Sometimes, it’s the plants themselves that take in harmful gases alongside carbon dioxide and neutralise them during photosynthesis or simply absorb them into their waxy cuticles. Other times it’s the microbes in the potting soil that are doing all the hard work.
But you can’t just place tubs of soil around your house! Potting soil microbes only turn into miniature air janitors when activated by growing plant roots. So, it really does need to be plants in soil to make a difference—and what a big difference they make!
Plants can even remove the low levels of carbon monoxide that are produced by cooking with gas, lighting an open fire or being situated next to a busy road due to the exhaust fumes.
In humans, carbon monoxide is harmful because it binds to the haemoglobin in our red blood cells more readily than oxygen, which prevents oxygen from being transported to our vital organs.
It is harmless—and even beneficial—to plants, however, because they, of course, have no haemoglobin and don’t need to transport oxygen to their cells.