Diesel emissions are ‘50pc higher than if laws were being obeyed’

DIESEL cars are pumping out 50 per cent more toxic emissions than they should be if all were complying with pollution laws, researchers have found.

In Europe the failure to meet emissions standards could be leading to the deaths of 11,500 people every year, warns a new report by the University of York and the International Council on Clean Transportation .

Between 2008 and 2015 Volkswagen rigged diesel cars so they could pass stringent environmental tests while emitting dangerous levels of pollution.

But until now it was unclear if other car companies had fitted similar “defeat devices”. The new research concluded that diesels are emitting far more nitrogen oxides than they should for reasons which could range from “engine calibration to equipment failure, inadequate maintenance, tampering by vehicle owners, the deliberate use of defeat devices, or simply deficient certification test procedures”.

Roy Harrison, professor of environmental health at the University of Birmingham, said: “This is a rigorous study which highlights the serious consequences which have resulted directly from the irresponsible actions of the motor manufacturers in producing vehicles which meet regulatory requirements under test conditions, but emit far higher pollutant levels during on-road use.

“The study may well underestimate the full consequences for public health as it quantifies only the effects of particulate matter and ozone formed in the atmosphere as a result of excess nitrogen oxides emissions, but not the direct effects of the oxides of nitrogen themselves.”

Nitrogen oxide is a key contributor to outdoor air pollution. Long-term exposure to these pollutants is linked to a range of adverse health outcomes, including disability and reduced life expectancy due to stroke, heart disease, chronic obstructive pulmonary disease, and lung cancer.

The High Court recently ruled that the Department for the Environment must produce a plan to tackle air pollution in British cities which regularly breach safe air levels. For the new diesel report, published in Nature, researchers analysed data from 30 studies of vehicle emissions under realworld driving conditions around the world.

They found that vehicles emitted 13.2million tons of nitrogen oxide under real-world driving conditions, which is 4.6million tons more than expected under official laboratory tests.

Josh Miller, a researcher at the International Council on Clean Transportation, said: “For light-duty vehicles, such as passenger cars, trucks, and vans, the European Union produced nearly 70 per cent of the excess diesel nitrogen oxide emissions.”

At a global level, the study estimates that the impact of all real-world diesel nitrogen oxide emissions could grow to 183,600 early deaths in 2040.

‘This highlights the serious consequences which have resulted from irresponsible actions of manufacturers’