"Following criticism and questions about its illness data, Deepwater Horizon Unified Command — a response center involving BP, Transocean, Halliburton, the Coast Guard and multiple federal agencies — appears to have tweaked its recording of worker illnesses in the Gulf.
In doing so, its illness statistics have more than tripled from the previous report, which was released by BP two weeks ago. According to new data, spanning April 22 to June 17, 307 Gulf cleanup workers reported illness, and most received first aid and no medical treatment. There have been 424 reports of injuries.
BP and Unified Command's previous accounting of illnesses, from April 22 to June 10, only recorded 86 illnesses."
Marian Wang reports for ProPublica June 23, 2010. 
"Oil-Spill Health Risks Under Scrutiny" (Nature News)
"MMS Moving to Mandate Safety Standards for Rig Workers" (Greenwire)