Study shows just how much toxic air office plants can remove in a single work day

A small green wall containing a range of indoor plants can effectively remove toxic air pollutants from the surrounding air in just eight hours, according to a new study.

The World Health Organisation estimates 6.7 million people die prematurely worldwide due to air pollution.

Since people across the globe spend about 90 per cent of their time indoors, including in offices, homes or schools, experts have called for adopting new strategies to improve indoor air quality.

While previous studies have shown that plants can remove a wide range of indoor air contaminants, the latest, yet-to-be peer reviewed study is the first to show they can clean up petrol vapours – one of the largest sources of toxic compounds in buildings worldwide.

Offices often connect directly to car parks, either by doors or lift wells, making it difficult to avoid harmful petrol-related compounds seeping into work and residential areas.

Studies have shown that many buildings are also exposed to toxic petrol fumes from nearby roads and highways.

“This is the first time plants have been tested for their ability to remove petrol-related compounds, and the results are astounding,” study co-author Fraser Torpy from the University of Technology Sydney (UTS) in Australia said in a statement.

The new research, conducted in partnership with plant scaping solutions company Ambius, found a small green wall containing a mix of indoor plants could effectively remove harmful, cancer-causing pollutants.

Scientists tested the ability of the Ambius plant wall system placed inside chambers with a small volume of petrol vaporised inside, and compared it with the effect observed in chambers with no plants inside.

While a leak in each of the chambers could not be ruled out, researchers expressed confidence that plants still removed over 40 per cent of total volatile organic compounds in the eight-hour test period.

Almost all harmful chemicals such as alkanes, benzene derivatives and cyclopentanes were removed, they noted.

Although previous studies have shown plants can remove toxic chemicals from the air, these have often looked at single chemical species and not at their ability to filter complex mixtures.

Researchers said the green wall by Ambius could remove 97 per cent of the most toxic compounds from the surrounding air in just eight hours.

The green wall included plants such as the Devil’s ivy, Arrowhead plants, as well as Spider plants, and scientists found that over a typical workday, the plants can reduce the levels of some noxious cancer-causing compounds to below 20 per cent of their starting concentrations.

“Not only can plants remove the majority of pollutants from the air in a matter of hours, they remove the most harmful petrol-related pollutants from the air most efficiently,” Dr Torpy said.

“We know that indoor air quality is often significantly more polluted than outdoor air, which in turn impacts mental and physical health. But the great news is this study has shown that something as simple as having plants indoors can make a huge difference,” Ambius general manager Johan Hodgson said.