Measuring and quantifying airborne pollutants

Dr Mathew R Heal’s research into how air pollution affects human health has informed policy to help reduce emissions and raised public awareness.

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Air pollution is the environmental factor with the greatest impact on human health in the EU. Particulate matter (PM2.5), ozone (O3) and nitrogen dioxide (NO2) are the most important contributors to poor air quality, with up to 30% of the EU urban population estimated to be exposed to pollutant levels greater than EU limit values.

Exposure to PM2.5 alone is estimated to reduce average life expectancy in the UK by six months, with estimated annual costs of between £9 billion and £20 billion.

Research into air pollution at the University of Edinburgh has contributed evidence to formulation of government policies and has informed UK national guidance and policy-evidence documents for the Department for Environment, Food and Rural Affairs (Defra), the Health Protection Agency and the Environment Agencies.

Research summary

For 20 years, Dr Mathew R Heal of the Edinburgh and St Andrews Research School of Chemistry (EaStCHEM) has been leading a programme of pollution research on all three of the most important air pollutants: NO2, PM2.5 and O3.

Measurement of ambient NO2 by passive diffusion tube is widely used in the UK as part of air quality assessments required by law.

After determining that the prescribed methods were subject to inaccuracies, Heal group researchers defined optimal methods for new more accurate and reliable measurements. Determinations of the carbon-14 radioisotope quantities in samples of PM2.5 showed that much less of the material derived from fossil fuel origins than was generally assumed.

The group also used atmospheric chemistry transport models to quantify the sensitivity of PM2.5 components to reductions in industrial and other emissions, in order to identify which measures could best protect the population from exposure.

Heal group research has also shown how atmospheric models can simulate current O3 concentrations with high spatial resolution and predict future O3 concentrations, as well as regional hospital admissions and deaths resulting from a range of future emissions and climate change scenarios.

Informing assessments of air quality and policy

Nitrogen dioxide
Dr Heal’s more accurate and reliable methods are now incorporated into protocols applied to measurements of NO2 for statutory air quality assessments in all urban areas in the UK, of which >139,000 are made annually, at a cost of £500,000.
Particulate matter
The Heal group’s surprising findings on the high levels of contemporary (rather than fossil) carbon in samples of PM2.5 have been important for informing the most effective PM2.5 reduction policy actions to protect the population.

Heal group research has contributed to awareness of relative impacts of policy actions to reduce emissions compared with climate change, to new public health recommendations to raise public awareness of the adverse health effects of surface O3, and to strengthening warning systems with targeted ozone alerts for high risk groups.

Relevant publications

Relevant research publications from the Heal group include:

Heal, M.R., O’Donoghue, M.A., Cape, J.N. (1999) Overestimation of urban nitrogen dioxide by passive diffusion tubes: a comparative exposure and model study. Atmospheric Environment, 33, 513-524. doi:10.1016/S1352-2310(98)00290-8

Heal, M.R., Naysmith, P., Cook, G.T., Xu, S., Raventos, D.T., Harrison, R.M. (2011) Application of 14C analyses to source apportionment of carbonaceous PM2.5 in the UK, Atmospheric Environment 45, 2341-2348. doi:10.1016/j.atmosenv.2011.02.029

Heal, M.R., Heaviside, C., Doherty, R.M., Vieno, M., Stevenson, D.S., Vardoulakis, S. (2013). Health burdens of surface ozone in the UK for a range of future scenarios. Environment International, 61, 36-44. doi:10.1016/j.envint.2013.09.010

Vieno, M., Heal, M.R., et al. (2014) The role of long-range transport and domestic emissions in determining atmospheric secondary inorganic particle concentrations across the UK. Atmospheric Chemistry and Physics, 14, 8435-8447. doi: 10.5194/acp-14-8435-2014

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