Some websites are falsely claiming that NASA has "confessed" to "dosing Americans" with lithium and other chemicals.
On its website, NASA explains that it does use the materials for wind experiments launched on sounding rockets to the upper atmosphere. The space agency says "the small amounts of vapor tracers that are released in space are not harmful to people or life on the ground."
It notes that the metals used — barium, lithium and aluminum compounds — are also used in fireworks. NASA says a typical July Fourth fireworks display releases far more of the material, much closer to the ground.
NASA compares its tests to releasing a harmless dye into a river or stream to study the currents.