Last summer I wrote about a review of the health impacts of oil spills (Aguilera et al., 2010) and attempted to extrapolate the results of that review to the 2010 BP oil spill. I concluded at the time that, while physical health impacts were likely limited to those involved in oil cleanup (or consuming contaminated food), past experience showed that psychological impacts on affected communities were common.
Now a new study (Grattan et al., 2011) has looked at just that. Specifically, the authors looked at two Gulf fishing communities. The first was Franklin County, Florida, which was not directly impacted by the spill (i.e. oil did not reach the beaches in the county), but experienced economic effects due to impacts on fishing and tourism. The second was Baldwin County, Alabama, which was directly impacted. The study looked primarily at adults in the fishing/seafood and tourism industries and their families, recreational fishers, and retirees. Study participants were also grouped into those who had experienced economic loss due to the spill and those who had not.
The researchers conducted a series of neurophysiological tests to evaluate psychomotor speed, dexterity, attention, clerical speed and accuracy, response inhibition, divided attention and mental flexibility. They conducted tests for psychological distress, coping strategies, and ability to bounce back from adversity (resilience), and asked questions about the subjects’ perception of risk.
No major differences were found on the neurophysiological tests. Perhaps surprisingly, there were no differences between the directly and indirectly affected communities for psychological distress; however, when instead the authors looked at those whose income was affected vs. not affected, the group with affected income showed higher tension/anxiety, depression, anger, fatigue, confusion and total mood disturbance on the pscyhological distress tests. 35% of participants from Baldwin County and 50% of participants from Franklin county had test scores suggesting possible clinically significant depression, compared to reported historical rates of 9.8% for Florida and13% for Alabama.
For coping strategies and resilience, again the differences were between those whose income was affected or not, instead of whether the community was directly impacted or not. Participants with affected income were more likely to use “behavioural disengagement” to cope (basically giving up on dealing with the problem), and showed less resilience.
Perceived risk differed between the communities. Those in Franklin County were more likely to believe that BP would successfully clean up the spill and that health effects would be limited to short-term effects.
There were some limitations to the study, including relatively small sample size and some differences in characteristics of the different populations studied (age, number of men vs. women, and education). However, since the higher levels of psychological distress are consistent with what we’d expect to see based on previous studies, they probably reflect a true effect.
The lack of significant differences between the two communities suggests that the psychological effects are not a result of direct effects of the oil spill, but rather due to increased economic hardship and other indirect effects on people’s lives. While as a toxicologist I am used to dealing with direct effects on exposed people, I don’t find it surprising that there are psychological effects on people who were not directly exposed but whose lives were affected. I do find it a bit surprising that the effects weren’t stronger on people in the directly affected community; I would have thought that the increased perceived risk might have some psychological effect, but perhaps any such effects were much smaller and masked by the study limitations (and psychology is not really one of my areas of expertise).
There are other studies ongoing related to health and environmental impacts of the spill; it will be interesting to see the results and whether my earlier predictions about health effects probably being limited to those involved in spill cleanup will be supported.
Aguilera, F., Méndez, J., Pásaro, E., & Laffon, B. (2010). Review on the effects of exposure to spilled oils on human health Journal of Applied Toxicology DOI: 10.1002/jat.1521
Grattan, L., Roberts, S., Mahan, W., McLaughlin, P., Otwell, W., & Morris, J. (2011). The Early Psychological Impacts of the Deepwater Horizon Oil Spill on Florida and Alabama Communities Environmental Health Perspectives DOI: 10.1289/ehp.1002915