One thing worth considering is we in fact have a model for this: tattoos, and tattoo-ink. This is in fact the mechanism by which tattoos are removed by laser (the particles are exploded into ones small enough for the immune system to carry off quickly - as opposed to the gradual fading with time which happens).
One tattoo is a larger exposure of particulate contaminants to the skin then anyone will ingest in a lifetime from the environmental contamination.
One tattoo is a larger exposure of particulate contaminants to the skin then anyone will ingest in a lifetime from the environmental contamination.