The BioCrisis refers to a widespread environmental crisis prior to the events of Oni. At the time of Oni, the air supply in the cities is systematically filtered and decontaminated by ACCs. We learn from Dr. Hasegawa's diary that massive contaminated areas (called "Wilderness Preserves") exist outside the cities. One of these contaminated zones is the reason for the death of Jamie Hasegawa. Drs. Hasegawa and Kerr subsequently developed the Daodan project to help humans survive an impending danger from the BioCrisis. There is, in fact, evidence that the BioCrisis is still an ongoing event and a current threat, unbeknownst to the general populace.
The following console quotes shed only a little light on the nature of the BioCrisis:
The new systems modifications are designed to combat the steady rise in Class 3 atmospheric pollutants but the new parts have not been tested at full capacity. The second tier test will be followed by a test of the third tier, assuming everything goes according to plan.
ATMOSPHERIC INVERSION PROCESS TESTING
As a result the Class 3 toxins we are most concerned about would pass through the system untreated. There is even a chance that the they would be charged as they passed through the coupler transforming them into Class 4 airborne toxins.
ATMOSPHERIC INVERSION PROCESS TESTING [cont]
Needless to say the environmental damage in such an event would be catastrophic and irreversible. All crews must be aware of this danger and pay strict attention to the posted maintenance schedules and testing protocols.
All that we can glean from these consoles is that the pollutants are called "toxins", they are "airborne" (hence the Atmospheric Conversion Centers), and that there is a "steady rise" occurring in class 3 toxins. That last fact is the most significant.
There is one other console that mentions the nature of the pollution:
<<<Secondary Stage: COMPLETE>>>
STURMANDERUNG baseline report: Dioxin levels
Project initialization: 97 ppm
Primary stage: 100 ppm
Secondary stage: 152 ppm
The mention of dioxin, a cancer-causing chemical compound, seems to be merely a side effect of Muro's plan, the main purpose apparently being to trigger the inversion process mentioned above, wherein the class 3 toxins pass through the system untreated or are even elevated to class 4.
What exactly is the nature of the contamination of the outside world? Are all areas equally polluted? How did the the BioCrisis come about in the first place? These questions are not specifically answered in Oni. To tackle the last question first, the original pollution, for which the ACCs were developed, might have been merely the result of mankind's current habit of polluting Earth, progressed to a point that created a crisis. It remains to be seen in modern times whether we are winning or losing the battle against industrial pollution, but one could postulate that if some of our current habitual pollution was making things worse than we thought, it might be too late to reverse some damage when it was finally noticed. This is one possible explanation for the BioCrisis.
The other explanation is simply that there was a specific event such as a nuclear war or massive chemical reaction that caused the Crisis.
In either case, once the ACCs were built, people would have settled around them in cities. A BioCrisis Subcommittee was dedicated to monitoring the status of the pollution and augmenting the efficiency of the ACCs. Hasegawa's diary makes it clear that ACCs did not cover the entire inhabited earth ("The world outside the Atmospheric Processors is poisonous"). Oddly, he calls the place he and Jamie go "one of the Contaminated Zones, the dirty secrets that the government made it easy to ignore." Wouldn't the general populace be well aware of the fact that the world outside the ACCs is polluted? Isn't that why they're living under the shadow of the ACCs?
This means that Hasegawa had learned that either (a) there were specific zones that were much worse than people realized, or (b) the entire world outside the ACCs was worse than people realized. Hasegawa does not make it clear whether the Zones were isolated areas, or whether every area outside the reach of the ACCs was this way. He simply says that he and Jamie 'left the city' that was being cleansed by an ACC.
If "a" is the case, then it is possible that highly concentrated waste produced during the ACCs' decontamination process was being improperly disposed of. This would have resulted in a highly contaminated soil ("a poisonous world") wherever that waste was dumped. (Hasegawa's description of a typical Wilderness Preserve (for what it's worth ^_^) is reminiscent of Miyazaki's Nausicaa.)
We also get the impression that the WCG is rather complacent about cleansing the rest of the earth outside the cities. Perhaps they have been telling people that they are doing so, when in fact things are pretty dangerous out there (possibility "b"). Why is the WCG not struggling to fix the planet? The reason could be as innocuous as the fact that such cleanup work is actually too costly for anyone to perform, even a world government; the reason might be more sinister, too, such as the fact that it is easier to monitor and control a population when they bunch up in cities than when they are spread throughout the countryside.
It's interesting to note that, as far as most people know, their lives within the cities are sustainable. As long as the ACCs keep pumping out clean air, everything will be fine. Hasegawa, after losing Jamie to a Contaminated Zone, feels differently, because he says "If something isn't done we are all doomed."
The entry that we hear from his diary is unfortunately not clear on why humanity is doomed. Did Dr. Hasegawa observe the "steady rise in class 3 pollutants"? Did he predict that the hostile wildlife of the Wilderness Preserves would take over the cities at some point? Perhaps the ACCs are not keeping up with the pollution outside, or perhaps the pollution is still growing.
We still have not addressed the first question this section raised, about the nature of the pollution. There are three basic possibilities as to what this pollution is:
- Basic toxins, infusing the flora such as the plant that kills Jamie with a mere scrape on the leg.
- Advanced biological agents such as powerful viruses, perhaps mutated by the original pollution.
- Alien life invading our ecosphere.
If #1 is the case, then something must be continuing to pollute the earth. Poisons do not multiply themselves, so as long as things such as runoff from polluted soil and toxic rain were not allowed to enter the city, then the way of life in those cities would be sustainable and not at all doomed. Is there an ongoing industrial or organic process that is making more pollutants?
Perhaps #2 is the case, and the WCG is using the word "toxin" to avoid panic if people are aware of the true nature of the threat. Certainly it is easier to understand how, rather than inert toxins, living, virulent organisms might be in the process of spreading and invading the cities. They could be mutated viruses created by some original pollution.
The third option above may seem much more far-fetched, but there is a mention of extraterrestrial life in the description of the Screaming Cell Cannon. Where are the Screaming Cells coming from? Is it possible they are are being harvested from the Contaminated Zones? The infection that kills Jamie could well be some lifeform that is not of this earth. Any further conclusions cannot be reached from the facts that Oni gives us, leaving the rest to our imaginations to fill in.