Lisa Song of InsideClimate News has a great piece today exploring the complicated question of the long-term health impacts of oil spills. The short answer is that we really don't know. There are no clear federal guidelines on what to do when a spill happens in a populated area and it's often left up to local officials to make decisions, with results varying from place to place. Song notes the differences in response to three oil spills in U.S. neighborhoods since 2010, including the Pegasus pipeline in Mayflower.
In Mayflower, Ark. authorities quickly evacuated 22 families after a broken pipeline leaked about 200,000 gallons of heavy crude on March 29, 2013. But people living in the same subdivision, just a few blocks away, were not asked to leave. Neither were the residents of the lakeside community where the oil eventually pooled and where the cleanup continues today.
After each of these spills, people complained of headaches, nausea and respiratory problems—short-term symptoms that health experts say are common after any chemical spill and usually disappear as the air clears.
What health experts don't know, however, is whether the fumes could also trigger long-term health problems that become evident only years or decades later. That gap will be increasingly important, because over the next few years the industry plans to build or expand more than 10,000 miles of oil pipelines—including the Keystone XL.
Despite all the new building, Song notes that "there are no plans to conduct long-term health studies in Mayflower, Marshall or Salt Lake City. There also doesn't appear to be any momentum to set federal guidelines for chemical exposures at oil spills, so health officials will be better equipped for future emergencies."
The article takes a close look at the policy response to the Mayflower spill from state health officials:
In Arkansas, health officials decided that Mayflower residents could return to their subdivision when benzene levels in and around their homes dropped to below 50 ppb. (Most of the 22 evacuated homes have been cleared for re-entry, although none of the families have returned.) But people nearby complained of headaches, nausea and other health problems even after officials announced online that contaminants in the air were "below levels likely to cause health effects for the general population." ...
After oil spills, public health decisions usually fall to county or state officials. In Mayflower, those decisions were made by the Arkansas Department of Health (ADH), which set a benzene threshold of 50 ppb.
Lori Simmons, who heads the agency's environmental epidemiology section, said the ADH calculated that a member of the general public could be exposed to air with up to 50 ppb of benzene for up to six months without long-term health effects.
InsideClimate News tried to compare that 50 ppb guideline with guidelines established by other agencies, but found that it was virtually impossible to make a direct comparison. Some guidelines were designed to protect people from certain health effects but not others. Many, like the ATSDR guidelines, come with disclaimers saying they aren't supposed to be used to define what's safe and not safe.
Song notes that "Arkansas' benzene threshold is also considerably higher than the guidelines used in Alberta, Canada, where the heavy crude oil that spilled in Arkansas and Michigan was extracted."
Read the whole thing.