Steven Johnson's book The Ghost Map is an account of the horrific cholera outbreaks in London in the 1850s. Doctor John Snow and Reverend Henry Whitehead disagreed with the official line that the disease that was killing so many people was airborne. Snow suspected that cholera traveled between people and meticulously mapped the number of deaths per household in Soho. Meanwhile, Reverend Whitehead noticed patterns of behaviour in the sick people he visited. The Soho epidemic appeared to centre on a communal water pump in Broadwick Street and Snow eventually convinced authorities to remove its handle.
Tragically, cholera is still prevalent in many areas of the world. Having read Johnson's graphic descriptions of what the disease does to a human body, and knowing that it can be prevented, water sanitation projects always get my attention. Also, I spend much of my professional life talking about toilets, so when Toilet Twinning came to my attention on Twitter I felt I should support it and twinned my loo with one in Liberia.
The Ghost Map by Steven Johnson is available is available to buy at Foyles.