Reports of experiments that exposed humans and monkeys to diesel fumes have the Volkswagen Group, Daimler and BMW scrambling to distance themselves from the situation.
The automakers are promising to investigate the tests whose disclosure now threatens to open a new phase in an emissions controversy that’s dogged the industry since 2015.
The study, conducted by the European Research Association for Environment and Health in the Transport Sector (EUGT), had 25 people expose themselves to diesel exhaust fumes at different concentrations and for several hours, the Stuttgarter Zeitung newspaper reported Monday.
The actions further undermine diesel’s image, steepening an uphill battle to rescue the technology amid worsening political headwinds.
“This is another hit for diesel and shows how carmakers overstepped the mark morally and ethically in their fight to make diesel socially acceptable,” said Stefan Bratzel, director of the Centre of Automotive Management in Bergisch Gladbach, Germany.
“This news means more pressure for politicians to act on diesel.”
At the weekend, the German automakers also confirmed that the EUGT researchers they commissioned used monkeys to test the health effects of inhaling diesel fumes.
The monkeys were exposed to the exhaust fumes of an older and a modern diesel vehicle, so the progress of the technology could be demonstrated.
The circumstances of the study, and details on how it was conducted, are contained in a sworn deposition of Jake McDonald, a scientist who oversaw the project.
McDonald said in the deposition, which was taken as part of diesel emissions suit filed against Volkswagen, that the monkeys were shown cartoons during hours of tests to help keep them calm.
“We believe that the scientific methods used to conduct the study were wrong and that it would have been better not to undertake it at all,” Volkswagen said in a statement on Monday.
“We are shocked by the extent and application of the studies … We condemn the experiments in the strongest terms,” carmaker Daimler wrote.
The German government also condemned the tests. ‘These tests … are in no ethical way justifiable and they raise many critical questions about those who are behind the tests,” said Steffen Seibert, a spokesman for German Chancellor Angela Merkel.