Reports by German newspapers Stuttgarter Zeitung and Süddeutsche Zeitung said humans had been exposed to a gas found in diesel fumes during an experiment "sometime between 2012 and 2015" requested by a group funded by German carmakers.

The tests were requested by the European Research Group on Environment and Health in the Transport Sector (EUGT) — a now defunct organization founded by German carmakers Volkswagen, Daimler and BMW.

Read more: German university hospital defends auto firms' nitrogen dioxide test ethics

The experiments focused on "short-term nitrogen dioxide inhalation by healthy people," according to the newspapers. An Aachen-based university hospital then examined 25 people after they inhaled varying amounts of the gas over several hours.

The experiments were reported on after recent revelations of an experiment where — in equally controversial tests — monkeys were made to inhale the toxic gas.

Watch video 01:35 Share Carmakers used humans for gas test Send Facebook google+ Whatsapp Tumblr linkedin stumble Digg reddit Newsvine Permalink https://p.dw.com/p/2rhmB Carmakers used humans for gas test

Not to be tolerated

Reacting to the accusations, Volkswagen said in a statement "we are convinced that the scientific methods chosen at the time were wrong."

Daimler said Sunday it was "shocked by the extent of those studies and the way there were carried out."

"We strongly condemn the tests," the company said, adding that it had had no say in the testing method and the measures taken by the EUGT were "against Daimler's values and ethical principles."

The Stuttgart-based carmaker said it had launched an investigation into the tests on monkeys and humans which it considered "superfluous and repulsive."

German Environment Minister Barbara Hendricks said later on Monday she was "horrified" by the news.

"What is known so far is disgusting," she said, adding that the auto industry and the scientific community must explain their role. "The fact that an entire industry has apparently tried to conceal brazen and dubious methods of scientific research makes it even more monstrous."

Read more:Opinion: Car industry going from bad to worse?

Germans and their cars Mobility made in Germany The reputation of Germany's famed carmakers may have taken a hit, but their sales still soar. Yet German brands make up less than two-thirds of all cars on German roads, which is still a male-dominated territory: Only one-third of all owners in 2017 were women. Interestingly, that number has virtually not changed over the past decade.

Germans and their cars A decade on the road German passenger vehicles, are growing steadily older, from 8.1 years a decade ago to 9.3 years in 2017, the highest-ever age. By the way: By no means is Germany the car capital of the world: It ranks 20th in motor vehicles per capita - 17 spots behind the US, where every 10 people own eight cars. The world's least motorized country? Togo.

Germans and their cars Land of the vintage automobile Roughly 600,000 vehicles - 13 percent of all cars on German roads - are considered vintage cars which means they are more than three decades old. 380,000 have a historic license plate, which requires the vehicle to be in "contemporary, original preservable condition."

Germans and their cars Steady motorization As of January 1, 2017, 45.8 million passenger vehicles were registered in Germany. Based on a population of 82.8 million, it translates to 684 cars per 1,000 people. Today, there are five times as many cars in Germany than there were half a century ago when roughly 9 million vehicles drove on the "Autobahn."

Germans and their cars BMW country is king The average passenger vehicle age in Germany varies from state to state. Maybe not surprisingly, cars in Bavaria, the home of BMW and the state with the highest economic per capita output, are the youngest at nine years, while the average vehicle on Brandenburg's roads, the state surrounding Berlin, is almost a decade old.

Germans and their cars Germany lags behind While the number of gasoline-powered cars have remained remarkably stable over the past decade, their share steadily decreased to two-thirds of all engines in 2017. The number of diesel cars has risen from 10 to 15 million since 2008. Electric and hybrid cars combined made up 200,000 of all 45 million - that's 0.5 percent. In Norway, the share of electric vehicles alone is more than 1 percent. Author: Benjamin Bathke



An occupational hazard

Aachen University Hospital said in a statement that the aim of the study was to examine whether exposure to NO2 at various concentrations below the previous limit would result in biological effects in healthy volunteers.

"The study thus served to optimize job security, for example for truck drivers, vehicle mechanics and welders," the statement read. "Extremely sensitive, non-invasive techniques were used to capture the biological response, in line with the best available methodology and based on years of development work."

hg/jd (dpa, Reuters)