I enjoy the works of playwright Athol Fugard, but this name sounds too much like an insulting term for the anus. In Massachusetts there's also a town called Athol, which is the butt of a lot of jokes.
I actually believe that this has an oddly handsome hue to it... Unfortunately it has been tainted unusable in most English-speaking countries (especially the United States). The explanation? "Athol" resembles a certain crude "term" for someone's rear-end. "Ahth-ol.. Ath-ol.. Ath-hole," if you understand. Whether or not the mature generation interprets it as so-- school-grade children are merciless, and this should be seriously taken into consideration before you make a written-in-stone decision to dub your son.