Acute exposure to low doses of formaldehyde may cause burning of the eyes, nose and throat, tearing, nausea, dizziness, cough, chest pain and shortness of breath. Chronic exposure has been causally associated with headache, drowsiness, memory loss, menstrual irregularities and two types of human cancer.

Testing for formaldehyde in home air should be done when all doors and windows are closed and heat and humidity are high, to eliminate false negative readings. When the source of formaldehyde cannot be removed (e.g. in mobile homes), surface treatments to seal pressed-wood sources may significantly reduce emissions.

(6) Volatile Organic Compounds (VOCs). These are invisible gases which are emitted from paints, adhesives, carpeting, wall coverings, new furniture, building materials, solvents, cleaning solutions, copy machines, and laser printers. Studies using experimental chambers have shown that VOCs can cause irritation of the respiratory system in humans and animals at levels which are one hundred times weaker than the World Health Organization Indoor Air Guidelines. Controlled experiments with people who suffer from Sick Building Syndrome confirm that VOC exposure can also cause headache, fatigue and difficulty concentrating. Dozens of VOCs have been identified in residential air. Some of the VOCs found in indoor air, such as benzene derivatives, may promote cancer in humans. Concern over the safety of cleaning solutions and VOCs has created a demand for less toxic alternatives. Information about these products can be obtained from sources in listed in the appendix of The Four Pillars of Healing. Good dust control (as described in section 2 above) will lower VOC levels, because dust particles absorb VOCs and increase their concentration in the air.

(8) Purify your water. Chlorination of municipal water supplies was first introduced in Jersey City, New Jersey, in 1908. It dramatically reduced the death rate from typhoid fever, a bacterial infection which is spread through drinking water. But chlorination has drawbacks. Chlorine reacts with organic matter dissolved in water to form cancer-promoting substances like the trihalomethanes (THMs), of which the best known is chloroform. Drinking chlorinated water increases the risk of developing cancer of the rectum or the bladder, the risk increasing the more water is drunk. THMs are volatile; they evaporate from water during cooking or when showers are running and contaminate the air in homes. A preventive solution: filter your tapwater through activated charcoal, which removes the vast bulk of chlorinated compounds, before you boil it. Shower-head filters that remove chlorine will help to prevent the release of chloroform gas during hot showers.

(9) Refresh the air in your home/office. Laser printers, copiers and fax machines all release VOCs into the air when they operate. Maintain a source of fresh air, like an open window, and run an exhaust fan or an air purifier that contains a charcoal filter. Ordinary air purifiers remove dust and pollen but not chemicals. Don't make yourself a victim.