Toxic chemicals that can kill sea life were present deep under water soon after the Deepwater Horizon rig exploded and almost 185,000 gallons of oil were leaked into the Gulf of Mexico, according to new research published in the journal Geophysical Research Letters.

Polycyclic aromatic hydrocarbons, or PAHs, can kill animals in high enough concentrations and can cause cancer over time. PAHs were found as deep as 3,300 feet and as far away from the leaking well as 8 miles in May, according to the study led by Terry Wade of Texas A&M University and Steven Lohrenz of the University of Southern Mississippi and Stennis Space Center.

"From the time that these observations were made, there was an extensive release of additional oil and dispersants at the site. Therefore, the effects on the deep sea ecosystem may be considerably more severe than supported by the observations reported here," the researchers wrote.

It it unknown how quickly the toxic chemicals dissipate. A research team from Oregon State University reported finding PAHs in the region 40 times higher than before the spill in September (Reuters/MSNBC, Nov. 2). -- LP