Empire of dust: what the tiniest specks reveal about the world
For two centuries, London’s buildings were black. Blanketed in sulphurous soot from coal fires – the famous London “pea souper” fogs – a thin layer of carbon coated every surface in the city. London was so dirty that there was no memory that it might ever have been any other way. During the restoration of 10 Downing Street in 1954, it was discovered that the familiar dark facade was not actually black at all, but originally yellow brick. The shock was considered too much for the country to take and the newly clean building was painted black to maintain its previous, familiar appearance.
But then, in the late 1980s and early 1990s, there was a great clean-up. For more than a decade, scaffolding surrounded landmarks like St Paul’s Cathedral, as power washers hosed the grime down into the sewers and out of sight. These days the city is russet and pale grey, silver-mirrored and blue green – the colours of brick, limestone and glass. The pollution is now polychrome: the primary residue adhering to buildings is not the black of carbon soot, but a warmer browny-yellow colour from the organic hydrocarbons in petrol and diesel fuel. As sulphate emissions from traffic fall, buildings may yet turn green as mosses and lichens grow back.
Yet you cannot just blast dust and grime off all of London’s landmarks. Westminster Hall is the oldest building in parliament, built about 900 years ago by William Rufus, son of the Norman conqueror. In 2007, architectural conservators found that its walls were being corroded by air pollution and penetrated by moisture. They reckoned it had not been cleaned in 200 years. It was time.
But how to do this while maintaining respect for the building’s fabric? Limestone is porous, soluble stuff, which could dissolve under strain from high-pressure washing. Fortunately, more subtle methods are available. Delicate carving can be cleaned using poulticing, akin to a clay face mask for the stone, which draws out deep-seated salts and staining. Latex films are another option: they are brushed or sprayed on, then left to absorb grime from the stone, before being peeled off, taking the dirt with them.
News of the epic cleaning project at Westminster reached an artist in New York, who got permission to preserve the latex sheets used to clean the stonework. The artist, Jorge OteroPailos, subsequently displayed them in an exhibition called The Ethics of Dust. In June 2016, I walked into Westminster Hall and confronted a translucent, glowing curtain, 50 metres long and five metres tall, hung from the ancient hammerbeam roof, a patchwork skin encrusted in the grime of the entire city.
Since modernity began, people have complained about airborne dust – but the measures required to control it have come decades or centuries after, if at all. The coalmines and factories that powered Britain’s Industrial Revolution made a capitalist class very rich, while the cost was borne by their workers in their bodies, lungs and blood. The Ethics of Dust was, for me, about human presence made present – about the building rewritten as not only limestone and glass and a woodbeamed roof, or as big abstract nouns like history and tradition and power, but the material traces of millions of bodies, their labours and their livelihoods. It brings the polis, the people, right into the heart of parliament – and it brings a reckoning with the source of Britain’s historical prosperity, too.
Nobody normally thinks about dust, what it might be doing or where it should go: it is so tiny, so totally, absolutely, mundane, that it slips beneath the limits of vision. But if we pay attention, we can see the world within it.
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Before we go any further, I should define my terms. What do I mean by dust? I want to say everything: almost everything can become dust, given time. The orange haze in the sky over Europe in the spring, the pale fur that accumulates on my writing desk and the black grime I wipe from my face in the evening after a day traversing the city. Dust gains its identity not from a singular material origin, but instead through its form (tiny solid particles), its mode of transport (airborne) and, perhaps, a certain loss of context, an inherent formlessness. If we knew precisely what it was made of, we might not call it dust, but instead dander or cement or pollen. “Tiny flying particles,” though, might suffice as a practical starting definition.
In 2015, I found myself driving into a forest fire in the Sierra national park in California. Smoke hung heavy in the sky: the fire behind the hills was one ridge away. The particles in the smoke cloud were the soot and wood ash from a burning pine forest. Today, 8.5m tonnes of this burnt “black carbon” are emitted around the world each year, most not of natural origin, but instead from diesel engines, woodfuelled cooking stoves and burning to clear land for agriculture. Black carbon is a powerful “climate forcer”, absorbing warmth from the sun and contributing substantially to global heating. It is also a major component of fine particle air pollution, known as PM2.5s (particles under 2.5 micrometres in size).
These tiny particles are easily inhaled deep into the lungs. Their evensmaller cousins, ultrafine PM0.1s, can pass through the air sacs in the lungs into the bloodstream, where they can be transported to every organ and can harm potentially every cell in the human body. Particulate air pollution causes not just respiratory illnesses but heart disease, cancers, infertility, even neurodegenerative diseases such as Alzheimer’s. Altogether, it’s the fifth biggest cause of death in the world, accounting for 4.2m lives lost each year. If London’s air was compliant with World Health Organization (WHO) standards for PM2.5s, its residents would gain on average an extra 2.5 months of life.
In Lewisham, south-east London, a young girl named Ella Kissi-Debrah lived with her mother, Rosamund, just 25 metres from the city’s busy south circular road. In 2010, aged seven, Ella started to develop a strange and persistent cough. In February 2013, the nineyear-old died of respiratory failure. For years, Rosamund fought to expose the real cause of her daughter’s death. Finally, in December 2020, Ella made legal history as the first person in the UK to have air pollution listed as a cause of death. In his remarks, coroner Phillip Barlow said there is “no safe level of particulate matter” in the air and called for national pollution limits to be reduced.
Urban dust is much more than