I’ve been asking question about the quality of the air surrounding the oil leak areas...this may help with some answers.
See this....and I don’t think these stats even include the crap in the air from the dispersants.
BP Oil Spill - Toxic Gases Spreading Inland Scientist Says Move Out. (WWL CHANNEL 4 REPORT)
http://www.youtube.com/watch?v=4q-msqPnkD4&feature=related