Table 2: Estimates of daily and weekly intakes of Al in humans [28, 74].

Major sources of Al exposure in humansDaily Al intake (mg/day)Weekly Al intake (mg/day)÷PTWI (1 mg/kg/bw; for an average 70 kg human PTWI = 70 mg)Amount delivered daily into systemic circulation (at 0.25% absorption rate)

Natural food1–10 [2, 8, 2326]7–700.1–12.5–25 μg
Food with Al additives1–20 (individual intake can exceed 100) [3, 5, 18]7–140 
(700)
0.1–2 
(10)
2.5–50 μg  
(250 μg)
Water0.08–0.224 [2, 8, 21]0.56–1.560.008–0.020.2–0.56 μg
Pharmaceuticals (antacids, buffered analgesics, antiulceratives, and antidiarrheal drugs)126–5000 [1, 2, 8]882–35,00012.6–500315–12,500 μg
Vaccines (HepB, Hib, Td, DTP)0.51–4.56 [9]NANA510-4560 μg
Cosmetics, skin-care products, and antiperspirants70 [1, 9]490NA8.4 μg (at 0.012% absorption rate) [10, 11]
Cooking utensils and food packaging0–2 [2]0–140–0.20–5 μg

PTWI (provisional tolerable weekly intake) is based on orally ingested Al, generally only 0.1–0.4% of Al is absorbed from the GI tract, however, Al may form complexes with citrate, fluoride, carbohydrates, phosphates, and dietary acids (malic, oxalic, tartaric, succinic, aspartic, and glutamic), which may increase its GI absorption (0.5–5% [70, 82]). Coexposure to acidic beverages (lemon juice, tomato juice, and coffee) also increases Al absorption as well as conditions of Ca2+, Mg2+, Cu2+, and Zn2+ deficiency [70, 8385].
A single dose of vaccine delivers the equivalent of 204–1284 mg orally ingested Al (0.51−5.56 mg), all of which is absorbed into systemic circulation [86, 91]. Al hydroxide, a common vaccine adjuvant has been linked to a host of neurodegenerative diseases; it also induces hyperphosphorylation of MAP tau in vivo [44, 45, 87].
The risk of antiperspirants is both from dermal exposure and inhalation of acrosols. Al is absorbed from the nasal epithelia into olfactory nerves and distributed directly into the brain [88, 91].