The US National Institute for Occupational Safety and Health has recommended making Las Vegas casinos smoke-free to ensure that air within such properties is safe for workers to breathe.

According to the organisation, indoor air quality tests and biomarker assessments carried out on 124 card dealers in Bally’s, Caesars Palace and Paris casinos on the Las Vegas Strip revealed that workers were exposed to dangerous levels of second-hand smoke.

Responding to the findings, Cynthia Hallett, executive director of Americans for Nonsmokers’ Rights, said: "Casino workers deserve the same rights as other workers, including the right to a healthy, safe workplace, free from toxic second-hand smoke.

"After the release of this report, we hope to see casino workers protected by strong smoke-free workplace laws throughout the country."