Air in Scotland’s prisons 90% cleaner, due to smoke-free policy

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Scotland’s smoke-free prisons policy is protecting the health of prison staff and those in custody – with the majority no longer exposed to second-hand tobacco smoke, according to a new study.

The second-hand smoke research – led by the Universities of Stirling and Glasgow – found levels of second-hand smoke (SHS) fell 90 percent following the policy’s introduction.

The improvement means that air inside Scotland’s prisons has particle concentrations similar to most smoke-free environments – in some cases, cleaner than the air outdoors – and effectively eliminates the risk from SHS for staff and prisoners.

Significantly, the findings dispel concerns, raised before the policy was introduced, that smoke-free prisons would be difficult to maintain in the long-term.

Professor Kate Hunt, Dr Sean Semple and Dr Ruaraidh Dobson, of the Institute for Social Marketing and Health (ISMH) at Stirling, co-led the study alongside Dr Evangelia Demou, of the MRC/CSO Social and Public Health Sciences Unit at the University of Glasgow.

Kate Hunt

Professor Kate Hunt, of the University of Stirling co-led the study.

Professor Hunt said: “This is the first comprehensive international study to objectively measure second-hand smoke in prisons across a country before, during and after the introduction of a smoke-free policy. Our work confirms that such a policy change can be successfully implemented to eliminate occupational exposures to second-hand smoke, which is linked to many illnesses, including cardiovascular disease, cancer, and chronic obstructive pulmonary disease.

“Our findings are highly relevant for other jurisdictions and prison services considering organisational and policy changes relating to indoor smoking.”

Air quality

Smoking has been banned in most enclosed public spaces in Scotland since 2006, however, prisons in Scotland only became smoke-free on November 30, 2018. Between those dates, prisoners were permitted to smoke in their cells and in some outdoor areas – meaning those in custody and prison staff remained exposed to SHS.

The research team used air quality monitoring equipment to record measurements before the policy’s introduction (2016); during the week in which the policy was introduced (November 2018); and six months later (May 2019). On each occasion, fixed-site measurements were taken in the same residential hall in each prison in Scotland over a six-day period, and in 2016 and 2019, in other areas during specific tasks, for example: cell searches, building maintenance, and serving meals.

A previous paper reporting on the November 2018 measurements found that SHS levels fell by more than 80 percent in the week following implementation. However, the latest research findings confirm adherence to the policy and its effectiveness over a longer timeframe.

The latest results show  a reduction from 2016 (pre-ban) to 2019 (post-ban) of more than 91 percent in the concentrations of fine particulate matter (PM2.5) – a way of measuring for SHS – for the fixed-site measurements, and more than 90 percent for the mobile measurements.

Prior to the ban, measurements had indicated that some staff groups experienced higher exposure than others, depending on the shifts they worked and the tasks they undertook. However, the latest findings confirm that there is no longer a disparity in exposure.

Dr Evangelia Demou
Dr Evangelia Demou
University of Glasgow
These results show that very large reductions of second-hand smoke have been maintained over a six-month period – and, in some cases, the PM2.5 level is lower than some outdoor locations.

Dr Demou said: “Prior to the implementation of the policy, many people were concerned that it would be difficult to ban tobacco in prisons due to the very high levels of smoking in the prison population. However, these results show that very large reductions of second-hand smoke have been maintained over a six-month period – and, in some cases, the PM2.5 level is lower than some outdoor locations.

“This confirms that people who live and work in prisons are now protected from second-hand smoke.”

A spokesperson for the Scottish Prison Service said: "The SPS welcomes the research and is pleased with the success of our move to smoke-free prisons and the positive impact it has had on both those in our care and our staff and visitors."

The study – funded by the National Institute for Health Research – forms part of the wider Tobacco in Prisons study, led by Professor Kate Hunt, of the ISMH. Further work is ongoing to examine the health effects of the SHS reduction on prison staff and those in custody, and to understand how both groups feel about the move to smoke-free prisons.

The paper, From smoking-permitted to smoke-free prisons: a three-year evaluation of the changes in occupational exposure to second-hand smoke across a national prison system, is published in Annals of Work Exposures and Health.

The research team has also written an article for the University's Policy blog, which can be read here.

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