Microplastics in rivers make sewage dumps more toxic

A DANGEROUS cleaning chemical can hitch a ride on microplastics and be eaten by wildlife, making sewage overflows more toxic than previously thought, a study suggests.

Scientists at the University of Birmingham found that a common detergent in laundry products and spray cleaners binds to plastic in a “Trojan horse effect” that makes it easier for tiny water creatures to ingest it.

Intake by animals at the bottom of the food chain has a knock-on effect for other river life, and may lead to human consumption of plastics and chemicals.

The team looked at how the common plastic polyethylene interacted with chemicals known to be present in sewage discharge in Britain’s waterways.

They found that one chemical, sodium dodecyl sulphate (SDS), was more toxic to water fleas when combined with microplastics.

Researchers believe that SDS coats the plastic which is then ingested by the fleas which mistake it for food, leading to greater uptake of the chemical than when it is in the water alone.

SDS is harmful to aquatic life as it breaks down creatures’ cell membranes, while microplastics become lodged in the gut, leading to starvation.

Speaking at the British Science Festival in Leicester, Dr Katie Reilly, of the University of Birmingham, said: “We are already all very concerned about untreated sewage flowing into rivers… but this research suggests it may be having a really harmful effect on the environment, by releasing chemicals which are made more toxic by plastic.”