The honey analyses, published in the journal Science, began as a citizen science project when researchers at the Botanical Garden of Neuchâtel, Switzerland, asked people to donate honey collected from around the world between 2012 and 2016. "The findings are alarming, neonicotinoids have become so globally ubiquitous that they are now present in 75 per cent of all honey", said Chris Connolly from the University of Dundee, who was not involved in the research.
In France, the neonicotinoids have been banned.
Jeffrey Donald, a spokesman for Bayer Crop Science which makes the neonic clothianidinsaid, said the study "perpetuates the myth that exposure to low levels of neonicotinoids implies risk, even though there is no compelling scientific evidence to support this conclusion". Further research is needed to gauge the effectiveness of the European Union steps. Because honey bees do not produce honey.
To test contamination levels, samples of honey were taken from local producers worldwide, and researchers tested for five commonly used neonicotinoids: acetamiprid, clothianidin, imidacloprid, thiacloprid, and thiamethoxam. Neonics work by attacking an insect's central nervous system. "On these contaminated samples, 45 % contained at least two, and 10 % four or five ".
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. The results suggest that a substantial proportion of world pollinators are probably affected by neonicotinoids.
"[The] average concentration [found in the honey] lies within the bioactive range, causing deficits in learning, behaviour, and colony performance".
The scientists say the chemical is not near levels that would come close to harming humans, but it is a big worry for bees.
"The severity of the global threat to all wild pollinators from neonicotinoids is not completely clear from this study, because we don't know how the levels measured in honey relate to actual levels in nectar and pollen that wild pollinators are exposed to", she said.
"Chronic infections, such as those found in long-lasting wounds comprise about 60-80 per cent of infectious diseases in humans and the way fungi invade wounds is associated with the use of broad-spectrum antibiotics", Alhindi said.