Editorial: The lack of health research into marijuana makes it hard to tell people whether it is safe

In advance of the legalization of recreational marijuana sales in California on Jan. 1, there have been lots of debates over the details of the cannabis business. How many feet should pot shops be from schools or daycare centers? How many acres may a marijuana farmer cultivate? Who should be eligible for a license to sell and who shouldn't?

But there's been much less discussion over an equally important question raised by the end