London’s residential neighbourhoods are being choked by “secret pollution” emitted by trucks delivering chilled food to the new generation of local supermarket convenience stores, according to a report.
Many of the hundreds of daily deliveries of fresh fruit, vegetables, meat and fish to the supermarkets are made by small lorries using diesel-powered transport refrigeration units (TRUs).
However, the largely unregulated motors that power them are belching out huge quantities of dangerous particulates and nitrogen dioxide gases, according to the study by London technology company Dearman.
Its research has found that TRUs give out 164 times more particulates — the microscopic sooty flakes that are a by-product of burning diesel —than a diesel car.
There are estimated to be 84,000 TRUs in Britain, many used by the big supermarkets and chains such as coffee shops that sell chilled food. Many home deliveries by the likes of Ocado and Tesco.com use vans with TRUs but these are usually run off the vehicle’s engine rather than a separate unit.
Dr Tim Fox, former head of energy and environment at the Institution of Mechanical Engineers, and a global ambassador to Dearman, said: “TRUs are hidden polluters that are coming into these residential areas and pumping out significant amounts of NOX and particulates.
Their use has increased as a result of the increased demand for chilled and frozen products and the increased interest in artisan and fresh food available locally. A lack of regulation has been a feature of this area of technology, they sweep in under the radar.”
Dearman, which has bases in Covent Garden and Croydon, is working on an alternative “clean” system using liquid nitrogen to chill food. It estimates that converting all TRUs to the zero-emission technology would take the equivalent of 5.5 million diesel cars and 500,000 trucks off the road.