Toxic chemicals found deep at oil spill site

* Levels of polycyclic aromatic hydrocarbons were high

* Chemicals can kill animals, cause cancer

WASHINGTON, Nov 2 (BestGrowthStock) – Toxic chemicals at levels
high enough to kill sea animals extended deep underwater soon
after the BP (BP.L: ) oil spill, U.S. researchers reported on
Tuesday.

They found evidence of the chemicals as deep as 3,300 feet
(1,000 metres) and as far away as 8 miles (13 km) in May, and
said the spread likely worsened as more oil spilled.

The chemicals, called polycyclic aromatic hydrocarbons or
PAHs, can kill animals right away in high enough concentrations
and can cause cancer over time.

“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 in the journal
Geophysical Research Letters.

The Deepwater Horizon oil drilling rig exploded in April,
killing 11 workers and spilling about 4.9 million barrels or
185 million gallons of crude oil.

Terry Wade of Texas A&M University, Steven Lohrenz of the
University of Southern Mississippi and Stennis Space Center and
colleagues began testing the waters around the spill soon
afterwards.

Environmental experts were most worried about the PAHs
because they are so toxic, but not much was known about how
long they could last in the water or how long it would take
them to dissipate.

The initial tests showed they were at high levels very deep
under the water, the report shows.

“Based on our findings, subsurface exposure to PAH
resulting from the Deepwater Horizon oil release was likely to
be associated with acute toxicity effects in discrete depth
layers between 1,000 and 1,400 metres in the region southwest
of the wellhead site and extending at least as far as 13 km,”
the research team wrote.

PAHs include a group of compounds, and different types were
at different depths, they said.

It is possible they dissipate quickly, but no one has yet
showed this, they added.

“Our findings suggest that toxicity effects of the
subsurface PAH compounds could have extended at least as far as
13 km from the wellhead site,” the researchers said.

In September a team at Oregon State University said they
found alarming levels of PAHs in the region, 40 times higher
than before the area was affected by the oil spill.
[ID:nN30228732]

Last week, the Food and Drug Administration and National
Oceanic and Atmospheric Administration said testing had helped
confirm that chemicals used to disperse oil from the BP spill
have not made their way into fish, crabs, shrimp or oysters
from the Gulf of Mexico. [ID:nN29162189]
(Reporting by Maggie Fox; Editing by Jerry Norton)

Toxic chemicals found deep at oil spill site