With its slim white body and glowing amber tip, it can easily pass as a regular cigarette. It even emits what look like curlicues of white smoke. The Ruyan V8, which produces a nicotine-infused mist absorbed directly into the lungs, is just one of a rapidly growing array of electronic cigarettes attracting the scrutiny of world health officials. Marketed as a healthier alternative to smoking and a potential way to kick the habit, the smokeless smokes have been distributed in swag bags at the British film awards and hawked at an international trade show.