasture sourced.
Beekeepers use the product along with raw sugar to boost hive feed supplies in cold periods.
MPI checked 270 raw honey samples and 90 retail packaged products of mono and multi-floral honey. It found 77.7% had no glyphosate residue.
Only 1.7% of the raw, unblended honey had levels that would have exceeded regulations had they been offered for sale and none of the retail samples contained glyphosate levels over regulatory limits.
Just under 20% of the other samples were found to have residue between the lower lab detection limit and regulatory level limits.
“We need to know if there may be any residues in this hive product. It is a plant-based product and something that has never been tested for glyphosate.”
He estimates about half of beekeepers use the supplement.
But regardless of the source, advances in residue detection equipment mean residues can be detected at lower and lower levels far from being toxic to humans.
The regulated domestic maximum residue limit for glyphosate 0.1mg/kg or 100 parts per billion and many labs can detect down to 10 parts per billion.
MPI’s website says a five-year-old eating honey up to the regulated 0.1mg/kg level would have to eat 230kg of it every day for the rest of their life to be affected.
Most of the samples with glyphosate detected were clover and pasture, multi-floral varieties.
Of those detected above the lab lower limits of 0.01mg, two thirds were clover-pasture blend and a third non-clover pasture blend. There was no distinct link between residue and geographic locations.
Goodwin said NZ is overstocked with bees, with more than a million hives, up from 250,000 10 years ago.
That could push bees to travel more extensively to gather pollen and nectar, sometimes from areas beekeepers might not have envisaged when setting up hives, where glyphosate might be present.
NZ Beekeeping president Jane Lorimer said keeping glyphosate out of honey is a priority but hard to do.
“As beekeepers we can’t guarantee it will not end up in honey. It is a concern but in context of how much you have to eat to be harmful that is a lot. But we don’t like pesticides and herbicides because of the effect they can have on bees.”
Goodwin’s work has shown the surfacants used when applying glyphosate, rather than the poison itself, can have the most damaging effect on bee health.
Lorimer said it is so hard to guarantee no contact with residues the industry has avoided making any claims of being 100% free of them.
“It is simply too risky.”
She questions whether tests done on other foodstuffs might also reveal a low level of glyphosate residue.
Apiculture NZ chief executive Karin Kos said the greatest threat posed by such residues is not to human health but to consumer perception of honey and honey products.
She agrees with Goodwin, more has to be understood about glyphosate residues and the industry intends to work closely with MPI to do so.
“And we have to remember 98.3% of all the samples were well within regulatory limits.”
The 1.7% that was not was raw, extracted honey that had yet to be blended before sale.
“Beekeepers do what they can, including regular sampling and we need to be led by science but are aware consumer perceptions. We intend to keep educating beekeepers and talking to landowners about spray use.”
