Trends in urban air pollution in the United Kingdom during recent decades

Analyses of measurements and modelling studies show that SO₂ concentrations in most United Kingdom cities have decreased dramatically over the last 40 years. As a result, current concentrations do not provide an adequate picture of cumulative exposure of the built environment. Data for Lincoln Cathedral show that the current rate of exposure is about two-fifths of the average over the last four decades and that over the same period urban exposure was twice that in the surrounding countryside. Today, urban and rural exposures are similar. In contrast, urban NO_x concentrations have not declined, decreases in industrial emissions being approximately offset by increases in emissions from motor vehicles.