The city of Philadelphia has apologized for unethical medical experiments performed on Black inmates at Holmesburg Prison for over 20 years, reports CNN.

From 1951 through 1974, Dr. Albert Kligman, a dermatologist from the University of Pennsylvania, conducted “the dermatological, biochemical and pharmaceutical experiments that intentionally exposed about 300 inmates to viruses, fungus, asbestos and chemical agents including dioxin—a component of Agent Orange.” 

According to the report, Kligman's experiments were performed on Black men who were awaiting trial and trying to save money for bail. Many of them were illiterate.

In his experiments, Kligman intentionally infected the inmates with ringworm and forcibly removed the subjects’ thumbnails. The horrific experiments left inmates wounded and many did not receive proper medical care. For their participation in the experiments, the inmates were paid $1 a day.

Companies such as Johnson & Johnson, Dow Chemicals and even the U.S. Army were just some of the many sponsors who underwrote the project.

Philadelphia Mayor Jim Kenney said that an apology was in order because the experiments exploited a vulnerable population and contributed to the legacy of medical racism that still exists.

"Without excuse, we formally and officially extend a sincere apology to those who were subjected to this inhumane and horrific abuse,” Kenney wrote. “We are also sorry it took far too long to hear these words.”

“Recognizing the deep distrust experiments like this have created in our communities of color, we vow to continue to fight the inequities and disparities that continue to this day,” his statement continued.

In response to the discovery, the University of Pennsylvania issued a formal apology and removed Kligman’s name from its annual lecture series and a professorship last year.

The university also redirected research funds to fellows whose work centered on dermatological issues in people of color.