Cerium

Cerium is inhaled, remaining in the lungs for a time before moving to the bones and liver.
Cerium is of low to moderate toxicity. Exposure to cerium may occur through inhalation of cerium or fumes from cerium fires, which are toxic. High levels may lead to cancers of the bone, liver and nasal cavities. Workers exposed to cerium have experienced itching, sensitivity to heat, and skin lesions. Animals injected with large doses of cerium have died due to cardiovascular collapse.
Cerium has numerous commercial applications such as catalysts, additives to fuel to reduce emissions, and additives to glass and enamels to change their color. Cerium oxide is an important component of glass polishing powders and phosphors used in screens and fluorescent lamps.