The St. Petersburg waterworks is putting six giant gastropods to work monitoring emissions from a sewage incinerator. The African snails, the size of some rats, are attached to sensors that will show them getting sick if they take in too much bad air.
Some environmentalists say the unusual move is just a publicity stunt aimed at distracting attention from unsafe practices at the incinerator. But the waterworks company, Vodokanal, says it's a serious attempt to improve control over what comes out of the smokestack.
The plant uses conventional gauges to check emissions, but company officials said they also wanted to keep an eye on compounds that might be produced in concentrations too low for the gauges to detect or that might harm humans when combined with other substances.
"Live organisms won't deceive anyone about the danger of pollution," said Olga Rublevskaya, director of wastewater disposal at Vodokanal. The company is also using crayfish to monitor the quality of city water.
"This is very strict control for us. Now we are under the watch of snails and crayfish all the time!" she said.
The snails, which grow up to 20 centimeters (eight inches) long, live in a fish tank inside the city's Southwest Waste Water Treatment Plant. They are attached to sensors that measure their heartbeat and some other vital signs. Three breathe clean air, the other three diluted air coming from the plant's chimney.
If sensors register an unfavorable change in the latter group's behavior and condition, it would be an immediate signal that air coming from the burnt sewage residue was dangerous.
"The African snails, which are able to live for up to seven years, will also help to test the influence of possible accumulating substances over a long period," said Sergei Kholodkevich, an ecological researcher who came up with the idea for using the snails.
Kholodkevich, who works at an institute of the Russian Academy of Sciences, said he chose snails because they had lungs and breath air "like people do."
"Their other advantage is a settled way of life, compared to mice that run all the time. The third is that they have shells where sensors can be affixed, and no limbs to scratch themselves and kick off the sensors," he said.
Steinar Sanni, a biologist from Norway's International Research Institute of Stavanger who has studied the program but is not connected to it, said snails and other animals can be very effective for monitoring industrial emissions and water quality.
"We'll definitely see more such ecological solutions in the world in future," he predicted.
Local environmentalists, however, are skeptical and say the waterworks is trying to fend off criticism of the sewage treatment plant, which they say is burning toxic industrial waste.
Dmitry Artamonov, who heads Greenpeace's St. Petersburg office, accused Vodokanal of hiding information about the plant's effects on the environment. He said Greenpeace was denied permission to inspect the city's treatment facilities.
"And we understand the reasons for that. The issue is that the local treatment facilities are meant for treatment of domestic waste but not for treatment of industrial waste that contains toxic substances and also gets dumped into the sewage waters," Artamonov said.
Civilized countries, he said, no longer burn such residue, and the city government should require local industries to introduce new clean technologies and forbid them from dumping polluted waste into sewage waters.
"As for snails, it can be hard for them to indicate the environmental danger immediately, because such substances as dioxins, for instance, can accumulate in an organism over a long period of time and only decades later provoke cancer," Artamonov said.