Prolific shedding of magnetite nanoparticles from banknote surfaces

Here, we use magnetic methods first to quantify the content of strongly particles banknotes (US dollars, USD, and British pounds sterling, GBP), then examine possibility their release from handled banknote surfaces. The particles, remanence measurements, for USD paper GBP is high; greater, example, than that in vehicle engine-exhaust emissions, similar airborne roadside particulate matter (PM). Our analyses banknotes, ink pigment widely used printing, reveal not only are highly magnetic, but also nano-sized readily prolifically shed surfaces (especially banknotes). A common practice, prior increased automation, was bank tellers count by licking a finger adhere each successive counted note, thus speed up manual counting process. Given rate particle shedding reported here, this traditional procedure must have resulted prolific transfer iron-rich nanoparticles both fingers thence tongue. We hypothesise that, pre-automation, magnetite other metal-bearing were repetitively frequently ingested tellers, subsequently entered brain directly via taste nerve pathway, and/or indirectly systemic circulation neuroenteric system. This hypothesis may plausibly account currently unexplained association between elevated neurodegeneration-related mortality odds ratios specific occupation.