Elizabeth Weise’s USA Today article about potential health effects of the Gulf oil disaster and its cleanup notes that we don’t have a whole lot of research to draw on about this kind of exposure. Residents and cleanup workers alike will be exposed both to the oil itself and to cleanup agents, particularly the chemical dispersants.

Weise references a Korean study conducted following the 2007 sinking of an oil tanker of the Korean coast, which found that residents had an increased risk of headaches, nauseau, and neurological and respiratory symptoms. With regards to the dispersants, she reports, “The potential human hazard for the two dispersants being used to break up the oil is rated high for one of them, moderate for another, according to the Material Data Safety Sheets posted on the government’s Deepwater Horizon Response website.”

But the section of Weise’s article that really caught my attention was this one (emphasis added):

Jeffrey Short, a scientist with the ocean conservation group Oceana, says in previous spills, especially Exxon Valdez, that was a danger during the shoreline cleanup phase.

There isn’t much scientific literature on the topic in part because “the people who got sickest and won against Exxon got settlements that required that the records be sealed. But there were a lot of anecdotal complaints about the impact on cleanup workers,” says Short, who was lead chemist for the National Oceanic and Atmospheric Administration on the damage assessment at the Exxon spill.

When health issues end up in court, it’s not unusual for the case to end in a settlement that requires both sides to keep confidential the documents involved in the case. These documents may contain important health information, though (such as results of clinical studies or surveillance efforts), so public health loses out. This is one of the classic examples of “sequestered science,” or scientific knowledge concealed from the public.

My colleagues at the Project on Scientific Knowledge and Public Policy held a conference on this problem of sequestered science and published several of the papers from the conference in an issue of the Duke University School of Law’s journal Law and Contemporary Problems. Authors of the articles suggested mechanisms for getting sequestered public-health information to the public; their suggestions included publicly available registries study data (which could be anonymized) and instructions to juries to consider previously negotiated confidentiality agreements when deciding punitive damages. Daniel J. Givelber and Anthony Robbins offer this straightforward suggestion:

For judges and courts, the most straightforward response is to refuse to enter protective orders calling for secrecy relating to materials divulged during pretrial discovery or settlement agreements. Thus, someone who breaches a confidentiality agreement would no longer risk being in contempt of court.

The lack of availability of health information on those who sued Exxon for illness following the Valdez spill and cleanup is just the latest example of how sequestering science harms public health.