The first assessments of air quality changes at a shale gas site in the UK have been made by a team of scientists from the National Centre for Atmospheric Science, Universities of York and Manchester, and the British Geological Survey.

Scientists measured air quality before, during and after preparations for fracking at a shale gas exploration site near Kirby Misperton in North Yorkshire. The study took place over a two-and-a-half year period so that researchers could establish typical nitric oxide, nitrogen dioxide, ozone and airborne particulate matter levels for each meteorological season before shale gas extraction activities started.

The work is part of an independent baseline monitoring programme supported by Department of Business, Energy and Industrial Strategy (BEIS). As well as monitoring air quality, the study involves monitoring seismicity, water quality, greenhouse gases, ground motion and radon emissions.

The study found that both nitric oxide and nitrogen dioxide, two key air pollutants, increased at the site during the pre-operational phase. This was a twenty-week period of intense activity to prepare the site for fracking, and included a large number of lorry movements needed to supply and maintain equipment, plus diesel generators and compressors.

Nitric oxide increased three-fold during the pre-operational phase. Nitrogen dioxide also increased during the same period, although the concentration did not exceed any air quality limits. Researchers have attributed the increases to lorries and operations on site. Emissions from vehicles associated with protesters, the police and the media, plus wood fires at nearby protest camps, were also thought to be sources of pollution. Ally Lewis, NCAS Director of Science and Professor of Atmospheric Chemistry at the University of York, explains:

The largest, most visible detectable impacts above the surface are on nitrogen oxides (NOx), from the use of compressors, generators and additional vehicle movements. And, in this rather unique case, also from other vehicles associated with police, media and protest activities.

The overall air pollution emissions at the site, while it was prepared for fracking, were thought to be broadly similar in nature to the impacts that might arise from a single supermarket. Importantly however, the concentrations observed did not breach regulatory limits.

Kirby Misperton is one of the first sites to apply for a permit to carry out fracking in the UK. As such, it has been subject to extensive regulatory and public scrutiny, and the focus of a major programme of long-term environmental monitoring. Air quality researchers, led by Dr. Ruth Purvis, started monitoring air quality at Kirby Misperton in 2016.

This study is the first observational assessment of the incremental air quality impacts of operations at a shale gas site in the UK. It shows the importance of establishing a pre-fracking baseline beforehand so that the impact of new activities in the area can be assessed. For air quality this time period needs to at least one year due to weather variability.”

The well site did not proceed to hydraulic fracturing and equipment was removed from the site but licenses still remain in place; all monitoring remains in place should any activities occur in the future.


Study: Ruth M. Purvis, Alastair C. Lewis, James R. Hopkins, Shona E. Wilde, Rachel E. Dunmore, Grant Allen, Joseph Pitt, Robert S. Ward (2019): Effects of ‘pre-fracking’ operations on ambient air quality at a shale gas exploration site in rural North Yorkshire, England. Science of The Total Environment, Volume 673, Pages 445-454. []

Related NCAS news: Air pollution at gas well site rises despite lack of fracking

More information on the Environmental Baseline Monitoring

More information about the ongoing research on air pollution levels at Kirby Misperton, the Third Energy shale gas exploration site

Professor Ally Lewis recently gave evidence at a Science Media Centre briefing event titled ‘Fracking in the UK - what does the evidence say?’ and has been quoted by The Guardian and BBC.