Air quality in smoking and nonsmoking homes: what do a million minutes of measurements tell us?

Transcription

1 Air quality in smoking and nonsmoking homes: what do a million minutes of measurements tell us? Sean Semple Scottish Centre for Indoor Air, Population Health Sciences, University of Aberdeen, UK sean.semple@abdn.ac.uk

2 Health effects of SHS on children Royal College of Physicians report March 2010 Wide range of fetal and childhood health problems 25 children per day admitted to hospital 800 children per day see a doctor as a result of SHS exposure related ill-health Children of non-smoking parents 70% less likely to become smokers than children of smoking parents Having a smoke-free home increases the likelihood of quitting Globally 40% of children are regularly exposed to SHS at home Best current estimate for Scotland 12% of children regularly exposed to SHS at home That s 100,000 children - equivalent to Celtic Park and Ibrox stadium filled with children SHS at home is still a big problem in Scotland

3 Second-hand smoke (SHS) in homes Variety of projects over past 5 years All baseline or pre-intervention data 203 smoking homes (1,007,723 minutes) 28 non-smoking homes (40,599 minutes) Is there a difference in air quality between smokefree and smoking homes? How long does SHS linger in household air? How does SHS compare to outdoor air pollution?

4 Measuring air quality in homes in Scotland NHS Highland & Islands: Smoking cessation advisers University of Aberdeen & NHS Grampian: IAPAH REFRESH Maternity services Pulmonary Rehab Occ Health NHS Lanarkshire: First Steps NHS Greater Glasgow & Clyde: Smoking cessation advisers FARE Greendykes Family Centre Local Champion

5 How do we measure SHS? Most SHS aerosol is smaller than 0.5 microns in size Invisible to human eye

6 PM 2.5 = Particulate less than 2.5 micrometers in size Small particles that are inhaled in to the deep areas of the lung Lots of epidemiological evidence that PM 2.5 air pollution is linked to respiratory and cardiovascular health effects WHO guidance value of 25 mg/m 3

7 Smoke Levels (microgram/m 3 ) 1200 Optical particle counters Sidepak Dylos Time

8 PM 2.5 a good indicator of SHS

9 PM 2.5 a good indicator of SHS Q: How many cigarettes did they smoke?

10 PM 2.5 a good indicator of SHS Q: How many cigarettes did they smoke? A: 16

11 Not all smoking homes are the same This graph shows average levels measured in 203 smoking homes in Scotland Data from all homes with >20h of measurement (median is 78h15m)

12 Not all smoking homes are the same About 1 in 4 homes have average levels higher than the average air pollution in Beijing (99 mg/m 3 ) Two-thirds have average levels measured above the WHO 25 mg/m 3 guidance limit WHO guidance 25 mg/m 3

13 Smoke-free homes are much lower Smoke-free homes 28 homes (in black) WHO guidance 25 mg/m 3

14 Fine particles x7 higher in smoking homes >1 million minutes worth of PM 2.5 measurements made in over 230 Scottish homes Median (IQR) PM 2.5 concentrations in smoke-free homes (n=28) is 5.6 (2-9) mg/m 3 Median PM 2.5 in smoking-permitted homes (n=203) is 38 (15-91) mg/m 3 62% of smoking homes have daily average concentrations that exceed the World Health Organisation PM hour guidance limit (25 mg/m 3 ) 83% exceed WHO annual guidance of 10 mg/m 3 WHO guidance 25 mg/m 3

15 How long does SHS remain in the air? Analysed data from 103 homes Identified last cigarette of the day (9.30pm-3am) Time from peak (>25 mg/m 3 ) to 50% of peak (n=130) Time from peak to WHO guidance level of 25 mg/m 3 (n=115) Last cigarette of day

16 Almost an hour for SHS to reduce by 50%

17 2h 40m to reduce to WHO guidance About 1 in 4 cases it took more than five hours to reduce to WHO guidance limit

18 SHS remains in the air for many hours First and largest real-world (i.e. not artificial laboratory measurements) measurements of this type Huge variability due to different types of houses, ventilation, window opening etc. Probably still some SHS even when you reach 25 micrograms/m 3 so values are under-estimates 1 in 4 homes >5 hours Scottish Government campaign

19 London smog April 2014

20 Killer smog March 2015 Daily Express 19 March 2015 So how bad was the killer smog? WHO 24h guidance WHO annual guidance High and certainly not good for you but peak 1-hour average in central London was about 85 mg/m 3 24h average was 72 mg/m 3 nearly 3x WHO guidance for daily average

21 Typical PM 2.5 exposure in central London... Most days in 2014 it was about µg/m 3 Some occasional values above 50 µg/m 3 About 1 in 4 smoking homes in Scotland have average levels >99 mg/m 3

22 Final thoughts We can learn a lot by measuring SHS lingers for several hours Smoking homes generally have PM levels that are about x7 those of smoke-free homes Two-thirds are higher than the WHO guidance levels About 1 in 4 of them are worse than Beijing pollution or Killer smog in central London But they aren t all the same About a third of smoking homes have pretty good air quality and are taking steps to keep SHS low How can we encourage the rest to improve? Is it acceptable to expose children to these SHS concentrations in their own home? Is education enough?

23 Acknowledgments IAPAH Funded by the Irish Environmental Protection Agency Carole Garden 1, Marie Coggins 3, Karen S Galea 2, Paul Whelan 3, Hilary Cowie 2, Jon G Ayres 4 & Fintan Hurley 2. REFRESH Funded by the Big Lottery Fund Inga Wilson 1, Lynsey Mills 1, Amanda Amos 5, Deborah Ritchie 5, April Shaw 6, Rachel O Donnell 6, John Watson 6, Stephen Turner 1 First Steps 2 Smoke-Free Funded by the CSO, Scotland Tracy Henderson 7, Lynn Adams 7, Susan Lyttle 7, Amanda Amos 5, Rachel O Donnell 6, Stephen Turner 1 & All the First Steps workers at NHS Lanarkshire 1 University of Aberdeen 2 Institute of Occupational Medicine 3 National University of Ireland, Galway 4 University of Birmingham. 5 University of Edinburgh 6 ASH Scotland 7 NHS Lanarkshire