CEH & IOM report finds reduced mortality rates due to UK air quality improvements in past 40 years

Policies to clean up air pollution in the UK over the past 40 years have led to significant reductions in human exposure to air pollution and associated mortality rates, a new study has found.

Over the last 40 years, a series of landmark policies focused on controlling air pollution have been introduced. The combination of these policies alongside public awareness campaigns were aimed at reducing mortality rates due to exposure to airborne pollutants. These included:

• The 1979 UN Convention on Long-Range Transboundary Air Pollution
• The UK Clean Air Act 1993
• The UK Environment Act 1995
• Several Air Quality Standards Regulations, plus a series of EU Directives relating to different pollutants.

Research led by the Centre for Ecology & Hydrology, in collaboration with the Institute of Occupational Medicine, University of Oxford, and University of Edinburgh, charted the levels of emissions of a variety of air pollutants in the UK between 1970 and 2010.  It found that over this time, total annual emissions of fine particulate matter (PM_2.5), nitrogen oxides (NO_x), sulphur dioxide (SO₂) and non-methane volatile organic compounds (NMVOC) in the UK all reduced substantially. However, emissions of ammonia (NH3), mainly originating from agriculture, have not been declining substantially and more recently showed signs of a slight increase.

Consequently, mortality effects due to exposure to air pollution have dropped by 44% and 56% for NO2 and PM2.5, respectively between 1970 and 2010. For O3, attributable respiratory mortality in 2010 was 17% higher than it was in 1970, despite a decline by 24% compared to 1990.

The study highlights that tackling air pollution in the UK has brought substantial public health benefits, but remains an ongoing challenge. Nitrogen dioxide concentrations are still often above legal limits in many urban areas and levels of ammonia emissions are increasing. Currently, around 5% of all deaths in the UK are attributed to air pollution.

Edward Carnell of the Centre for Ecology & Hydrology, lead author of the study, says: “Technology advances over the past 40 years, such as the three-way catalytic converter for cars and equipment to reduce sulphur and nitrogen dioxide emissions from large power plants have contributed to significant reductions in emission levels and therefore improved public health. However, it is legislation that has driven these technological improvements.

“Our results demonstrate the effectiveness of a series of policies at UK and European level since 1970 and this research supports policy-makers’ efforts to continue implementing much-needed measures to further improve air quality.”  

The study, funded by the Natural Environment Research Council (NERC), has been published in the journal Environmental Research Letters.

The completed report can be read here.