In experiments conducted between 2003 and 2010 and funded by the US Environmental Protection Agency, children as young as 10 years of age were exposed to diesel exhaust, despite well-established warnings against diesel exposure.

An advocacy group called the Energy and Environmental Legal Institute obtained documentation of the experiments through the Freedom of Information Act.

The experiments were conducted by researchers working for two of the more prestigious universities in the US, the University of Southern California and the University of California at Los Angeles. Researchers sprayed diesel exhaust particles into the nostrils of 20 children, aged between 10 and 15 years old, according to the experiment documents, and monitoring the effects.

“Not only has EPA been caught violating the letter and spirit of virtually every national and international code, law and regulation for the protection of human subjects in medical experiments developed since World War II,” E&E lawyer David Schnare said in a statement. “But they have done so in shocking style, abusing the most vulnerable people of all, children.”

According to public documents from UCLA, the purpose of the study was to compare the ability of adults and children in producing natural chemicals – antioxidants – that protect against pollution. The highest level of diesel particles any of the children were exposed to is equivalent to two days average urban exposure in Los Angeles.

The EPA didn’t respond to calls for comment on the experiments.

“Compounding the basic villainy of the experimentation itself is that the USC/UCLA researchers failed to warn the parents and children how dangerous EPA and CARB had determined diesel exhaust to be,” Mr Schnare said. “So there was no informed consent as required by law.”

Both Mr Schnare and Committee for a Constructive Tomorrow Executive Director Craig Rucker have asked US Congress and law enforcement officials to investigate the experiment. Neither group has given any indication that they will investigate.