Plants are the lungs of the earth: they produce the oxygen that makes life
possible, add precious moisture, and filter toxins. Houseplants can perform
these essential functions in your home or office with the same efficiency as
a rainforest in our biosphere.

In research designed to create a breathable environment for a NASA lunar
habitat, noted scientist Bill Wolverton discovered that houseplants are the
best filters of common pollutants, such as ammonia, formaldehyde and
benzene - chemicals released by furniture, carpets, building materials and
photocopiers and then trapped by closed ventilation, leading to a host of
respiratory and allergic problems now called Sick Building Syndrome.

Here Dr Wolverton shows you how to grow 50 plants as accessible and
trouble-free as the tulip and Boston fern. He rates each plant for its
effectiveness in removing various pollutants.

Studies show we spend around 80% of our lives indoors which means good
indoor air is vital for good health. How to Grow Fresh Air will show you how
to purify the environment that has the most impact on you.