For years, scientists and Egyptian authorities have fretted that a slew of brown spots scattered atop paintings lining the walls of King Tutankhamen’s burial tomb in Egypt were caused by tourists visiting the popular site. But this week, a team of scientists from the Getty Conservation Institute in Los Angeles wrapped up a study of the wall paintings and found that the array of blotches are nothing to worry about. After closely comparing a photograph of the tomb taken in the 1920s to the site now, and performing microscopic and chemical testing, the team announced that the spots have a microbiological origin––meaning, in other words, it’s just some dead mold. Prior to this conclusion, many worried that the humidity emitted by sweaty tourists was to blame, or that bat droppings were at the root of the brown dapples. “Now we can say they are mold and fungus but they are dead, no life in them at all,” Neville Agnew, the project’s director, told the New York Times. Still, the harmless spots will be sticking around since they have embedded themselves into the paint, so removing the spots would mean removing the artwork. The research, organized by the Getty and Egypt’s Ministry of Antiquities, is a part of a nine-year-long, multimillion-dollar undertaking to study and protect the tomb from further deterioration. In addition to this test, the tomb has seen the addition of ramps, railings, a ventilation system, and a cap to the amount of visitors allowed inside the space at once.