Datugad's surface was the home of a native population. The civilization was neither wealthy, nor extremely populous, when compared to other Federation worlds, according to Admiral Patterson of the Starfleet Surgeon General's office.
While they had, by the 23rd century, attained global unity and a secular government, the Datugad peoples' spiritual history was domination by a degree of religion and superstition, with the government at that late date still feeling pressure to bow to the demand of powerful religious sects, including the dominant Essejjian movement who followed the teachings of a spiritual figure named Essejj.
Datugad was eventually in contact with other local quadrant states, including the Federation. By the 23rd century, Datugad was a leading producer of trimanium ore, which was of high value as an alternative energy source that could be used to conserve dilithium.
The planet Datugad was strip mined and new chemical processing methods were created by the natives in their zeal to maximize production of the valuable export. Eventually, by-products spread throughought the ground, water and atmosphere, saturating all lifeforms on the world.
As the native life became poisoned with chemical saturation, a new side-effect emerged with the humanoid natives. Any two Datugad residents who came into close contact began a chemical reaction that caused spontaneous incineration, preventing sexual reproduction and even common contact among the inhabitants. Efforts to preserve the species also failed as new births became victims of the effect as they were poisoned during incubation.
The Federation, concerned at their part in the disaster as the leading buyers of trimanium, intervened with an ambitious Starfleet Medical project to move the species to another planet by means of artificial fertilization. Genetic material would be collected and purified of the contaminants before being artificially gestated. Upon birth, the new population would be raised and taught their native language and culture on a colony planet, where the species would live on after the quarantine of Datugad and the death of the homeworld's entire population.
To expedite the medical project, the starship USS Enterprise-A visited Datugad to deliver a Federation medical team to begin the revivication project. Because of religious protests near the landing party site, a security team from the Enterprise-A crew was sent along also. When the Essejjians, under religious leader Shelm, took the Federation teams hostage, an unauthorized shuttle landing of Starfleet personnel ended the standoff after Shelm's own monstrous actions in Essejj's defense convinced Shelm's followers to turn on him and free the hostages. (TOS comic: "So Near the Touch")