Using an ivy plant as a natural air filter

HEPA filters (high-efficiency particulate air) are a popular choice for those looking to rid the air at home of harmful particles such as pollen, pet dander, dust mites and tobacco smoke.

But some hazardous particles are simply too small to be trapped in these filters. Tiny molecules like chloroform (in chlorinated water) or benzene (a component of gasoline emitted from boiling a pot on the stove or in car lawn mowers sitting in attached garages).

Extended exposure to both of these chemicals has been linked to cancer.

But researchers at the University of Washington have been able to genetically modify pothos ivy, a common houseplant, to remove both chloroform and benzene from the air around it.

“People haven’t really been talking about these hazardous organic compounds in homes, and I think that’s because we couldn’t do anything about them,” said senior author Stuart Strand, who is a research professor in the UW’s Civil and Environmental Engineering Department. “Now we’ve engineered houseplants to remove these pollutants for us.”

The modified ivy plants are able to express a protein known as 2E1, which transforms the toxic compounds (chloroform and benzene) into molecules the plant can actually use to support their own growth and development.

“This whole process took more than two years,” said lead author Long Zhang, who is a research scientist in the UW’s Civil and Environmental Engineering Department. “That is a long time, compared to other lab plants, which might only take a few months. But we wanted to do this in pothos because it’s a robust houseplant that grows well under all sort of conditions.”

Real-world results are promising for the pothos ivy modified plant.

The concentration of chloroform dropped by 82 percent after three days and was barely detectable by day six. For benzene, the process worked a little slower – by day eight the concentration of benzene dropped by about 75 percent.

The modified plants still need approval from government agencies for production, but the team is busy at work trying to create a protein in the plant to help break down formaldehyde (commonly found in engineered woods and glues) as well.