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Monitoring data

Automatic and Non-automatic data is available for download, use the links below and on the side navigation to find the data you're interested in.

If you're looking for estimates of emissions - the amount of pollution produced by a range of activities can be obtained from the National Atmospheric Emissions Inventory (NAEI) (new window).

Use the Glossary for helpful information to understand the technical language used across the website.

Latest Data Trends

The latest data trends are available for download:
» Report of latest data trends and information at Heathrow (PDF)

Automatic Monitoring

These monitoring sites measure hourly pollutant concentrations from a continuous stream of air pumped through the analysers. Data are collected each day by modem from data loggers storing the information at each individual site. The data go back as far as 1992 at some locations and latest data are published in near real-time.
» Download a summary of available automatic data (PDF)

» Download automatic data from the data selector

Diffusion Tube Monitoring

These monitoring locations measure less frequently - exposure of the tube is usually on a weekly or monthly basis. Samples are collected by chemical reaction on a filter or substrate within the tube and then sent off to a laboratory for analysis. Final pollutant concentrations are calculated from these results and the results can take several months to be published.

» Map showing locations of diffusion tube monitors - measurements of air quality around Heathrow are averaged over weekly, fortnightly or monthly periods. These are small low-cost samplers which can be distributed over a wide area.

» Download data from diffusion tube monitors and search data from diffusion tube monitors.