We know that air pollution surrounds city-dwellers, but what difference would it make if we could actually see it?
By combining ‘digital light painting’ with air pollution sensors, researchers and artists have found a way to make the invisible visible.
Their photos highlight the health risks of particulate-crowded skies in Wales, India and Ethiopia.
“Air pollution is the leading global environmental risk factor,” says Professor Francis Pope, an environmental scientist at the UK’s University of Birmingham, who led the project with artist Robin Price.
“By painting with light to create impactful images, we provide people with an easy-to-understand way of comparing air pollution in different contexts.”
How can you photograph air pollution?
Particulate matter (PM) is the deadliest form of air pollution for humans. Its key components are sulfates, nitrates, ammonia, sodium chloride, black carbon, mineral dust and water.
To capture the tiny particles on film, the team got low-cost air pollution sensors to measure PM mass concentrations. They then used the sensors’ real time signal to control a moving LED array programmed to flash more rapidly as PM concentration increased.
A long exposure photograph is taken with the artist moving the LED array in front of the camera - the flash becoming a dot on the photograph.
The artist is not seen in the photo because they are moving, but light flashes from LEDs are seen because they are bright. The more light dots appear in the photographs, the higher the PM concentration.
What did the air pollution photos reveal?
The researchers’ findings show air pollution varying dramatically between different locations.
In Ethiopia, concentrations of PM2.5 (fine particulate matter) were up to 20 times greater in a kitchen using biomass stoves than they were nearby outdoors.
In India, two children’s playgrounds just 500 kilometres apart were given the digital light painting treatment. The one in urban Delhi has PM2.5 values at least 12.5 times higher than those measured in a play area in rural Palampur.
Large variations in air pollution were also captured around the Port Talbot steelworks in Wales. Here, air quality monitoring and light painting at dusk in summer measured PM2.5 concentrations in the range of 30-40 mg/m3, when the hourly average value was 24 mg/m3.
“By providing a visual understanding of air pollution that is accessible to people who don’t necessarily have a scientific background, the light painting approach can demonstrate that managing air pollution levels can have a significant impact on people’s day-to-day lives,” says photographer Price.
How dangerous is air pollution?
Air pollution is considered one of the main threats to both environment and human health and a leading cause of death globally.
Particulate matter has multiple impacts upon physical health and is responsible for diseases including heart disease, stroke, and cancers.
The World Health Organization (WHO) estimates 99 per cent of the global population breathe polluted air, causing approximately seven million premature deaths worldwide each year.
The situation is particularly challenging in Asia, where air pollution remains a major problem in countries like India and China, despite several air quality policies and actions.
African countries have also experienced significant deterioration in air quality over the last five decades.
To raise awareness about this deadly issue, the ‘Air of the Anthropocene’ photo project has been exhibited at gallery shows in Los Angeles, Belfast and Birmingham.
