Up to 29 times more potentially carcinogenic particulate matter is emitted by refrigeration vehicles than by modern modern Euro 6 diesel truck engines, according to the findings of a new study. 

Carried out by cold technology firm Dearman, the research specified that the 84,000 transport refrigeration units on UK roads emit up to 49,125 tonnes of CO2, 163 tonnes of NOx and 22 tonnes of particulate matter onto the streets of London every year. 

The machines are primarily diesel powered and currently unregulated, prompting Dearman to call on the government to step in and legislating for units in London to be made zero emission. 

It is argued by the company that this action would be the equivalent of taking 327,510 diesel cars off the city's streets.

Dearman international ambassador Dr Tim Fox said: "Although refrigerated vehicles make up a small proportion of the vehicles on the road, they are unregulated, use out-dated fossil fuelled technology and are disproportionately polluting."