Eddie Van Halen believes his throat cancer was caused by a metal guitar pick he used more than 20 years ago, TMZ reported.
The rock star, who has reportedly been "quietly" flying between the U.S. and Germany for years to receive treatment, blames his health issues on an old guitar-playing habit.
TMZ reported that Van Halen would often hold the metal pick in his mouth during shows, a routine he thinks may have exposed him to an assortment of metals. It's the same theory he posited in a 2015 interview with Billboard, when he reflected on a mouth cancer scare in 2000 that caused him to lose one-third of his tongue.
"I used metal picks — they're brass and copper — which I always held in my mouth, in the exact place where I got the tongue cancer," he told Billboard in 2015. "Plus, I basically live in a recording studio that's filled with electromagnetic energy. So that's one theory."
Van Halen, who was a heavy smoker for several years, also gave credence to the idea that drugs and alcohol may have affected his health but added that his lungs were "totally clear" at the time.
"I mean, I was smoking and doing a lot of drugs and a lot of everything," he told Billboard in the same interview. "But at the same time, my lungs are totally clear. This is just my own theory, but the doctors say it’s possible."
TMZ reported that the rock star has been receiving radiation for the past five years and that he's currently in good condition. The cause of his cancer, however, is still up for debate.
Dr. Tom Micklewright, the medical officer at the British medical consultation service Push Doctor, told Insider that Van Halen's health issues were likely not caused by a guitar pick. In an interview published Monday, Micklewright cited the fact that neither copper nor the metals found in brass are considered carcinogenic by the International Agency for Research on Cancer (IARC).
"Copper coils have been used as contraception in the human body for many years without evidence in increased cancer risk," Micklewright told Insider. "In contrast, numerous chemicals contained within cigarettes have been conclusively proven to significantly increase cancer risk, and the more likely cause of his throat cancer."
The doctor added that Van Halen's theory may have come from misconceptions about which metals can be harmful to human health. For example, Mercury has been tied to serious health issues and there is evidence that exposure to cobalt can increase a person's risk of cancer.
"However, the impact of these are far outweighed by the proven effect of tobacco smoke on a vast range of human cancers," Micklewright told Insider. "It's disappointing to see so many publications focus on the metal in this case and miss the opportunity to reinforce the strong public health message about the harms of smoking."