Yet another reason to wear your favorite jeans
The International Agency for Research on Cancer (IARC) classifies outdoor air pollution as a substance that is known to cause cancer in humans. We all know that pollutants emitted by cars and power plants are bad for us, so what if there were a simple way to reduce the amounts we breathe?
Tony Ryan, a chemist from the University of Sheffield, and Helen Storey, a former fashion designer, have come up with a solution called “Catclo.” The name is short for “Catalytic Clothing,” a concept whereby nanoparticles of titanium dioxide imbedded in jeans can help clean the air.
The idea is fairly simple: titanium dioxide is a photocatalyst. This means that it can make chemical reactions occur when it is exposed to the right wavelength of light — namely ultraviolet light, available from sunlight. It can be washed into fabric during a regular wash cycle by including an additive in the water that will bind to the garment until the fabric starts to degrade, which usually happens after 10–20 washes.
The nanoparticles are 1000 times thinner than a strand of human hair, and because of the extensive surface area of the fibres in the denim, it wouldn’t take many pairs of jeans to make a difference. Ryan suggests that only half the population of Sheffield would need to wash their jeans with the product to bring the British city’s air quality to an acceptable level.
When light shines on a garment embedded with the nanoparticles, it excites the electrons on the surface. They, in turn, react and split surrounding oxygen molecules into two oxygen atoms. The oxygen atoms then react with water molecules in the air, which creates bleach that bleaches nitrogen oxides from the air. Tests have been conducted, and this bleach does not appear to cause any ill effects to people wearing the garments.
This idea isn’t just speculation. Titanium dioxide is already being used for self-cleaning glass and concrete to reduce discoloration caused by air pollution.
Although the IARC has classified titanium dioxide as possibly carcinogenic to humans, this characterization is based on people inhaling titanium dioxide dust — a completely different type of exposure. It is currently used in foods like candy, pastries and soymilk to give them a whiter look. It has been shown to have the potential to damage DNA, but only in quantities far higher than could ever be ingested.
There are more jeans than humans on the planet, so this could be a conceivable way to combat air pollution. Would you be willing to clean the air with your jeans?