Pesticides that harm bees are found in most English waterways.

Bee-harming pesticides were found in the “majority” of English waterways tested last year, according to an analysis of data by two environmental charities.

The Rivers Trust and Wildlife and Countryside Link found that neonicotinoid pesticides were present in 85% of English rivers tested by the Environment Agency between 2023 and 2024.

There was a banned pesticide. Signed for emergency use by the previous government. to deal with a disease affecting sugar beet crops – a decision which the Department for Environment, Food and Rural Affairs (Defra) is now investigating.

On Monday, the government pledged to “ban the use of neocotinoid pesticides that threaten bees and other important pollinators.”

The Office for Environmental Protection is currently investigating Defra’s emergency authorization for the use of a type of neonicotinoid on sugar beet seeds in 2023 and 2024.

The watchdog is investigating whether the government failed to comply with environmental laws when it allowed the use of a previously banned pesticide.

Neonicotinoids are a group of pesticides used to control pests in agriculture, horticulture and veterinary medicine – but they also harm bees and other beneficial insects.

They are currently used by sugar beet growers to protect their crops from virus yellows, a disease spread by aphids.

In March, Dan Green, director of agriculture at British Sugar, said the pesticide was needed “to protect the UK’s sugar beet crop and farmers’ livelihoods”.

But environmental charities are calling on the government to “enforce and extend” the ban on neonicotinoid use to protect plant and animal health. Charities are also calling for better monitoring of the river by the agency.

Dr Richard Gill, principle researcher at Imperial College, said that while high doses of neonicotinoids can kill bees, even small doses can have “cumulative, sub-lethal” effects on pollinators, changing their behaviour. are and can even affect their genes.

Bees under the influence of neonicotinoids may struggle to fly and “seem to bring back less pollen” to their hives, Dr Gill said.

The latest analysis of Environment Agency data comes against a backdrop of declining bee populations across the country.

Dr Gill said a number of factors – including changes in agricultural land use, urbanisation, the effects of climate change, pesticide use and emerging pathogens – meant that many bee species were “not doing very well”. doing”.

“It’s concerning that we’re getting these pesticides in rivers,” Dr. Gill said, adding that it’s important to monitor concentrations of chemicals in waterways.

Amy Fairman of the River Action campaign group said agricultural waste was responsible for more water pollution in the UK than sewage.

Although their effects on bees are widely recognized, neonicotinoids also harm marine ecosystems, including riverine insects, he said.

“River worms are at the bottom of the food chain,” he told BBC News. “If we’re destroying the bottom of the food chain in our rivers, it’s going to have a knock-on effect.”

The chemicals are also “particularly dangerous to human health,” Ms. Fairman said.

He advised that people considering swimming in polluted rivers should “understand the level of contamination” and “educate” themselves about the risks before entering the water.

The latest analysis shows that levels of neonicotinoids have increased slightly compared to previous years.

The Rivers Trust and Wildlife and Countryside Link point out that its analysis is based on a small sample of data provided by the Environment Agency.

Charities are calling for more comprehensive river monitoring by the regulator after only a small fraction of the country’s river sites were tested for neonicotinoids last year.

At the Labor Party conference in September, Environment Secretary Steve Reid pledged to “restore nature and stop animal waste, fertilizers and pesticides from entering our waterways.”

On Monday, a Defra spokesman said the department was “committed to tackling all sources of pollution to clean up our rivers, lakes and seas”.

“This government has made it clear that we will change current policies to ban the use of neonicotinoid pesticides that threaten bees and other important pollinators.”

The Environment Agency said its testing was “specifically targeted at sites where we want to better understand the chemical risk and any measures required to protect the environment”.