"Those hot dry winds that come down through the mountain passes and curl your hair and make your nerves jump and your skin itch. On nights like that every booze party ends in a fight. Meek little wives feel the edge of the carving knife and study their husbands' necks. Anything can happen."

— Raymond Chandler in Red Wing



An ion is a charged atom or molecule. A negative ion has an extra electron and a positive ion is missing an electron. In nature, an average of one atom in 1016 is ionized... about 1,000 to 2,000 per cubic centimeter, roughly balanced between negative and positive ions.

While positive ions affect us negatively, negative ions have a positive effect. Under certain natural conditions, positive ions dominate. When a wind blows over a desert, it stirs up dust. The dust, being positively charged, attaches to the negative ions and they tumble out of the airstream, leaving a wind rich in positive ions. The Santa Ana winds of Southern California (referred to by Mr. Chandler above) and the Swiss foehns are examples of these "evil winds that blow no good." The Swiss and Austrians report dizziness, nausea, depression, and migraines along with an increase in crime, suicides and accidents as a result of foehn winds. It is an interesting fact that Austrian judges have been known to hand criminals a lighter sentence if the foehn is cited as mitigating evidence. The positive-ion-rich mistrals of Arles were quite likely a contributing factor in Vincent Van Gogh's ear-slashing depression (although the mono-diet of coffee and absinthe may also have played an important role).

On the other hand, there are no known ill effects related to an abundance of negative ions. Quite the contrary: negative ions are known to stimulate plant growth, purify air, kill bacteria, relieve hay fever, dispel fatigue, lift depression, increase productivity, and promote a general sense of well being. In nature, negative ions are produced by radioactive gasses, cosmic radiation, falling water, plants, and ultraviolet rays. They are found in abundance at the seashore, in forests, near waterfalls and on mountains.

It follows that we would want the air of our homes to be like natural air in its most nurturing form, rich in negative ions. In fact, the air in most conventionally built homes is just the opposite. Whereas 1,000 negative ions per cubic centimeter is considered the minimal optimum condition, it is not unusual for indoor air to have fewer than 100 ni/cc. This is because the conventional home is full of positively charged surfaces that will "leach" negative ions out of the airstream. These include metal ductwork, plastics, fluorescent lighting, synthetic finishes and furnishings, and computer terminals. The problem is further aggravated if the outdoor air is polluted. Thus, eliminating as many of these elements as possible in the home will help to minimize the depletion of negative ions.

Although you can buy machines to produce negative ions, many of them also generate ozone, which can be damaging to our airways. The over-arching philosophy of Building Biology is to work with nature to build-in or facilitate the desired conditions rather than apply a mechanical Band-aid with the associated impacts of energy use and noise. The shower is a good negative-ion generator and perhaps that is why we sing there. Radiant heating, fire, an abundant supply of fresh outdoor air, fountains, salt lamps, natural finishes and furniture and plant-life will all help create an enlivened, negative-ion-rich home for our positive well-being.



Paula Baker-Laporte FAIA is an architect, a certified Building Biology practitioner, and principle of Baker-Laporte and Associates and EcoNest Design. She is primary author of Prescriptions for a Healthy House and co-author with husband Robert Laporte of Econest: Creating Sustainable Sanctuaries of Clay, Straw and Timber.