According to rumor, people who eat contaminated food will get very sick. Since this toxic substance is a mutagen, they will also change into a monster.
So the story goes in Sumaru City. Worse, the rumor has begun to change, twisting into a story that it can even be passed casually from person to person. Fortunately, there is a cure. As rumor also would have it.
For the general population, the path of the debilitating illness has been plain: born by the polluted waters, it contaminated anything it touched, especially fish and other marine life. From there, it seems that even being in contact with the already ill is enough to spread the sickness further.
The reality of the situation is much more complicated. The exact source of the panic remains a mystery, but some can trace it back to a sighting of a 'black tarry substance' on site in Inaba and the shores of Tatsumi Port Island. From there, it's uncertain if it's merely rumor that sent the story of pollution and illness cycling forth, or if something else was at play.
The symptoms are fairly plain but distressing for those who fall sick. There are aches and pains, a persistent cough, extreme exhaustion, and often a fever. Those afflicted tend to not want to move.
As the rumor goes, those who fall ill become sicker and sicker until they inevitably mutate. At that point, they turn into monsters. The shape, form, and mind of the monstrous state seems to vary on the person; there is no joint characteristic known.
The mutated form gives them greater strength than usual, but their shape is never one suited for the public. For those who succumb mentally as well, they may revert to animalistic impulses.
The transformation into a monster can be halted, staved off, or cured by a dosage of Cintamani, an unregulated street drug. Those who have changed revert to normal shortly after a dose of the drug.