1. Children and smokers in cars: Differences across two NZ city areas Oceania Conference - October 2011
Vimal Patel, George Thomson, Nick Wilson
Department of Public Health,
University of Otago, Wellington

2. Aims
To compare the point prevalence of smoking and SHS exposure in vehicles:
For areas: Between two areas of contrasting socioeconomic status in NZ
Over time: Between 2005 and 2011

3. Background: SES difference in SHS exposure in NZ cars
In 2010 NZ survey of yr students:
In four most deprived deciles 33% report exposure to SHS in cars
In two least deprived deciles 14% report exposure to SHS in cars
Most deprived 2.4 more exposed

4. Methods During Feb-April 2011 we observed in Wainuiomata and Karori
(high/low deprivation areas in Wellington, New Zealand)

5. Observation sites Wainuiomata Karori (low dep)
(Deciles 7-9: (Deciles 1-4:
30% smoking) 11% smoking)

6. What we observed Smoking in vehicles Whether the smokers were with:
others
children
(Later) Adults and children in all vehicles, to get vehicle occupancy rates per site

7. Results 149,886 vehicles were observed
Point prevalence of any smoking in cars:
3.9 times more in Wainuiomata (high dep area) .
For vehicles with children:
10.9 times greater in Wainuiomata

8. Children and smoking in cars in 2011 Karori vs. Wainuiomata
Conclusions
Observing smoking in vehicles provides an objective indicator of the different smoking behaviours, especially around children, within a society. This study further supports the evidence from New Zealand and internationally that those from high deprivation areas are much more likely to be exposed to SHS. If such people are being exposed to SHS in the confined space of vehicles, then it could be argued that home exposure is even more likely.
Increasing the prevalence of smokefree vehicles has a number of benefits. Besides reducing the SHS hazard to both non-smokers and smokers themselves (and probably the risk of vehicle crashes), smokefree vehicles help normalise smokefree behaviour.
The much higher exposure for those in more deprived areas in New Zealand, by observation, census, and survey data, with apparently widening disparities, indicates that the current educational approach is not particularly effective for protecting the more deprived from SHS in vehicles. While social marketing is highly desirable as part of an overall approach, the stronger signal about SHS hazards that legislation gives (along with the accompanying unpaid media publicity) may be the most effective and cost-effective way to markedly improve protection for the most deprived.

9. Car smoking changes:
39% reduction in the low dep area - Karori (2.0% to 1.2%)
24% reduction in the high dep area – Wainuiomata (6.4% to 4.9%)

10. Discussion
The SES gradients (3.9+ RR) were far greater than in survey (2.4 RR) and census (2.7 RR) data
Why?
Point prevalence v survey
One week recall problem for self-report survey?
Greater ‘normality’ affects survey report?

11. Why use car observations?
A way to measure ‘private’ smoking:
Vehicles are uniquely:
confined and ‘private’
observable from the outside
Helps triangulation of survey data

12. Policy implications
Large and widening socioeconomic gulf in exposure to SHS in vehicles:
Need for more effective tobacco control efforts for those in SES deprived areas
Need for greater protection of children in cars
Children are influenced by the extent and normality of smoking around them

13. Smokefree car laws
Support: In 2007–2008 survey of NZ smokers, 96% supported smokefree car regulation when young children were in the car (Thomson et al., (1285):139-40)
Precedent: At least 11 states/provinces in Australia, Canada, and USA have smokefree car laws to protect children
Effect: After 2007 South Australia smokefree law, survey increase in smokefree cars with children:
69% in 2005 to 82% in (Hickling, Miller, & Hosking, Oceania Tobacco
Control Conference. 2009: Darwin)

14. Acknowledgements Cancer Society of New Zealand for funding
The other observers: Catherine Jones, Losa Moata’ane, and Priyesh Patel
Dr James Stanley who provided statistical advice and support
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