It takes hardship, observation, data, and in the case of London’s 1858 cholera epidemic – a stench from the River Thames so foul that Parliament ceased functioning. The next order of business was for the members of Parliament to quickly enact legislation ordering the overhaul of London’s sewerage system. The cholera pandemic lasted internationally from 1846 to 1860.

It had taken some time to get to that point. In 1836 the General Register office had been established to collect data on births, marriages and deaths. Its annual report to parliament was drawn up by William Farr, a statistician who had studied at the Paris Medical school. Farr was particularly interested in how death rates varied according to the presence of disease. He produced the English Life Tables, which showed localities where mortality and disease were correlated, and where the causes were preventable. These were the beginnings of the science of epidemiology.

Cholera struck without regard to social status, region or livelihood. Farr noticed on investigating further that there was a relationship between height above the river level at which one lived, and the rate at which victims succumbed to cholera. The higher above, the lower the chance of mortality. Farr believed that the vapors emanating from the Thames were the culprit.

However, it was not until 1855 that Dr. John Snow established a positive link between water and the disease. Although there were regulations against water supply companies taking their commodity from the most polluted section of the Thames, one company was delinquent. Their clients were dying at a rate ten times more than those whose water came from uncontaminated sources.

It took three more years before Parliament acted to rebuild London’s sewage system to carry the waste out to sea. Farr was indeed right – the stench had something to do with it.

Over the next fifty years Louis Pasteur established that infectious germs can be air-borne, and Robert Koch and others began identifying micro-organisms that caused diseases such as TB, cholera, diphtheria, typhoid.

The case of cholera in London illustrates how empirical data can be less persuasive than the senses. It also shows how governing bodies can fail to enact remedies until their members are personally affected.

However much we are told that every little step helps in slowing environmental violation, it is unlikely that large steps will come from anyone other than those in power, after they have personally suffered the effects. Such is the nature of a progress trap.

Burke, J. The Day the Universe Changed, BBC, London, 1985