I got this quote off the WideScreen Museum page, about the history of lenses:

This one has an unusual and regrettable legacy. It should not have been made for countless reasons, specifically, John Wayne was not talented enough to pass himself off as a Mongol, the story line was dopey, and worst of all it is quite likely that this film cost many of the cast and crew their lives. Filmed in the Nevada desert in 1956 near a site where atmospheric nuclear weapons testing was being conducted, the film holds the record for the number of people that ultimately died of cancer, including: John Wayne, Susan Hayward, Dick Powell, Pedro Armendarez, Agnes Moorehead, and probably others that are not so well known. Studio owner Howard Hughes died many years later, but his death was caused by terminal weirdness.