Houseplants are, of course, the essence of green, and their
presence is beneficial. Their appearance in rooms has been found
to purify indoor air. [1] In addition to eliminating noxious
gases and reducing carbon dioxide,[2] plants also produce oxygen
and balance indoor humidity, resulting in air that is more like
natural outdoor air.[3]  It's the methods used to grow plants
that are the problem: The US spends more than $5 billion a year
(including outdoor gardening) on fossil-fuel-derived fertilizers
that leak chemicals and accelerate the release of nitrous
oxide—a greenhouse gas.[4] Insecticides are also dangerous to
the environment: The US Environmental Protection Agency (EPA)
has classified ingredients such as permethrin as a likely
carcinogen.  Related health issues  The EPA cites indoor air
pollution as one of the top five public health threats in
America due to artificial materials like synthetic fibers and
plastic, which emit harmful formaldehyde, trichloroethylene
(TCE), benzene, and other volatile or