Outdoor smoke levels at hospitality venues have soared after New South Wales banned smoking indoors, according to research showing club patrons and employees face smoke levels up to 36 times the recommended exposure limits.

The research from PhD student Maggie Davidson and her supervisor, Dr Sue Reed, from the University of Western Sydney which will be presented at the Safety In Action conference in Melbourne tomorrow.

It found that while indoor air quality has markedly improved, smokers returning inside still bring their smoke inside with them.

Davidson compared air quality samples collected at licensed premises before and after the bans and found the average level of smoke outdoors was close to four times higher at some clubs after the bans took effect.

At the same time, indoor air quality improved dramatically, with average smoke levels falling by as much as 96 per cent but high levels were still detected for short periods.

“At two of the venues, the spikes of very high indoor PM2.5 levels strongly correlated to large groups of smokers coming back inside at once," Dr Reed said. “Smokers who've just finished a cigarette are still exhaling smoke and carry a cloud around them.””From an occupational health and safety perspective, things have improved indoors but hospitality workers still have to spend a lot of time outdoors breathing in these hazardously high levels of smoke.”

The Safety in Action Conference is being held by the Safety Institute of Australia in partnership with WorkSafe Victoria and is running alongside the Safety In Action trade show from April 20 to 22 at the Melbourne Convention Centre.