Note that the tower doesn't really look like that picture in the nypost - it's a much more portable looking affair: https://maps.app.goo.gl/Y9QMBDPnazGT1cgj9
https://www.nytimes.com/1981/12/04/us/around-the-nation-two-...
On a serious note, a short term exposure like this probably wouldn't be that harmful*, and they seem like risk-takers already so the hazards are factored in for them.