What happens in Vegas, stays in your lungs: an assessment of fine particulate matter in casinos that prohibit and allow smoking in Las Vegas, Nevada, USA.

Despite robust evidence about the harms of SHS, tens of thousands of casino employees and tens of millions of tourists are exposed to high levels of SHS in Las Vegas casinos annually, with PM2.5 levels 5.4 times higher in gaming areas when compared with a smoke-free casino. The only way to protect people from SHS exposure is to prohibit smoking in all indoor areas.