alt Hacker Newsgreat questionprobably not poison it directly, but you'd lose a significant chunk to oxidation reactions before reaching any stable equilibrium. the surface is essentially a massive reactive sink. mars has a similar problem, the perchlorate in the soil would react badly with a lot of things we'd want to introduce. the optimistic read is that oxidation reactions release energy and eventually reach stability. the pessimistic read is the timescale is geological.
Isn't Mars red due to oxygenation of the rocks? Is that ancient oxygenation or is there some quantity of oxygen in Mars atmosphere today? Does the atmospheric CO2 sometimes break down (maybe under sunlight) and release some small quantity of O2 or might there be another source? Might something underground be respirating atmospheric CO2?