Richard Carmona, US surgeon general from 2002 to 2006, has joined the board at e-cigarette maker NJoy in a move that may lend credibility to the product as a safer alternative to cigarettes, the company said.

Carmona will advise NJoy on public health and regulatory matters, the company said on its website. NJoy is based in Arizona and sells its product from more than 50,000 retail locations in the US. (ci)