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Smoke-free prisons in England: indoor air quality before and after implementation of a comprehensive smoke-free policy

Jayes, Leah R.; Murray, Rachael L.; Opazo Breton, Magdelena; Hill, Christopher; Ratschen, Elena; Britton, John


Leah R. Jayes

Christopher Hill

Elena Ratschen

John Britton


High levels of particulate pollution due to second-hand smoke (SHS) have previously been recorded in English prisons. As part of an evaluation to ascertain whether a new comprehensive smoke-free policy introduced in the first four prisons in England was successfully implemented, this study compares indoor air quality on prison wing landing locations three months before and three months after going smoke-free.


An indoor air quality monitoring study, comparing SHS levels before and after a comprehensive smoke-free prison policy.


The first four prisons in England to implement a comprehensive smoke-free policy.

Primary and secondary measures

We compared concentrations of airborne particulate matter [less than] 2.5 microns in diameter (PM₂.₅), as a marker for SHS, on wing landing locations three months before and three months after the smoke-free policy was implemented. Static battery operated aerosol monitors were used to sample concentrations of PM₂.₅ on wing landings.


After discarding data from monitors that had been tampered with we were able to analyse paired data across four prisons from 74 locations, across 29 wing landing locations, for an average sampling time of five hours and eight minutes. When comparing samples taken three months before with the paired samples taken three months after policy implementation (paired for prison, day of the week, time of day, wing location and position of monitor), there was a statistically significant (p [less than] 0.001) 66% reduction in mean PM₂.₅ concentrations at each of the four prisons sampled, from 39 µg/m³ to 13µg/m³ (difference 26 µg/m³, 95% CI 25 µg/m³ to 26 µg/m³).


Prison smoke-free policies achieve significant improvements in indoor air quality. A national smoke-free policy would therefore be an effective means of protecting prisoners and staff from harm due to SHS exposure in the prison environment.

Journal Article Type Article
Acceptance Date Mar 8, 2019
Online Publication Date Jun 14, 2019
Publication Date 2019-06
Deposit Date Apr 4, 2019
Publicly Available Date Jun 18, 2019
Journal BMJ Open
Electronic ISSN 2044-6055
Publisher BMJ Publishing Group
Peer Reviewed Peer Reviewed
Volume 9
Issue 6
Article Number e025782
Keywords General Medicine
Public URL
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