Pollution research

Pollution research

The Tower of London from South of the river

Sniffing out pollution at the Tower of London

Our research question:
How can we measure and control pollution levels inside the Tower’s buildings? Can we find out if pollution is a problem for our collections?

Research project profile


The Tower of London, located in the middle of the City, is exposed to vehicle emission and industrial pollution from London and beyond. How much of that pollution gets inside the building and what effect might this have? Could pollution cause damage to the important artefacts on display?


In 2009 we carried out a collaborative project, funded by the European Commission, which measured the pollutant levels inside the Tower of London.

The project developed new ways to manage the impact of pollution on artefacts in our care, using a preventive conservation strategy. We harnessed new technology to measure pollution levels so that when they get too high, we can take action before any damage is caused to the objects.

Getting results

Though the project has finished, we are continuing to use the technology to monitor pollution levels at the Tower of London to make sure that our showcases are performing to the highest standards to protect the valuable objects within.

More conservation science research

More background

The project study showed that levels of sulphur dioxide (SO2) and ozone (O3) inside the Tower of London are very low. But, the levels of nitrous oxides (NOx), which are produced by vehicle exhausts, can become quite high throughout the year.

Nitrous oxides can damage organic material such as paper and silk. So some of our most fragile objects are placed inside showcases to protect and keep them safe for our visitors, now and in the future.

Learn about conservation

'Caring for the palaces' articles:

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