The EWG, or Environmental Working Group recently did a study on the safety of cookware coated with Teflon and other non-stick type surfaces. The findings included the fact that these surfaces can and do break apart and emit toxins into the air when heated to a high degree of temperature. At extremely high degrees the Teflon pans release several toxic gases, carcinogens, environmental pollutants, and MFA, which is a chemical that is lethal to humans even at low doses
These toxins and gases have been linked to hundreds of pet bird deaths and many human illnesses each year. The lungs of birds exposed to these gases hemorrhage and fill with fluid, leading to suffocation. Avian veterinarians have known about the hazards to birds from Teflon fumes. In fact, in 1986, a Chicago based expert on Teflon toxicosis called Teflon fumes a leading cause of death among pet birds. This phenomenon occurs even under ordinary cooking conditions. Bird deaths occur during or immediately after cooking with Teflon coated pans.
As you can see by reading the links connected with this article, Teflon not only affects birds, but human beings as well. Flu like symptoms have been reported by Teflon users. The manufacturers of Teflon claim that these toxins and gases are only released under extremely high temperature conditions which normally would not be reached while cooking in a normal manner. The EWG, however, found that just preheating a generic non-stick coated pan on an electric stove burner set on high, more than met the criteria for the danger levels indicated by the manufacturer.
Given these facts, I know I for one have replaced all of my cookware which contained non stick surfaces. I did not choose aluminum because of the issues concerning aluminum toxicity. See article:The Dangers of Aluminum Toxicity Stainless steel seemed to be the best bet. Check out the link connected to this article regarding the safety of stainless steel cookware. I have several wonderful cast iron pots and pans that I use also. The only problem with the cast iron variety is that it is very heavy, and can be cumbersome to deal with while cooking on a stove top.