For years now, asbestos has been a building boogeyman. We know people used to use a lot of this stuff, we know it's bad for people and we know we're still finding it in old buildings, requiring careful cleanup.Now, the much-maligned material is getting something of a comeback: The Environmental Protection Agency is reportedly easing up on asbestos regulation. While the agency is maintaining a ban on the substance, it could allow for asbestos to be used on a case-by-case basis in construction.So what is this stuff, and why is it suddenly back?From the Ground to Ancient Greece"Asbestos" is a generic term for six types of naturally occurring minerals. The types that are used in construction are white, blue and brown varieties, known as chrysotile, crocidolite and amosite. It's found all over the world, but the biggest deposits lie in Canada and Russia. There's even a small Canadian town, home of a historic asbestos mine, that named itself in honor of the mineral.The mineral was once seen as something of a miracle product. Unlike other minerals, it can easily be spun into thread for cloth. And unlike like other types of cloth, it is remarkably fireproof. Asbestos was crucial to ancient Greek society, where the stuff was used within pottery, napkins, insulation, clothing and even symbolic eternal flames within temples dedicated to Greek gods, which would burn slowly on asbestos wicks. In fact, the word "asbestos" comes from Greek, roughly translating to "inextinguishable."After the fall of Greece and Rome — and centuries as a party trick and friend to scam artists trying to sell its mystical powers — asbestos came back into favor during the Industrial Revolution. It was the perfect insulation for hot things like steam pipes, turbines, ovens and kilns. Its heat resistance and strength made it perfect for brake and clutch linings on trains. A Dark SideBy the 1920s, asbestos was reaching a peak in popularity. Mines around the world, operated by men, women and children, were pushing out more 109,000 metric tons annually. But as its use grew, so, too, did growing medical concerns about asbestos.The first mention of asbestos in a medical journal came in the British Medical Journal in 1924, when Willian Cooke was studying illness and death from fibrosis of the lungs and tuberculosis among workers in an asbestos spinning room. Soon, the term ‘‘asbestosis’’ began to crop up in medical circles. Following cases of sickness in Glasgow asbestos factories, a young Scottish medical inspector named Edward Merewether began studying the material and concluded that there was a "definite occupational risk among asbestos workers as a class."Merewether's investigation was limited to inhaling asbestos dust, and the British government instituted regulations in 1933. The problem seemed to be solved.It was not. By midcentury, when product lines of asbestos had grown more than ever, the disease became increasingly associated with two diseases: lung cancer and a once-obscure form of cancer, mesothelioma.The work of Irving J. Selikoff, who worked at Mount Sinai Medical Center, in Manhattan, was crucial to the global understanding of asbestos. Studying 17 patients at an asbestos plant in New Jersey, "it became clear as we were following these people that they were dying of cancer," he told The New York Times. Soon thereafter, 15 of them were dead, 14 from asbestosis or mesothelioma. A larger study of 17,800 insulation workers only confirmed the facts: Working with or near asbestos meant you were more likely to get cancer.An Era of PushbackEventually, the public protest against asbestos use was overwhelming. The Occupational Safety and Health Administration was formed in May 1971 under the Department of Labor. By August 1971, asbestos regulations were already in place. By December 1971, an "emergency standard for asbestos dust" was implemented.And then came 1989, the year the asbestos industry forever changed. EPA Administrator William K. Reilly, acting under newly elected President George H. W. Bush, announced that over 7 years, the government would place a virtual ban on all asbestos products. Reilly said that asbestos products had left ''a terrible legacy of dead, dying and crippled.''While the 1989 ban proved to be a major blow to the industry, it was far from a death knell. In 1991, despite decades worth of medical history, a court ruled that the EPA had failed to present "substantial evidence" worthy of a complete ban on asbestos products. Asbestos remained banned in five product lines, and new uses were forbidden. Despite implementing the ban in the first place, the Bush administration declined to take the case to the Supreme Court.The mineral remains in products sold today. Don't Call It A Comeback; It's Been Here For YearsThere have always been vocal skeptics of the dangers of asbestos, notably in industries that used the product heavily for insulation. One of these skeptics was President Donald Trump. The 1997 Trump book "The Art of the Comeback" said anti-asbestos efforts were “led by the mob," due to organized crime's rumored involvement in asbestos removal operations. In 2012, Trump tweeted that he believed asbestos would have kept the World Trade Center standing after the 9/11 attacks.In fact, asbestos fireproofing materials were present on 20 stories of the World Trade Center, which used the mineral in some of its construction. About 10,000 people were exposed to a host of toxins, including asbestos, in the wake of the twin towers collapse, which began to have the same effects as it did on miners and factory workers nearly a 100 years earlier. A 2011 study showed that firefighters exposed to World Trade Center dust were nearly 20 percent more likely to develop lung cancer.But the industry remains across the globe. Recently, a Russian asbestos company began using Trump's face on a seal for its products, mentioning the president's long-standing pro-asbestos stance, and cited former EPA Administrator Scott Pruitt's recommendation to let "new uses" of the mineral be considered.