Teal'c reveals his age to be 101 years old in this episode, and will turn 102 "in 47 days". If one assumes that the date at this point in the series is the same as the air date of the episode (January 26th 2001), then this would presumably put Teal'c's birthday (according to Earth calendars) on March 14th 1899.
After Daniel's suicide attempt, O'Neill suggests that they revisit the planet of the week wearing MOPP-2 protective gear. After that discussion, they must have started worrying even more off camera though, because when they actually do go in, the remaining SG-1 members even wear MOPP level 3 protective gear (suit, boots and mask worn, gloves carried.)
When Jack is in the infirmary and says, "All those years of 'Just Say No'," he is referring to the ad campaign prevalent in the '80s and early '90s as a part of the U.S.-led war on drugs, aiming to discourage kids from doing illegal recreational drugs by offering various ways of saying no.