Watching Mephitic Air
Watching Mephitic Air is an audio-visual installation visualising and sonifying pollution data from SE1. Five years of data from between 31st August 2016 and 31st August 2011 from the Old Kent Road pollution sensor operated by Kings College is shown at a rate of one day a second. The shape of the stream is dictated by the wind speed and direction. The size of the stream responds to the intensity of the pollutants that day.
The three streams represents Nitric Oxides (NOX), Nitrogen Dioxide (NO2) and PM10s – particles of between 2.5 and 10 microns in size. Most of these pollutants are produced by car exhausts. NOX and NO2 are direct products of internal combustion. NOX is gas at room temperature and is thus represented as light, gaseous bubbles. NO2 is liquid at room temperature, though due to its volatility and the heat of the exhaust, quickly evaporates. This is represented as the bronze liquid it is when it’s stable. PM10s are a by-product of the catalytic converter of most cars which use platinum and palladium.
The sounds move spatially in response to the wind speed and direction shown in the data, with their volume mapped to the amount of pollution measured each day. The choice of sound used for each stream represent our critical interest in the data; one is a field recording made from the roadside sensor that collected the data, another the sound of a catalytic converter sampled through an automotive microphone, and the third a recording of platinum mining in Norilsk, the most polluted city in Russia.
The acid rain which now falls in Norilsk has made the top soil so polluted that it can be mined for previously deep-excavated minerals, including platinum. Meanwhile, the platinum residue produced by the function of the catalytic converters used in Western vehicles is now a common component of PM10, a residue now so widespread that it can be refined from the dust left on busy city streets. At the center is the catalytic converter – built with the platinum commonly mined in Norilsk, and now transferring it as dust onto city streets, its purpose is to reduce engine emission of NO2, NOx, and PM10: the pollutants this dataset measures.
At various points throughout the five years there are significant gaps in the data. These are truthful represented as gaps in the streams. Whether these gaps are due to redaction of data, malfunction or accident is unknown.
Watching Mephitic Air was a collaboration between myself and Tobias Revell for SE1 Data Stories as part of London Design Festival of at the London College of Communication. It was also exhibited at STRP Scene #2 in Eindhoven.