Thirty years after Exxon Valdez, the response to oil spills is still all wrong | Riki Ott and Jack Siddoway

Chemicals used to clean up spills have harmed marine wildlife, response workers and coastal residents. The EPA must act

Thirty years ago, on 24 March 1989, communities in Prince William Sound, Alaska, awoke to horrific news: the Exxon Valdez, an oil tanker, had run aground and leaked 11m gallons of oil into the sound. Chaos ensued. Fishermen desperately began collecting oil in five-gallon buckets. Exxon, meanwhile, responded by burning floating oil and dumping toxic oil-based chemicals called "dispersants". Dispersants break oil apart into smaller droplets, and this was assumed to enhance natural dispersion and degradation of oil, thereby "cleaning up" a spill. Instead, the dispersants formed chemically enhanced oil particles that proved to be more toxic to humans and the environment than the oil alone.

Twenty-one years later, on 20 April 2010, the BP Deepwater Horizon drilling rig exploded off the Louisiana coast, releasing 210m gallons of oil into the Gulf of Mexico. The subsequent response was all too familiar - burning oil and dumping dispersants once again. Two million gallons of dispersants were applied to "clean up" the spill. Instead, these chemicals led to unprecedented oil deposition on the ocean floor, resulting in severe impacts to marine wildlife from the sea floor to the upper ocean - including large dolphin die-offs, fish kills, and deformities - and devastating pulmonary, cardiac and central nervous system illnesses for response workers and coastal residents.