"High levels of aluminum in the body are definitely not healthy, and the byproducts of incinerated foil that is inhaled are not healthy, are possibly carcinogenic. The soot that accumulates on aluminum from flame is also a lung irritant.
Aluminum: A naturally occurring element that makes up about 8% of the surface of the earth and is always found combined with other elements such as oxygen, silicon, and fluorine. Aluminum is is the most common metallic element in the earth's crust but has no clear biologic role. Everyone is exposed to low levels of aluminum from food, air, and water. Exposure to high levels of aluminum may result in respiratory problems (aluminosis). Inhalation of bauxite (aluminum ore) fumes may cause pulmonary fibrosis. Aluminum in the bloodstream may lead to neurological symptoms and may be fatal.
Aluminum toxicity occurs in people with renal insufficiency who are treated by dialysis with aluminum-contaminated solutions or oral agents that contain aluminum. The clinical manifestations of aluminum toxicity include anemia, bone disease, and progressive dementia with increased concentrations of aluminum in the brain. Prolonged intravenous feeding of preterm infants with solutions containing aluminum is associated with impaired neurologic development."