Are there dangers to Teflon and aluminium cookware?
The US Department of Health and Human Services has a nice set of factsheets on aluminum. In brief, and to specifically answer your questions, they point out that:


Aluminum occurs naturally in air, water, soil, and plants.
The amounts of aluminum that we encounter in pots and pans are considered to be safe for healthy people. Cooking acidic foods in aluminum pots increases the amount ingested, but is still considered to be safe; and it still represents many times less aluminum than in over-the-counter antacids, which are also considered safe.
Much of the aluminum we ingest leaves ones body naturally through the digestive system (that is, feces), and is not taken up into the bloodstream. The small amount of aluminum that makes it to our bloodstream is mostly quickly eliminated in urine. Those with kindey problems may not process this bloodstream aluminum as quickly.


Nonstick pan coatings are a little more difficult, probably because they're so diverse. Cookware isn't even mentioned as a source on the factsheet for perflouroalkyls, the chemical which has been mentioned in connection with nonstick pan health issues. The US Environmental Protection Agency FAQ says:


  Consumer products made with perfluorochemicals include some non-stick cookware ... Consumer products made with fluoropolymers and fluorinated telomers, such as Teflon and other trademark products, are not PFOA. PFOA is used as a processing aid in the manufacture of fluoropolymers and can be also be produced by the breakdown of some fluorinated telomers [NB. I assume they mean overheating nonstick pans]. The information that EPA has available does not indicate that the routine use of consumer products poses a concern.