Do current levels of air pollution kill? The impact of air pollution on population mortality in England

The current air quality limit values for airborne pollutants in the UK are low by historical standards and are at levels that are believed not to harm health. We assess whether this view is correct. We examine the relationship between common sources of airborne pollution and population mortality for England. We use data at local authority level for 1998–2005 to examine whether current levels of airborne pollution, as measured by annual mean concentrations of carbon monoxide, nitrogen dioxide, particulate matter less than 10 µm in diameter (PM₁₀) and ozone, are associated with excess deaths. We examine all-cause mortality and deaths from specific cardiovascular and respiratory causes that are known to be exacerbated by air pollution. The panel nature of our data allows us to control for any unobserved time-invariant associations at local authority level between high levels of air pollution and poor population health and for common time trends. We estimate multi-pollutant models to allow for the fact that three of the pollutants are closely correlated. We find that higher levels of PM₁₀ and ozone are associated with higher mortality rates, and the effect sizes are considerably larger than previously estimated from the primarily time series studies for England.