PORTLAND, Ore. — Vaping products, one of the fastest-growing segments of the legal marijuana industry, have taken a hit from consumers as public health experts scramble to determine what’s causing a mysterious and sometimes fatal lung disease among people who use e-cigarettes.

The ailment has sickened at least 805 people and killed 12. Some vaped nicotine, but many reported using oil containing THC, marijuana’s high-inducing ingredient, and said they bought products from pop-up shops and other illegal sellers. The only death linked to THC vapes bought at legal shops occurred in Oregon.

Amid the health scare, the amount of the legal pot industry’s revenue that comes from vape products has dropped by 15% nationwide, with some states, including Oregon, seeing decreases of more than 60%.

Health officials in California, home to the world’s largest legal marijuana marketplace, this week issued an advisory urging people to stop all forms of vaping until a cause is determined. Massachusetts, which like California allows so-called recreational use of marijuana by people 21 and older, went further than any other state, issuing a four-month ban on vape sales.

[Read More @ The Washington Post]