"The Numbers Guy" blog examined the roots of a claim attributed to the World Health Organization — that 10 percent of all drug sales are of counterfeit drugs. That attribution which has appeared in many news articles and blogs may stem from a 2002 editorial in the British Medical Journal, which in turn cites a 1999 study that didn’t make that claim. "It is a wild guess made by someone," said Albert Wertheimer, a professor in Temple's School of Pharmacy, "that, now, everyone quotes.” He said substandard drugs produced by licensed manufacturers may be as big a problem, or even bigger, but it is not the subject of a World Health Organization task force.