Does deprivation index modify the acute effect of black smoke on cardiorespiratory mortality?
- 1Occupational and Environmental Health Research Group, Faculty of Medical and Human Sciences, The University of Manchester, Oxford Road, Manchester, UK
- 2Biostatistics Group, Health Methodology Research Group, Division of Epidemiology and Health Sciences, Faculty of Medical and Human Sciences, The University of Manchester, Oxford Road, Manchester, UK
- 3Department of Civil Engineering, John Anderson Building, University of Strathclyde, Glasgow, UK
- 4Public Health Sciences Section, University of Edinburgh, Edinburgh, UK
- 5Emmes Corporation, Rockville, Maryland, USA
- 6Information and Services Division, NHS National Services Scotland, Gyle Square, Edinburgh, UK
- 7Occupational and Environmental Health Research Group, Faculty of Medical and Human Sciences, The University of Manchester, Oxford Road, Manchester, UK
- Correspondence to Melanie Carder, Occupational and Environmental Health Research Group, Faculty of Medical and Human Sciences, The University of Manchester, Oxford Road, Manchester M13 9PL, UK; melanie.carder{at}manchester.ac.uk
- Accepted 7 April 2009
- Published Online First 22 September 2009
Abstract
Objectives To investigate whether deprivation index modifies the acute effect of black smoke on cardiorespiratory mortality.
Methods Generalised linear Poisson regression models were used to investigate whether deprivation index (as measured by the Carstairs deprivation index) modified the acute effect of black smoke on mortality in two largest Scottish cities (Glasgow and Edinburgh) between January 1981 and December 2001. Lag periods of up to 1 month were assumed for the effects of black smoke.
Results Deprivation index significantly modified the effect of black smoke on mortality, with black smoke effects generally increasing as level of deprivation increased. The interaction coefficient from a parametric model assuming a linear interaction between black smoke (μg/m−3) and deprivation in their effect on mortality—equivalent to a test of ‘linear trend’ across Carstairs categories—was significant for all mortality outcomes. In a model where black smoke effects were estimated independently for each deprivation category, the estimated increase in respiratory mortality over the ensuing 1-month period associated with a 10 μg/m3 increase in the mean black smoke concentration was 8.0% (95% CI 5.1 to 10.9) for subjects residing in the ‘most’ deprived category (Carstairs category 7) compared to 3.7% (95% CI −0.7 to 8.4) for subjects residing in the ‘least’ deprived category (Carstairs category 1).
Conclusions The results suggest a stronger effect of black smoke on mortality among people living in more deprived areas. The effect was greatest for respiratory mortality, although significant trends were also seen for other groups. If corroborated, these findings could have important public health implications.
Footnotes
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Funding Medical Research Council, London, UK.
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Competing interests None declared.
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Provenance and peer review Not commissioned; externally peer reviewed.
