The power of power

Those of you living in the mid-Atlantic region are probably not reading this right now because you don’t have power. I’ve been out of power in my house since last Friday and projections are it won’t come back until the end of the week. I am lucky because my family and I have some backup options, but not everyone has those options.

So that leads me to this question—do power outages affect health? There have been a number of papers examining this question, mostly looking at one-off episodes, as you might expect. One paper, written by Brooke Anderson (postdoctoral fellow here) and Michelle Bell at Yale University examined the effect of the massive 2003 power outage in New York City on all-cause mortality. This was the first city-wide blackout since 1977 and the data from the time period are striking.

A key point with this paper is that often mortality is under-estimated in these kinds of situations because deaths are only counted if they are identified as “disaster-related” (there may be other reasons, but I won’t get into that here). The NYC Department of Health and Mental Hygiene reported the total number of deaths to be 6 over the 2-day period of the blackout, mostly from carbon monoxide poisoning. However, the paper estimated a 28% increase in all-cause mortality which, in New York, translates to an excess mortality from of 90 deaths, an order of magnitude higher than official results.

The power outage in the mid-Atlantic is ongoing but things appear to be improving by the day. According to BGE, the primary electricity provider in Baltimore City, over half of its customers in the city were without power. On top of that the region is in the middle of a heat wave that has been going on for roughly the same amount of time as the power outage. If you figure the worst of it was in the first 3 days, and if New York’s relative risk could be applied here in Baltimore (a BIG if), then given a typical daily mortality of 17 deaths in the summer months, we would expect an excess mortality for the 3-day period of about 14 deaths from all causes.

Unfortunately, it seems power outages are likely to become more frequent because of increasing stress on an aging power grids and climate change causing more extreme weather (this outage was caused by a severe thunderstorm). It seems to me that the contribution of such infrastructure failures to health problems will be an interesting problem to study for the future.