Rat-sized snails monitor pollution at a St. Petersburg wastewater plant in a strangely ordinary way: by breathing in incinerator emissions. Though it’s a weird sight, heart monitors fitted to six African snails take readings from three snails breathing clean air and three snails breathing incinerator smoke. When compared, the readings provide information about the health of the snails: Since all other environmental factors are constant, negative findings can be attributed to polluted emissions.
The unconventional but very inventive monster mollusk monitoring method has come under criticism from some environmentalists who claim it is just a publicity stunt. Vodokanal, the company that owns the plant, disagrees. It says the snails monitor pollution better than air-sampling instruments because living, air-breathing organisms are more reliable indicators of risks to humans than mechanical devices.