The impact of smoke-free legislation on indoor air quality in bars in ...

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3. Impact on Particulate Matter2.5 3.1 Introduction In this section the results <strong>of</strong> the pre- and post <strong>legislation</strong> (three month and 12 month) PM2.5 measurements are presented. A total <strong>of</strong> 76 bars were sampled across four locations at phase 1 and 2 and a total <strong>of</strong> 59 bars sampled at phase 3. Analysis was carried out using paired analysis techniques to examine differences between the pre-<strong>legislation</strong> and three month post <strong>legislation</strong> stages and again between the pre <strong>legislation</strong> and 12 month post <strong>legislation</strong> stages. 3.2 PM2.5 concentrations Figure 3.1 shows PM2.5 concentrations before, three months after, and 12 months after the introduction <strong>of</strong> the smoking <strong>legislation</strong>. Before the <strong>legislation</strong>, 97% <strong>of</strong> bars had PM2.5 concentrations above 50 μg/m 3 with 88% having concentrations above 100 μg/m 3 . No bar had concentrations less than 25 μg/m 3 . Three months after the <strong>legislation</strong>, 72% <strong>of</strong> bars had PM2.5 concentrations <strong>of</strong> 25μg/m 3 or less with 1% <strong>of</strong> bars having a concentration greater than 100 μg/m 3 . Twelve months after the <strong>legislation</strong>, 72% <strong>of</strong> bars had PM2.5 concentrations <strong>of</strong> 25μg/m 3 or less with 3% <strong>of</strong> bars having a concentration greater than 100 μg/m 3 . Prior to the introduction <strong>of</strong> <strong>legislation</strong> 17% <strong>of</strong> bars had PM2.5 concentration over 500ug/m 3 but post <strong>legislation</strong> no bar had concentrations above 500 μg/m 3 (at three or at 12 months after the <strong>legislation</strong>). Figure 3.1: PM2.5 concentrations before and after the smoking <strong>legislation</strong> 60% 40% Percent 80% 20% 0% 0% 30% 20% Up to 10 0% 24% 20% 11-15 0% 18% 16-25 32% 3% 24% 26-50 14% 9% 3% 51-100 10% 71% PM 2.5 concentation ug/m3 1% 3% 101-500 Before <strong>legislation</strong> 3 months after <strong>legislation</strong> 12 months after <strong>legislation</strong> 14% 0% 0% 501-1000 3% 0% 0% Over 1000 10
Overall, mean PM2.5 concentrations reduced significantly from 344.37 μg/m 3 (median = 275.84, SD = 260.01) pre–<strong>legislation</strong> to 22.27 three months (median= 14.27, SD = 34.48) and 30.60 12 months after the introduction <strong>of</strong> <strong>legislation</strong> (median= 17.07, SD = 45.05). This represents a 94% reduction in mean PM2.5 concentrations after three months (paired T test, p = 0.000) and a 91% reduction in mean PM2.5 concentrations after 12 months compared to pre –<strong>legislation</strong> data (paired T test, p = 0.000). <strong>The</strong>re were no significant differences in mean PM2.5 concentrations at three months and at 12 months after the <strong>legislation</strong> (paired T test, p = 0.291). <strong>The</strong> percentage decrease in PM2.5 concentrations is shown in figure 3.2. Three months after the introduction <strong>of</strong> <strong>smoke</strong> <strong>free</strong> <strong>legislation</strong> almost three quarters <strong>of</strong> bars (74%) experienced over a 90% decrease in PM2.5 concentrations, with decreases <strong>of</strong> less than 80% only experienced in 8% <strong>of</strong> bars. Likewise 12 months after the <strong>legislation</strong>, over three quarters <strong>of</strong> bars (77%) experienced over a 90% decrease in PM2.5 concentrations, with decreases <strong>of</strong> less than 80% only experienced in 4% <strong>of</strong> bars. Figure 3.2: Percentage decrease in PM2.5 concentrations after the smoking <strong>legislation</strong> 40% 30% Percent 50% 20% 10% 0% 4% 0% Up to 30% 4% 31-80% 4% 81-90% 91-95% Percentage decrease in PM 2.5 concentration ug/m3 96-99% Concentrations in the control premises, which were assessed to account for seasonal factors, varied from 4.5 μg/m 3 (<strong>of</strong>fice) to 19.0 μg/m 3 (supermarket café) post <strong>legislation</strong>. Control samples provided a mean PM2.5 concentration <strong>of</strong> 7.4 μg/m 3 . 18% 19% 38% 43% 3 months after <strong>legislation</strong> 12 months after <strong>legislation</strong> 36% 34% 11
Page 1 and 2: The impact
Page 3 and 4: Contents Page Executive Summary ...
Page 5 and 6: 1. A programme of
Page 7 and 8: 1.2. Aims and objectives Th
Page 9 and 10: 2.3 Measurements PM2.5 was selected
Page 11: Figure 2.2: Passive sampler used to
Page 15 and 16: 4. Impact on Air Nicotine 4.1 Intro
Page 17 and 18: 5. Survey of bar s
Page 19 and 20: Figure 5.2: Impact of</stro
Page 21 and 22: 6. Discussion 6.1 Introduction This
Page 23 and 24: Table 6.2: Comparison of</s
Page 25 and 26: notes that in the US, there are jur
Page 27 and 28: 8. References Allwright S, Paul G,
Page 29 and 30: Control 17:159-165. Available from
Page 31 and 32: World Health Organization, 2005, Pa
Page 33 and 34: Name: Premises: ABOUT YOU 1. Have y
Page 35 and 36: If yes, what are these views? Posit

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