When British Petroleum’s Deep Water Horizon oil well blew out in April 2010, many of us saw pictures of crude oil pouring into the sea. Much of that oil never made it to the ocean’s surface, where it might have been skimmed or burned off. Instead, it was dispersed using chemicals that were poorly tested for their effect on marine life. It seems we must live and learn.
A large amount of the crude oil remained in the water column. Now, new studies reported by Dr. Barbara Block of Stanford University, find significant direct effects of crude oil on the cardiac function of fish. Block and her coworkers found that the polycyclic aromatic hydrocarbons or PAHs found in crude oil, even at low levels, caused arrhythmia in young fish. PAHs interfere with channels that transfer potassium and calcium ions in heart muscles, which are essential to the electrical impulses that keep a heart beating.
The PAHs that are found in crude oil can persist in the environment for years. And some 4,000,000 barrels of crude oil leaked from the Deep Water Horizon well into the Gulf of Mexico. Adding to the problem – the April 2010 spill coincided with the peak breeding season for blue fin and other species of tuna, some of which are endangered in the world’s oceans.
Exposure to polycyclic aromatic hydrocarbons will certainly not help the tuna’s recovery. But we should also be alert to the growing presence of PAHs in our environment, where they may affect our own heart functions as well.
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Please see: Brette et al. 2014. Crude oil impairs cardiac excitation-contraction coupling in fish. Science 343: 772-776
Photo, taken on June 16, 2010, courtesy of Kris Krug via Flickr.
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