Applying pollution control measures to nitrogen oxide emissions

UK emissions of nitrogen oxides fell to 2.1 million tonnes in 1996, a decrease of nearly 4 per cent from the 1995 figure, and a fall of 26 per cent from the peak of 2.8 million tonnes in 1989. Emissions from road traffic accounted for 47 per cent of total emissions in 1996 but have fallen steadily since 1989 mainly as a result of the introduction of catalytic converters in cars. Exceedance of the UK standard for nitrogen dioxide, of 150 ppb measured as hourly concentrations, were recorded at 5 out of 52 sites in 1996.