London’s got a sticky solution for its air pollution problems. For the past few months, the city has been capturing particulate matter and other auto emissions by spaying an adhesive onto the ground in areas with high rates of air pollution.
The idea has been supported by London Mayor Boris Johnson, who calls the calcium-based adhesives “wonderful contraptions.” This article from the BBC explains the process.
Between midnight and 06:00, the roads are first swept and jetwashed by a machine similar to a road dust sweeper.
Then a solution of calcium and water is applied by a modified winter gritting machine with a very fine sprinkler-like system attached. Once it settles it is hardly visible.
The aim is to stick tiny sooty particles called PM10s to the road. PM10 is produced by exhaust fumes as well as tyre and brake wear and can cause asthma, cardiovascular problems, lung cancer and premature death.
Some scientists have scoffed at the idea, not to mention its roughly $1.4 million cost. But according to officials at the city’s transportation agency, Transport for London, the scheme has brought down levels of particulates in the air by 14 percent.
And that’s the crucial element for Johnson and other officials. The city is trying to get into compliance with a set of European Union standards that require cities to have fewer than 35 “bad air” days per year. Those goals must be met by 2012, or the city could face fines of more than $450 million.
The glue approach is just one of many effort TfL says it’s making to bring down levels of particulate matter in the air. And officials note that the scheme is only being used in certain areas with high pollution rates, covering about 19 miles worth of roads. Conveniently (and, critics complain, not coincidentally) the sensor being used to report to city’s pollution levels to the EU is located on one of these streets.
Photo credit: Luke MacGregor / Reuters