Quirks & Quarks

A genetically modified houseplant could suck up dangerous indoor air pollution

The modified plant can absorb and break down benzene and chloroform

The modified plant can absorb and break down benzene and chloroform

Scientists at the University of Washington have genetically modified a common houseplant, the pothos ivy otherwise known as "Devil's Ivy," to suck up cancer causing chemicals from your home. (SandeepHanda / Pixabay)

We have some good and bad news about the air in your home. The bad news is that it's polluted with gaseous carcinogenic chemicals. But the good news is that scientists have genetically modified a common houseplant that can suck up some of those indoor air pollutants.

Dr. Stuart Strand, the senior author on the study and research professor emeritus in the department of civil and environmental engineering at the University of Washington, said the reason they chose the houseplant Pothos ivy — otherwise known as Devil's ivy — is because scientists had already shown it can be transformed through genetic manipulation.

"We don't see much degradation of benzene by our wild type pothos, our untransformed pothos," said Strand. "Whereas our transformed pothos is able to remove all of the benzene within a week from very small plants in small vials. The same applied the chloroform except the reaction rate was even faster."

Benzene, which comes from second hand smoke, candles, and fuel that's stored in houses or garages, is a known carcinogen. And chloroform, which comes from household water when the the chlorine in the water reacts with traces of organic matter, is a probable human carcinogen.

Both are gases that cannot be filtered out by household air filters which target particulates.

"We're concerned about cancer here," said Strand. "The levels of benzene and chloroform (...) can approach those that are regulated for industrial settings. And this is alarming because, after all, our most vulnerable people — our little children and infants — they're exposed to the home air all day long. And we want to limit their exposure the most. So even trace amounts of these compounds that cause cancer are of concern."

The gene that went into the plant

Strand and his team decided to use the gene for a protein called cytochrome P450 2E1, or 2E1 for short, which is present in all mammals, including humans.

"We got the idea for using the gene out of the medical literature," said Strand about the 2E1 gene that's been studied for a long time because of how it's involved in cancer initiation. 

Long Zhang, a research scientist in Stuart Strand's UW's civil and environmental engineering department, puts a pothos ivy plant into a glass tube to test its ability to break down benzene or chloroform. (Mark Stone/University of Washington)

"Chemicals like benzene come into the body and this enzyme will transform them to phenol. But when it does that, that's a high energy reaction and it forms radicals that can modify DNA that are nearby. These radicals dissipate within a few seconds, but that damage can be done if this reaction occurs within your body."

By taking this gene out of the body and putting it into a common houseplant that's easy to care for, the plants can degrade these chemicals without any harm to humans.

The way it'd work in your home

Strand has yet to test his plants with more realistic concentrations of benzene and chloroform. He said they plan on testing them in "bio-reactors — flow through systems where we can get the concentrations down to realistic levels and make sure everything works as we expect it will."

For plants in the home to be able to effectively remove hazardous molecules from the air, they would also need to be inside an enclosure with something to move air past their leaves, like a fan. (Mark Stone/University of Washington)

The way he envisions this working in a home is to create a mini-greenhouse or small living wall arrangement about the size of a window, in which air would be blown across the plants to remove the pollutants, and then return the air to the room. "So a fan driven mini greenhouse if you will." 

GMO plant could soon be available in Canada

Pothos ivy cannot grow outside in Canada because they're sensitive to frost, so Strand said the Canadian Food Inspection Agency has already approved it for sale in Canada.  He and his team are looking for a commercial partner to sell them to the mass market.

In the United States where this plant can grow in regions that don't get any frost, the pothos ivy doesn't flower, so at least the genetically modified pollen can't spread. To prove that it's safe in regions that don't frost, Strand has to prove that the modified plant won't be more aggressive than the unmodified plant.