this explains it well
"The aluminium in vaccines is not a heavy metal. It is not even in metallic form as portrayed by vaccine fearmongerers. It is in the form of a salt, usually aluminium hydroxide. The aluminium in aluminium hydroxide is not readily bioavailable and retention is extremely low from both ingestion and injection.
Aluminium salts that you ingest (eg. antacids, buffered aspirin, some processed foods) are mostly excreted before they get to enter the bloodstream. In healthy subjects, less than 0.3% of aluminium that you eat is absorbed via the GI tract and the kidneys effectively eliminate aluminium from the body. Intravenous infusion of products containing aluminium (ie injection directly into the bloodstream via a drip connected to a vein, as with intravenous nutrition pouches for patients in a hospital) or renal dysfunction are the only real scenarios where aluminium has the potential to accumulate.
Once aluminium is in the bloodstream, it is processed similarly regardless of the source. It just depends on the amount received and if the kidneys can keep up. Continuous infusion, we are talking litres here, of a nutrition product delivered directly into the bloodstream, is much more of a deal than a miniscule amount of aluminium hydroxide in a 0.5 ml vaccine injected into muscle. Most of the injected aluminium from vaccines will eventually enter the bloodstream, but it’s not taken up readily by the cells, it is not bioavailable.
Only a very tiny percentage of it will be “dissolved” in the blood – it’s in the form of precipitate bound to carrier proteins. Approximately 89 percent of this aluminium is processed by binding to a protein called transferrin, and the rest is bound to citrate. The majority of the bound aluminium will be processed and eliminated through the kidneys, a small amount through bile and faeces, and a tiny amount is retained in tissues of the body.
About 50% of the aluminium in the bloodstream is eliminated in less than 24 hours, more than 75% is eliminated within two weeks and even more over time. A diminishingly small amount may be retained. But we’re talking about a fraction of two hundredths of bugger all. The ability of the body to rapidly eliminate aluminium hydroxide accounts for its excellent record of safety as a vaccine adjuvant."
aluminium is only a problem with long term exposure ie an intravenous drip or a workplace exposure.