Monday, September 26, 2005

Future Public Health Challenges in New Orleans

Public health researchers are always looking for “natural experiments” to study how environmental quality impacts health. Researchers examined how much hospitalization rates fell by in the vicinity of a dirty steel plant when its unionized workers went on strike. Other researchers tested for how much did air pollution decline when the 1996 Atlanta Olympics started. This event led to a sharp decrease in driving and activity in this city and researchers tested for how much did smog related hospitalizations decline by.

Does New Orleans offer such a “natural experiment”? Will we learn new facts about how “sludge” and dust exposure affect human health? There would seem to be a huge self selection issue of who returns to this city to be “treated”.

Here are the facts about pollution exposure now.

1. The most immediate threat is bacteria which exceed health standards by a factor of 10.
2. Katrina flooded 25 major and 32 minor sewage-treatment facilities, releasing hundreds of millions of gallons of sewage into the city. Decaying animal and human remains also are contributing bacteria.
3. Health officials recommend that everyone in the city wear a respirator mask. As the city dries out, dust will be a problem. Breathing dust under any circumstances is unhealthy, but the dust in New Orleans may contain contaminants. Oil products are the most prevalent contaminant in the water and sludge, coming from refineries along with submerged cars and gas stations.
4. Testing also has found slightly elevated levels of lead, arsenic and other metals, as well as pesticides and herbicides. These come from flood runoff as well as household and industrial sources.
5. Cleanup efforts will have to reach the lowest layers of sediment and debris before long-term health threats can be determined, a process that will take weeks.
6. As untreated floodwater is pumped into Lake Pontchartrain, the lake has taken on a distinct septic smell, Mann said. Like the floodwater and sludge in New Orleans, the lake has lots of bacteria but doesn't have high levels of toxic chemicals.