Dr Edward Mitchell, a soil biologist at the University of Neuchâtel in Switzerland and study co-author said "On the global scale, the contamination is really striking".
In one third of the honey, the amount of the chemical found was enough to be detrimental to bees. An updated assessment that is slated to appear in the journal Environmental Science and Pollution Research found even stronger evidence that the insecticides are harmful, and reportedly concludes: "The consequences are far reaching and can not be ignored any longer".
Harvesting honey around the world, researchers have discovered that three-quarters of their samples were of the same pesticide suspected to be behind the decline of bee populations.
In total, the researchers analyzed 198 honey samples for five commonly used neonicotinoids: acetamiprid, clothianidin, imidacloprid, thiacloprid, and thiamethoxam. And indeed, spokespeople from multiple pesticide manufacturers refuted the study's claim that these levels would affect bee populations, and researchers from other institutions questioned the study's sweeping claims about neonics.
Joe Girardi on Yankees' Game 2 collapse: 'I screwed up'
Somehow, some way, Francona continues to make decisions that seem questionable from the outside but work out perfectly. Then the scoring stopped as the game inched on into night, past nine, 10, 11, and 12 innings.
In 2013, the European Union began a temporary ban on the use of three neonicotinoids on crops visited by bees, and is considering a comprehensive ban on the use of the pesticides in all outdoor fields. The total concentration of the five measured neonicotinoids was, on average, 1.8 nanograms per gram in contaminated samples and reached a maximum of 56 nanograms per gram.
The honey of North America was a dismal figure: the samples drawn from the continent were contaminated in 86% of cases, compared with 57 % of those from South America.
"I used to think of neonicotinoids as being a [localized] problem next to a small set of crops", says Amro Zayed, who studies bees at York University in Toronto and wasn't involved in the research. After finding that 34 per cent of the samples contained neonicotinoids harmful to bees, scientists warned that continued exposure to these chemicals could jeopardize the survival of bees. She wasn't part of the study.
Aebi said that he and the other researchers are especially concerned that so many samples contained two or more neonicotinoids. Mitchell's favorite is a dark and bitter honey from Africa.