just want to put it out there that no I don't believe in exposing children to sexual content, my kids will be sheltered for as long as I can control it - however.....
At a primary school library there will be no books containing this sort of thing. At intermediate and high school, yes of course there will, and I have to repeat, if your kid is attending public intermediate or high school they are getting nothing new from those books. I agree 100% with what Aeh says about the info being academic.
My kids attended a K-8 school. So the library contained books that went well into high school literature. Even the elementary schools around here go K-6. Advanced 6th grader readers should have access to teen material & 'adult' reading level books. So I wouldn't say that a elementary library might not have books with mature content in them. I actually sure hope they do.