HAMBURG, Germany -- A German university teaching hospital that has been caught up in an outcry over testing the impact of nitrogen dioxide on humans said on Friday there was no danger to the people involved.
Aachen University's teaching hospital became embroiled in the saga after a German newspaper reported German carmarkers had sponsored scientific experiments testing nitrogen dioxide, a gas found in exhaust fumes, on the people.
The study was promoted by the European Research Group on Environment and Health in the Transport Sector, Stuttgarter Zeitung said.
The New York Times reported last month that Volkswagen, BMW and Daimler had also funded EUGT to commission separate tests on monkeys, which the Aachen team was not involved with.
Reuters could not confirm the details and purpose of the monkey study and EUGT, which was dissolved last year, could not be reached for comment.
The university team had already confirmed on Monday that EUGT had sponsored their human study in 2013 and 2014 but said it was related to workplace safety, not diesel emissions.
RWTH Aachen will pay more attention to the source of funding for such studies in the future, the university told a news conference on Friday.
As part of the study, 25 people were exposed to varying levels of nitrogen dioxide for three hours to investigate the possible health effects of the chemical compound in concentrations below the limit for workplaces, RWTH Aachen said its statement on Monday.
"The concentration of nitrogen oxide had been very low, not to harm the people being tested. We used very sensitive devices to detect possible respiratory reactions," Thomas Kraus, director of the institute, told the news conference on Friday.
"These are reactions of the immune system which can be measured with sensitive methodology, but which are far from a danger to a subject, because they are very quickly reversible ... There were no lasting changes."
Kraus, who specialises in occupational and environmental medicine, said "at the time, we had no idea" about the monkey testing.
"In hindsight it has to be said EUGT's behavior was problematic," he told reporters.
EUGT, created by Volkswagen, Daimler and BMW in 2007, was disbanded last year. The carmakers have since condemned EUGT's work and suspended employees who were working for the group.