Levels of second-hand smoke in Scotland’s prisons fell by more than 80 percent in the week after smoking was banned, according to new University of Stirling research.

The study confirms the positive impact of the smoke-free policy, introduced in November 2018, on the air quality within Scotland’s 15 prisons. The researchers compared smoke levels to measurements taken in 2016.

The study was led by Stirling’s Institute of Social Marketing (ISM), and involved the University of Glasgow and conducted in partnership with the Scottish Prison Service

Dr Sean Semple, Associate Professor at the ISM said: “We collected more than 110,000 minutes of second-hand smoke measurements from across the prison estate in the week that the smoking ban was introduced – and we compared these readings with measurements taken as part of the Tobacco in Prisons Study (TIPS) research in 2016.

“Our study shows improvements in the levels of second-hand smoke in every prison in Scotland, with an average fall of 81 percent. This is similar to the scale of change observed when pubs became smoke-free in 2006 – and the concentrations of fine particles in prison air has now reduced to levels similar to those measured in outdoor air in Scotland.

“This research confirms that exposure to second-hand smoke has been drastically reduced and, ultimately, this will have a positive impact on the health of prison staff and prisoners.”

Smoking has been banned in most enclosed public spaces in Scotland since 2006, however, prisoners were still permitted to smoke in their cells as long as their doors were closed. This situation changed on November 30, 2018, when smoking was banned in all prisons in Scotland.

It was estimated about 72% of Scottish prisoners smoked regularly before the ban was introduced.

The researchers used air quality monitors to measure fine particulate matter in each prison since 2016 and did so again during the week when the ban came into force.

The results showed that airborne levels of fine particles declined substantially in every prison between 2016 and December 3, 2018, the first full working day following the introduction of the ban. The overall median reduction in particle concentrations was 81 percent across all prisons.

A Scottish Prison Service spokesman said "All Scottish prisons went smoke-free on November 30 2018, and there have been no significant incidents as a result.

"This amazing achievement is a testament to the contribution made by all of our staff, especially those on the front line, and the cooperation of those in our care."

Debbie Sigerson, Organisational Lead for Tobacco in NHS Health Scotland said: “Smoking rates in prisons were much higher than they are outside. It was anticipated that creating a smoke free environment in prison would contribute to addressing this health inequality, and that the health of people who live and work there would be improved.

“We are delighted that the results from this study, early on in the implementation of smoke free prisons, shows that one factor that impacts on that harm – exposure to second hand smoke – has significantly reduced. Everyone has a right to live in a smoke free Scotland and today’s results show that we are one step further along the way to getting there.”

The study The impact of implementation of a national smoke-free prisons policy on indoor air quality: results from the Tobacco in Prisons Study was published in the British Medical Journal’s Tobacco Control and is the first of its kind to examine second-hand tobacco smoke concentrations across an entire prison estate where smoking is prohibited in all establishments.