The world’s most widely used insecticides pose a serious danger to both honeybees and wild bees, according to a major new assessment from the European Union’s scientific risk assessors.

The conclusion, based on analysis of more than 1,500 studies, makes it highly likely that the neonicotinoid pesticides will be banned from all fields across the EU when nations vote on the issue next month.

The report from the European Food Safety Authority (Efsa), published on Wednesday, found that the risk to bees varied depending on the crop and exposure route, but that “for all the outdoor uses, there was at least one aspect of the assessment indicating a high risk.” Neonicotinoids, which are nerve agents, have been shown to cause a wide range of harm to bees, such as damaging memory and reducing queen numbers.

Jose Tarazona, head of Efsa’s pesticides unit, said: “The availability of such a substantial amount of data has enabled us to produce very detailed conclusions. There is variability in the conclusions [and] some low risks have been identified, but overall the risk to the three types of bees we have assessed is confirmed.”

The Efsa assessment includes bumblebees and solitary bees for the first time. It also identified that high risk to bees comes not from neonicotinoid use on non-flowering crops such as wheat, but from wider contamination of the soil and water which leads to the pesticides appearing in wildflowers or succeeding crops. A recent study of honey samples revealed global contamination by neonicotinoids.

The assessment was welcomed by many scientists and environmentalists. “This is an important announcement that most uses of neonicotinoids are a risk to all bee species,” said Prof Christopher Connolly, at the University of Dundee, UK. “The greatest risk to bees is from chronic exposure due to its persistence.” Prof Dave Goulson, at the University of Sussex, said: “This report certainly strengthens the case for further restrictions on neonicotinoid use across Europe”.

“We have been playing Russian roulette with the future of our bees for far too long,” said Sandra Bell at Friends of the Earth. “EU countries must now back a tougher ban.” Several nations had been waiting for the Efsa report before deciding their position.

However, a spokesman for Syngenta, a neonicotinoid manufacturer, said: “Efsa sadly continues to rely on a [bee risk guidance] document that is overly conservative, extremely impractical and would lead to a ban of most if not all insecticides, including organic products.”

Matt Shardlow, at charity Buglife, said the risk guidance document should be urgently implemented to prevent another pesticide “blunder”. He said: “It is a tragedy that our bees, moths, butterflies and flies have been hammered by these toxins for over 15 years.”

In March 2017, the Guardian revealed draft regulations from the European commission which would ban neonicotinoids from all fields across Europe, citing “high acute risks to bees”. The chemicals could still be used in closed greenhouses.

Efsa’s first assessment in January 2013 found “unacceptable” risks to bees from neonicotinoids and paved the way for the partial EU ban which was passed in April 2013. It banned the use of the three main neonicotinoids on flowering crops, principally oilseed rape, as they were seen as most attractive to bees.

Bees and other insects are vital for global food production as they pollinate three-quarters of all crops. The plummeting numbers of pollinators in recent years has been blamed on disease, destruction of flower-rich habitat and, increasingly, the widespread use of neonicotinoid pesticides.

Pesticides damage survival of bee colonies, landmark study shows Read more

There has been strong evidence that neonicotinoids harm individual bees for some years but this has strengthened in the last year recently to show damage to colonies of bees. Other research has also revealed that 75% of all flying insects have disappeared in Germany and probably much further afield, prompting warnings of “ecological armageddon”.

In November, environment secretary Michael Gove overturned the UK’s previous opposition to tougher restrictions on neonicotinoids. “The weight of evidence now shows the risks neonicotinoids pose to our environment, particularly to the bees and other pollinators which play such a key part in our £100bn food industry, is greater than previously understood,” Gove told the Guardian. “I believe this justifies further restrictions on their use. We cannot afford to put our pollinator populations at risk.”

The environment department’s chief scientist, Prof Ian Boyd, warned in September that the assumption by regulators around the world that it is safe to use pesticides at industrial scales across landscapes is false. This followed other highly critical reports on pesticides, including research showing most farmers could slash their pesticide use without losses and a UN report that denounced the “myth” that pesticides are necessary to feed the world.