Public criticism of the German auto industry has escalated after reports that diesel exhaust tests were carried out on both monkeys and humans.
Public criticism of the German auto industry has escalated after a report that an industry-sponsored entity commissioned a study of the effects of diesel exhaust using monkeys, while another study exposed humans to low levels of one type of air pollutant.
The German government said on Monday such studies were unjustifiable. The tests were reportedly commissioned by a research group funded by major German auto companies.
Volkswagen sought to distance itself from them, with its chairman saying that "in the name of the whole board I emphatically disavow such practices."
Volkswagen's supervisory board called for an immediate inquiry into who commissioned tests in which monkeys were exposed to toxic diesel fumes.
"I will do everything possible to ensure that this matter is investigated in detail," Volkswagen supervisory board Chairman Hans Dieter Poetsch said in a statement on Monday.
"Whoever is responsible for this must of course be held accountable," Poetsch said in response to a New York Times report on Friday that German carmakers had used an organisation called European Research Group on Environment and Health in the Transport Sector (EUGT) to commission the tests.
The study, conducted in 2014, was designed to defend diesel following revelations that the fuel's exhaust fumes were carcinogenic, the newspaper reported.
Reuters could not immediately confirm the details and purpose of the study and EUGT, which was dissolved last year, could not be reached for comment.
EUGT received all of its funding from VW and fellow German carmakers Daimler and BMW, the New York Times said.
The New York Times report found that the research group financed by top German car manufacturers commissioned experiments in which one group of monkeys was exposed to diesel exhaust from a late-model Volkswagen, while another group was exposed to fumes from an older Ford pickup.
The experiments were carried out before Volkswagen was caught using software that let vehicles cheat on emissions tests.
They were intended to show modern diesel technology had solved the problem of excess emissions, but according to the Times report the Volkswagen car in the tests was equipped with illegal software that turned emissions controls on while the car was on test stands and off during regular driving.
Volkswagen admitted using the software in 2015. The Volkswagen scandal led to public scrutiny of diesel emissions as regulators discovered that other companies' vehicles also had higher emissions on the road than during testing, though not necessarily through illegal rigging.
The industry has had to fend off calls for diesel bans in German cities with high pollution levels.
Daimler AG said it was "appalled by the nature and extent of the studies" and said that, though it didn't have any influence on the studies' design, "we have launched a comprehensive investigation into the matter."
BMW said that it "did not participate in the mentioned study" on animals "and distances itself from this study." It said it was investigating the work and background of the research group.
The Times report was followed by one in Monday's edition of the Stuttgarter Zeitung daily that the now-closed research group also commissioned tests in which humans were exposed to nitrogen dioxide, which belongs to a class of pollutants known as nitrogen oxides. The group reportedly said the tests showed no effect on the subjects.
'No ethical justification'
The human study, carried out by Aachen University, involved studying the effects of exposing 25 subjects, mostly students, to low levels of nitrogen dioxide like those that could be found in the environment — from a 40-litre bottle, not a diesel engine. The individuals gave informed written consent for the study, which was approved by the ethics committee of the university's medical faculty, according to the study. The university said the study had no relation to the diesel scandal.
The German government condemned the reported tests on animals and humans. Transport Minister Christian Schmidt "has no understanding for such tests ... that do not serve science but merely PR aims," spokesman Ingo Strater told reporters in Berlin.
Chancellor Angela Merkel's spokesman, Steffen Seibert, said that "the disgust many people are feeling is absolutely understandable."
"These tests on monkeys or even humans can in no way be ethically justified," Seibert said. "They raise many critical questions for those behind these tests, and these questions must urgently be answered."
He questioned the aims of the tests. "The automakers have to reduce emissions of harmful substances further and further," he said. "They should not be trying to prove the supposed harmlessness of exhaust with the help of monkeys or even humans."
Seibert said that the supervisory boards of the companies concerned "have a particular responsibility."