Mankind lives in an uneasy peace with the poisons he has developed. Some of them, such as lead spewed into the air by cars burning leaded fuels or the chloride compounds eating into the ozone layer, seem innocuous until a buildup occurs. Others, such as tankers of acid or jars of caustic lye, are labeled as poisons and treated accordingly. These poisons, stored in bulk where they are manufactured or by the industries that use them, will explode during the massive earthquakes the cataclysms bring, and spread worldwide by the hurricane force winds. Add to this the stores of nuclear bombs, stockpiled during the cold war, which might be triggered during earthquakes, or leak radiation as would damaged nuclear power plants. How livable will the Earth be, after the cataclysms, when mankind will find all his poisons have spilled in his backyard?
Several factors will be at play during the cataclysms that are not in place during normal times, and these factors change the picture.
Note: below added during the Dec 21, 2002 Live ZetaTalk IRC Session.
Pollution can be viewed from several angles. The bottle of chlorine, considered poison, if poured in a pool will create havoc, but this is a local reaction. Some pollution, like PCB's, that are long lived and continuously effect, anew, whatever they contact, are more than a single pollutant, they are an endless pollutant, or so to speak. But others engage in chemical reactions, and thus are self limited. Some heavy metals also effect the area only for a short time, then go where heavy metals do, get buried, or trapped in a chemical bond, to be where they were when mankind first discovered them and engaged them in industrial uses. Thus, when mankind looks upon industrial poisons, maintained in tanks, they assume a permanent cesspool, but this is not always the case. Were the contents of all these tanks to mix, there would be gasses, explosions, and eventually the mix returns to what nature does with these chemicals in the first place.
The cave man found the Earth in a state, and this state would be achieved in short order if all the poisons in tanks were left to mix freely. Even radioactivity is only a poison because mankind gathered it together, and if allowed to disburse, would be as the cave man found it. Thus, where we are advising that mankind not linger about industrial sites for the shift, nor settle there afterwards, this is not to say that these poisons will retain their impact for long. Especially where not trapped in small pools, and by this we mean pools, not lakes. Try an experiment. Take the chemicals you fear, that exist in your local industrial park, and mix them together in a fish tank. This must be proportional to the nearby lake or river, to be properly diluted. Add fish, and see what happens! You may be surprised to find that your chemicals, combined, reduce each other's impact! These noxious chemicals were once non-noxious, in nature, and find their way there again.