The findings discussed in this report persuade us that daily variations in concentrations of several air pollutants and long-term average concentrations of fine particles, sulphate particles and sulphur dioxide are associated with a range of effects on the cardiovascular system. Consideration of the accepted features of causal associations leads us to think that many of the associations are likely to be causal. Furthermore, we think that the impacts on public health implied by these associations, though not as large as those arising from factors such as family history, active smoking and hypertension, are important and that a precautionary approach should be adopted in future planning and policy development.
We see no reason to conclude that the effects described above, especially those relating to day-to-day changes in concentrations of air pollutants, are unlikely to be occurring, now, in the UK. On the contrary, though studies undertaken in the UK are few they lend support to these conclusions.
It is clear that much remains to be discovered and explained regarding the association between exposure to air pollutants and cardiovascular disease. One aspect that is intriguing is the clear heterogeneity that exists in results obtained for some pollutants between different geographical locations. Though this is at present not well understood we feel that it offers scope for further study that may well be valuable.
COMEAP will soon be undertaking a revision of its earlier work on quantification of the effects of air pollutants in the UK. The findings from this report support the need for further analyses of the quantitative effects of air pollutants on hospital admissions for treatment of cardiovascular diseases, of deaths from cardiovascular causes and of reductions in life expectancy. We make no recommendations as to which specific coefficients linking measures of pollutants and effects should be used for this work but draw attention to the likely value of the original meta-analytical work included in this report.