“A holiday from the facts.” That’s how the antagonist of "Brave New World" describes the wonder drug soma. The phrase might equally apply to U.S. marijuana policy. Since California first legalized medicinal cannabis in 1996, the U.S. pot industry has morphed into a $40 billion behemoth. Weed is now legal in 24 states for recreational purposes and in 40 for medical use. About 15 percent of Americans report partaking; close to 18 million are daily or near-daily users, on par with alcohol. Accompanying this boom has been a proliferation of pot-adjacent products — vapes, oils, edibles, gummies, concentrates, tinctures, fizzing multicolored soft drinks infused with staggering levels of THC — that are subject to varying state-by-state regulations and essentially no federal product-safety standards. (A law passed in November aims to curtail such products but may not be enforced anytime soon.) Amid this haphazard experiment, some inconvenient facts are emerging. For one, evidence has been piling up that marijuana poses significant risks to public health, particularly for young people.