Painting with pollutants NOT everything to do with pollution is ugly. This abstract art was created using paints made from the metallic run-off collected from polluted rivers in Ohio. The artwork is a collaboration between environmental engineer Guy Riefler and artist John Sabraw, both of Ohio University in Athens. When water from abandoned coal mines flows into local rivers, it can pollute them with iron, as well as making the water acidic. Once exposed to air at the surface, the iron oxidises to form a disgusting yet colourful orange sludge that kills off much aquatic life. Riefler saw something beautiful in the muck. “I was coming back from rivers with stained socks,” says Riefler. “Most pigments are ironbased anyway, and we thought that we could use this water to create paints.” Collecting underground water before it hits the air allows Riefler to control the rate of oxidation, generating different colours of iron sludge. When dried, these can be ground down and made into oil paints. “Iron is remarkably flexible,” he says. “You can create a range of different colours: yellows, oranges, reds and blacks.” Sabraw has been incorporating the paints into his artwork and advising Riefler on what makes a good pigment. “My job is to be the sensitive one,” he says. “I play with the pigments and their mixing into paints, and discuss their viability with Guy.” Despite their murky past, the pigments are safe to use and produce. Riefler hopes to be able to sell some of the paints commercially and then use the money generated to help restore the very rivers the pigments are derived from. “There aren’t enough resources to clean up the rivers right now,” Riefler says. “We could produce a tonne of pigment per day. If we can generate a strong pigment the paint companies like, we can fund our mission to restore the rivers.” Laurence Pope