If vapors toxic to humans are produced by the degradation of household cleaning products by bacteria in any landfill, then the health of at least some humans will suffer.
In here http://www.manhattanlsat.com/forums/q8-environmentalist-when-bacteria-degrade-t1014.html, they rule out this choice, because they interpret the use of "any" to mean all.
However I'm confused because I'm accustomed to "any" being used in at least two senses. The first one being used to indicate all -- if someone says "This is true for any student", then he means that it is true for all students.
The second meaning I've seen it used is to indicate at least one. So if I say "If any of you object, then I'll change my mind," then my meaning is that if at least one of you object, then I'll change my mind.
In this particular answer choice, it seems like either meaning (all or at least one) would be plausible, which is problematic since one would rule out this answer choice, while the other would make it seem like the correct answer. Is there something I'm missing here? Thanks!