The Ghost Map by Steven Johnson

/ posted in: Reading

“..epidemics create a kind of history from below:  they can be world-changing, but the participants are almost inevitably ordinary folk, following their established routines, not thinking for a second about how their actions will be recorded for posterity.  And of course, if they do recognize that they are living through a historical crisis, it’s often too late – because, like it or not, the primary way that ordinary people create this distinct genre of history is by dying.”  page 32

The Ghost Map is the story of the Broad Street cholera epidemic in 1854.  I knew the basic story.  There is an outbreak of cholera in London.  They trace the source to a well.  They removed the handle from the pump of the well and the outbreak stops.  It is one of the first epidemiological studies done.

I didn’t know the deeper story.  John Snow was a scientist who had been working on proving that cholera was waterborne and not a result of foul air for years and was just waiting for the perfect outbreak to prove his point.  Henry Whitehead was a local pastor who initially didn’t believe the water theory and opposed the removal of the handle from the well known to be the cleanest in the area.  In the aftermath of the epidemic they were on the same committee charged with compiling the data.  Whitehead knew everyone around and was able to hunt down people who had fled the area to see why they had survived.

The book highlights the challenges of epidemiological studies.  People have to remember what common things they did in the last normal days before a disaster.  They found the key was asking the children.  That made me laugh because that is still true.  A lot of times I’ll be asking questions about a sick pet and will ask if he got into anything recently and the adults will say no and the kids will say, “He ate a pack of crayons and the leg off my Barbie.”  Or they know that the cats have been fighting.  They know all the dirt on everyone.

The book also looks at the history of cities as breeding ground for epidemics.  At the time of this cholera outbreak, London was the largest city and experts thought it couldn’t get any bigger without systemic collapse.  Epidemics and city growth were linked.

“The dramatic increase of people available to populate the new urban spaces of the Industrial Age may have had one other cause:  tea. …

… Brewed tea possesses several crucial antibacterial properties that help ward off waterborne diseases:  tannic acid released in the steeping process kills off those bacteria that haven’t already perished during the boiling of the water.  The explosion of tea drinking in the later 1700s was, from the bacteria’s point of view, a microbial holocaust.  Physicians observed a dramatic drop in dysentery and child mortality during the period.  (The antiseptic agents in tea could be passed on to infants through breast milk.) Largely freed from waterborne disease agents, the tea-drinking population began to swell in number, ultimately supplying a larger labor pool to the emerging factory towns, and to the great sprawling monster of London itself.”  pages 94-95

The last part of the book looks at the development of sewer systems that happened afterwards and how that saved London from other outbreaks.  It also looks at modern mapping and how it benefits cities.  The most interesting example was New York City’s 311 system that is designed to give people a place to talk to authorities about non-emergency matters but is also designed to track calls to let officials find out about local concerns.  After a major power outage they got a lot of calls about insulin not being kept cold so information about shelf life of insulin is now part of their emergency briefings.