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

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