PARIS • "Excess" diesel truck and car emissions claimed about 38,000 lives worldwide in 2015, revealed a study that sought to quantify deaths due to pollution that carmakers sought to hide.
Four-fifths of these additional premature deaths due to nitrogen oxide (NOx) pollution occurred in three regions - the European Union, China and India, reported researchers in the journal Nature.
NOx are poisonous gases that contribute to acid rain and combine with ammonia to create particles that can penetrate deep into the lungs and cause cancer, chronic breathing problems and premature death.
Until recently, estimates of deaths attributable to NOx pollution were based on levels reported by vehicle makers. But since 2015, it has become clear that Volkswagen and other manufacturers used "defeat devices" to disguise the true extent of diesel engine emissions, which are far higher on the road than in laboratory testing.
The new study of 11 major car markets - the others are Australia, Brazil, Canada, Japan, Mexico, Russia, South Korea and the United States - revealed that diesel vehicles spewed at least 50 per cent more NOx under actual driving conditions than their makers claimed.
That translates to 38,000 deaths due to excess emissions, out of an estimated total of 107,000 lives foreshortened due to diesel car and truck fumes in 2015.
China suffers the greatest health impact, with 31,400 deaths annually attributed to diesel NOx pollution. Of those deaths, 10,700 were linked to excess NOx emissions beyond certification limits, said the report. Long-term exposure is linked to disability and premature death due to stroke, heart disease, lung cancer and chronic obstructive pulmonary disease. The elderly are especially vulnerable.
Commercial trucks and buses are by far the biggest culprit globally, accounting for more than three-quarters of excess NOx output.
An earlier study calculated that pollution from 2.6 million Volkswagen cars equipped with test-evading software and sold in Germany from 2008 to 2015 will cause over 1,200 premature deaths in Europe.
But defeat devices are not the only cause of additional NOx emissions, showed the new research. Others included faulty engine calibration, poor maintenance, tampering by vehicle owners and sub-standard certification testing.
AGENCE FRANCE-PRESSE, XINHUA