Description of change to the ecosystem during hurricane katrina?

In the early days after Katrina hit and the levees broke, there were fears that floodwater would poison the New Orleans area, carrying as it did a so-called "toxic gumbo" of nasty substances-everything from petroleum to lead to household pesticides. Five years on, there may still be pockets of elevated toxicity (for example, near the sites of oil spills caused by the storm), but as noted in a 2007 paper from the journal Cityscape, "the environmental problems in the city are not significantly different now from environmental conditions before Hurricane Katrina."