Well, Byakuren's magic was specifically geared towards IMPROVING her health and physical attributes. That probably counteracted any poisoning that the reagents caused.
Not sure why Alice is up there as her type of magic is focused around dolls and seems somewhat non-traditional. That and nothing was said of Alice being in remotely poor health, just rather anti-social.
Patchy's very traditional and those materials might be involved with her frail state, among with spending all her time in a big old library.
Hijiri I get the impression that she used a different brand than either of them.
Marisa is VERY non-traditional; I doubt she messes with such things much as opposed to various mushrooms.
I think all of them (except for Byakuren) had to have come in contact with dangerous substances when doing alchemical/magical experiments for whatever purpose at some point. There´s always some dubious chemistry behind all that lighting and sparkling of magic.
As a magician, even Alice have to make research in all available ways. And we´ll probably never know if some chemical poisoning is somewhat guilty for Patchy´s health problems. But those two are magicians as a species, Marisa on the other hand might be more vulnerable to this kind of poisoning. But who knows.
Alice's magic is most definitely traditional and alchemy based. The concept/theory of imbuing dolls with magic is very old and well "documented". Did we all forget how Alice was using voodoo dolls in Bohemian Archive in Japanese Red?
Mercury and arsenic are usually used as materials for magic.In most cases, we make great efforts to prevent it from entering our bodies, but it always makes its way in little by little nonetheless.throwing it away...And I am sure that there is plenty of arsenic in that "gold" you are holding.Arsenic is extremely poisonous to humans.What is arsenic anyway?And arsenic too!?What!? Mercury!?tears~This is why most of us magicians have problems with our constitution!
