Study finds weathered BP oil is much more toxic than when it was fresh

Published: December 5th, 2012 at 4:43 pm ET


Title: Gulf spill harmed small fish, studies indicate
Source: Science News
Author: Janet Raloff
Date: November 19, 2012
Emphasis Added

[…] Among oil constituents that most threaten sea life are polycyclic aromatic hydrocarbons, or PAHs. Through a process known as weathering, lighter-weight chemicals evaporate off of fresh oil, rendering what’s left progressively heavier and sludgy. New chemical analyses show that weathering reduces oil’s propensity to shed PAHs into water, finds Damian Shea of North Carolina State University in Raleigh. The bottom line, he concludes: Weathering reduces oil toxicity.

“But in our hands, weathered oil is more toxic,” said Andrew Esbaugh, a fish physiologist at the University of Texas at Austin’s Marine Science Institute who directly tested the effects of weathered oil on fish. Along with a broad team of researchers from several universities and the National Oceanic and Atmospheric Administration in Seattle, he compared the relative toxicity of weathered oil to fresh BP oil in newly hatched, lab-reared Gulf cobia and mahi mahi.

To simulate how waves disperse oil constituents, his team put oil and seawater into a blender and then spun the mix. They measured the amounts and types of PAHs that entered the water in each batch before exposing hatchlings to the mix for 48 to 96 hours.

Half of the baby fish died after exposure to water containing 5 to 10 micrograms per liter of weathered oil and its PAHs. To achieve the same kill rate with water hosting fresh BP oil, Esbaugh reported, it took concentrations four to eight times higher. […]

Published: December 5th, 2012 at 4:43 pm ET


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4 comments to Study finds weathered BP oil is much more toxic than when it was fresh

  • Isotope Isotope

    Hydrocarbons may be linked to Pancreatic Cancer in humans, so these hydrocarbons in the ocean might be a problem for people swimming, diving, etc. who come in contact with them

  • ftlt

    Has anyone seen the reported health numbers on the Exxon Valdez clean-up workers???… Scary stuff… Wonder about the reports accuracy??… The early death reports were off the charts… How many workers worked on the cleanup on the gulf coast???… Will the numbers from Alaska spill recapitulate themselves with the Gulf's spill clean-up workers life spans???

    The ones who were not allowed safety gear – because it looked bad and set a precedence as a minimum safety standard for those coming into contact with the oil spill materials…

    We live in a world gone mad….

    • amberlight amberlight

      Then there are the numerous illnesses and premature deaths among WTC 9/11 rescue and clean-up workers, who were assured that there were no hazardous materials on site. How can ANYONE believe what government & industry have to say about ANYTHING!?

  • markww markww

    LEGAL MURDER no safety equipment Tony Hayward and others even in the adm are guilty of murder and fake safety and intimidation of the masses