Lingering Harm:
Oil's Toxic Legacy
By Riki Ott

Over 30 million gallons of crude oil blackened the waters of Prince William Sound in the Exxon Valdez spill of 1989. At the time, the general consensus among scientists was that the oil spill’s effects on sea life would be deadly but short-term. They predicted that birds and marine mammals would suffer and die through hypothermia, drowning and ingestion through preening and grooming. Fish and other marine life in the water column would take a hit from toxic compounds that would remain at concentrations in mere parts per million parts of seawater — seemingly very low levels. But scientists believed that oil stranded on beaches and in sediments would rapidly degrade, leaving an asphalt-like substrate that was ‘environmentally benign’ or harmless. Wildlife would recover rapidly.

They were partially right. The Exxon Valdez killed more wildlife than any other oil spill in history. But the killing did not stop in 1989 and, nearly two decades later, the Prince William Sound is still struggling to recover. Ultimately, the Exxon Valdez unleashed a cascade of events that would change scientists’ understanding of oil toxicity. Today scientists know oil is a thousand times more toxic than ever thought before.

As early as 1990, Exxon scientists heralded the ‘remarkable recovery’ of the sound. But government and other scientists continued to observe impacts. Pink salmon eggs, developing in oiled beaches, died in ever increasing numbers from 1990 through 1992. Young sea otter pups, first weaned from their mothers, died by the score on oiled beaches. Harlequin ducks died over winter on beaches covered in black.

This was only the beginning. In April 1993 the Pacific herring stocks crashed unexpectedly, followed by the collapse of pink salmon stocks in August for the second consecutive year. Frustrated fishermen blockaded Valdez Narrows and held up oil tanker traffic for three days to bring public attention to the ailing sound. Fishermen reasoned that the fish population collapses stemmed from delayed effects on fish exposed to deadly oil when they were eggs, embryos, larvae and juveniles. It took scientists another seven years to prove fishermen were right and to recalibrate the bar on oil toxicity.

Finally, in response to mounting public pressure, scientists conducted four ecosystem studies on Prince William Sound. Two studies focused on PAHs, or polycyclic aromatic hydrocarbons. These are benzene compounds found in the supposedly environmentally benign oil. PAHs are slow-acting poisons that kill sensitive eggs and embryos, stunt growth, jam reproductive codes of juveniles and sicken adults. Today, beaches in the sound are still covered in PAHs.

These two studies, in addition to a growing body of medical studies in the 1980s and 1990s led scientists to the conclusion that PAHs had a persistent deadly effect on humans. By 1999 scientists had established the severe long-term toxicity of oil at extraordinarily low levels — 1,000 times lower than levels previously thought safe. Medical doctors linked low levels of PAHs with respiratory problems, like asthma and bronchitis, cancer and other alterations in the DNA code, and the aggravation of heart attacks and arrhythmias.

With this evidence, U.S. EPA added 22 PAHs to its list of persistent, bioaccumulative and toxic pollutants in 1999. This deadly list also includes mercury, dioxin and lead. With the exception of PAHs, chemicals on this list are highly controlled substances with production of some, like DDT and PCBs, banned in the U.S. and elsewhere.

Like an incoming tide, PAH levels in air and water now pose a serious threat to public health and the environment. According to the National Research Council, the average PAH level in some rivers in North America approaches the range known to sicken and kill wildlife and diminish entire populations of species.

But federal laws and regulations have not kept up with the new science on oil toxicity and do not adequately protect the public and the environment. We need to treat oil as what it is, a deadly pollutant that is, quite literally, harming people, our children and all other species.

Routine Exposure
Findings of OIL: A Life Cycle Analysis of its Health and Environmental Impacts a study by the Center for Health and the Global Environment, Harvard Medical School:
• Occupationally-related fatalities among workers in the oil and gas
extraction process are higher than deaths for workers from all other U.S. industries combined.
• Many leaks and spills occur in developing nations where safety regulations for pipelines and oil rigs are inadequately enforced.
• Gasoline and many of its additives can lead to acute and chronic toxicity, and is associated with some types of cancer.
• Groups at high risk for exposure to gasoline and its additives include: employees in the distribution, storage and pumping of gasoline; people living near refineries, transfer and storage facilities and service stations; automobile drivers who pump their own gas; people who live in houses with attached garages; and those whose drinking water has been contaminated with gasoline.