Something's in the air

It was common knowledge - the air outside was bad. Rich people would move to the countryside to escape it, because with people dying all around you, it's not necessarily the sort of thing you'd want to be associated with. Keep your windows and doors shut, or run for the hills?

With the Black Death sweeping over Western Europe in the 14th Century, people were dying left, right and centre. The feeling in the air wasn't good - figuratively and literally - morale was low, minorities such as foreigners, beggars and lepers were persecuted, religious fanaticism increased with the Flagellants seeing the Black Death as a punishment from God and thus all must repent. Plus, the miasma was the cause of the disease.

Miasma comes from the Greek word meaning pollution. The ideas that disease was caused by 'something in the air' is known as the miasma theory of disease. An example of this is the disease malaria, which means 'bad air' in Italian (mal aria). Miasma was considered to be a poisonous vapour that travelled through the air. It was composed of particles formed from decomposing matter (miasmata) and was easily identifiable by its foul, disgusting smell. It is easy to see how a link could form here - with dead bodies lining the streets, a bad smell in the air; it wouldn't take a rocket scientist to put two and two together to say that disease is caused by bad smells. Well, rocket scientists weren't exactly a dime-a-dozen in Medieval times so these links continued to proliferate. Plague doctors during this time would carry sweet-smelling plants and herbs in an attempt to ward away the bad air when they went to visit patients.

The concept of miasma came long before the Medieval period, although it was popularised during that era. It was in fact the Ancient Greeks who were the initial proponents of this theory - the father of modern medicine, Hippocrates suggested a link between the environment and illness, noting an association with places that were damp, dank and foul-smelling. Asclepius, the god of medicine, was said to treat 'pestilential air' with 'sweet-smelling airs'. Plato also had his own opinion, saying that bodies in states of putrefaction were sources of this smell, and Roman doctor Galen suggested that inhaling the breath of ill people with bad breath was a dangerous task indeed.

But how do you avoid air, itself ubiquitous in nature and all around us? It is natural to say that bad smells offend - they can even make people ill if they are too strong - but the cause of disease was confounded by the presence of bad smells. In the absence of any other possible reason, miasma was the one that continued. Even in the 19th Century, the prevailing theory was that disease was caused by unpleasant odours.

However, this time, the link was put forward concurrently with bad sanitation. This time, the disease was not that of the Black Death, but cholera. With filth being quite distasteful to the middle and upper classes, people began to equate bad smells as coming from filthy conditions, therefore, disease comes from bad sanitation. Again, it's perfectly possible to see the logic. Even Florence Nightingale campaigned for cleaner hospitals in her Fight against the Filth.

It took a plucky doctor by the name of John Snow to connect cholera and dirty water, and by removing the water pump handle at Broad Street, the deaths from cholera shot down. The Vibrio cholerae bacterium was then discovered in 1854, but it took thirty more years and the rediscovery of the bacterium for the miasma theory of disease to be displaced by a more familiar concept - the germ theory.

So, what is the difference between miasma and germs? Well, the germ theory has a stronger scientific basis behind it, rather than just being 'a bit nasty to the nose', which is what miasma proffered. Viruses and bacteria can indeed be transmitted via the airborne route, but it's not their smell that causes the illness. Hay fever can be exacerbated by pollen in the air, but pollen's not necessarily pongy. Smells can be produced by organisms by their metabolism (just ask a cow), but it is not necessarily the chemicals produced in an odour that causes an illness.

On the other hand, the filthy nature that miasma was so often associated with allowed a different problem to be solved - hospitals became cleaner and more sanitised, so surely a positive can be drawn from it.

Unfortunately, technology and time period were against us this time round, but don't assume that something suspicious in the air is going to put your body into overdrive. Just pull out the scented candles, spray some air freshener and visit your doctor for some advice.