Author's response: Linking particulate matter and sulphur concentrations to air pollution annoyance: problems of measurement, scale and control
1Municipal Institute of Medical Research, Barcelona, Spain.
2Universitat Pompeu Fabra, Barcelona, Spain.
3University of Southern California, Los Angeles, USA.
*Corresponding author. Centre for Research in Environmental Epidemiology (CREAL), Municipal Institute of Medical Research, IMIM, Barcelona Research Park (Office 183.01A), C/Doctor Arguader, 80, 08003-Barcelona, Spain. E-mail: bjacquemin{at}imim.es
Accepted 13 June 2007
We thank Dr Brody and Dr Zahran for their useful comments on our paper.1 We would like to respond to some of their points.
We agree that the phrasing of the question on annoyance could be misleading. The frequency with which subjects open the windows may indeed influence their perceptions. However, the decision to open windows may also be influenced by noise, which is a strong correlate of traffic-related pollution. The ECRHS included the following question: ‘Do you sleep with the window open at night during winter?’, thus we decided to further investigate the issue. Answers to this question were not correlated with annoyance. In fact, the mean of annoyance was lower in subjects sleeping with the window open (1.76 vs 2.35) which is in line with the notion that reported annoyance due to air pollution may be correlated with, if not driven by, the perception of traffic noise around the home.
We also tested whether the associations between the adjusted centre-specific means of annoyance and the air pollution measurements were different among subjects sleeping with or without open windows. Figure 1 shows that among subjects who sleep with open windows the association with air pollutants is indeed better compared with those who do not. However, the association shown in Figure 1a is mainly driven by the cleanest centre, namely Reykjavik, where most of the subjects (>80%) sleep with open windows in winter; when data from Reykjavik are excluded, the two figures are more similar even if the association remains better—although poor—for the subjects sleeping with the window open in winter.
|
We also agree with the scale limitations raised by Brody and Zahran. As we mentioned in the conclusion of our article, an analysis assessing the association between annoyance and home-based measurements would have avoided these limitations. We are currently estimating home outdoor air quality for all participants and re-analysing the association with annoyance, as we do believe that subjects report environmental conditions around the residential location rather than the general background level of pollution, captured with our measurements of PM2.5 or its sulphur content. Preliminary analyses indicate poor correlations between annoyance and estimates of home outdoor air quality with substantial heterogeneity across cities. This needs further evaluation.
Regarding the choice of the pollutants, as stated in the Methods, PM2.5 and S were chosen because they represent regional ‘urban background’ air quality. While S may vary spatially in places with industrial activities, it is important to note that none of our monitors were located in industrial hot spots. Most of the air pollution comes from traffic and the figures were shown non-adjusted and adjusted by traffic intensity, showing no difference between them.
Finally, we also agree that more socio-psychological variables, such as political affiliation, general beliefs and social connectivity, may be important determinants of perceived annoyance, and, more generally, the perception of risks. Because the ECRHS was primarily planned to investigate the distribution and aetiology of asthma, we lack more detailed psychosocial assessments that would allow us to further elaborate on the various issues raised by Brody and Zahran. However, it is also important to note that even in social sciences, the predictability of environmental concern and or environmental willingness to act is still limited despite the adoption of elaborate methods and the inclusion of variables such as general beliefs or values.2,3
 |
References |
|---|
 Top References |
|---|
1 Jacquemin B, Sunyer J, Forsberg B, Götschi T, Bayer-Oglesby L, Ackermann-Liebrich U, de Marco R, Heinrich J, Jarvis D, Torén K, Künzli N. Annoyance due to air pollution in Europe. In: Int J Epidemiol (2007) doi: 10.1093/ije/dym042.
2 Dietz T, Stern PC, Guagnano GA. Social structural and social psychological bases of environmental concern. Environ Behav (1998) 30:450–71.[Abstract]
3 Olofsson A, Ohman S. General beliefs and environmental concern – transatlantic comparisons. Environ Behav (2006) 38:768–90.
CiteULike 
Connotea 
Del.icio.us What's this?
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||