Camden Air Quality Monitoring

This interactive page provides information about Camden’s air quality monitors, enabling you to view their locations and the data they collect.

Improving air quality is a key priority for Camden, and we will use all resources at our disposal to play our part in achieving this. You can read more about what we are doing to reduce air pollution and how you can help on our air quality web pages.


Air pollution can harm everyone's health, at any stage in our lives. It is known to affect our lungs, hearts and brains, and is linked to many illnesses which can have a long-term effect on our health. Children, older people, and those with existing health conditions are most vulnerable.
When we talk about air pollution in London we are referring to the following two pollutants:
  • nitrogen dioxide (NO2) - an invisible gas produced by burning fossil fuels and other materials, for example in vehicle engines and gas boilers
  • particulate matter - often referred to as PM10 or 'coarse particulate matter' and PM2.5 or 'fine particulate matter', these are small airborne particles including dust, soot, and droplets of liquid. PM is produced when fuels and materials are burned, but also by friction and abrasion of surfaces and by chemical reactions in the air

Sources of air pollution in Camden

Sources of NOx (NO2 + NO) in Camden (LAEI 2016)

Sources of PM2.5 in Camden (LAEI 2016)

Monitoring air quality: methods and data

'Air quality' is effectively the healthiness of the air we breathe, and is measured by recording the amount of NO2 and particulate matter present in the air.
Monitoring air quality is important because it helps understand how air pollution is distributed throughout Camden, and allows us to measure the impacts of actions we take to improve air quality. We monitor air pollution levels at many sites across Camden, and we choose sites which are representative of public exposure to air pollution
Air pollution levels are monitored using a number of different instruments. Some of these are very basic pieces of equipment, while others use complex technology. Data from the monitoring stations are collected and uploaded online hourly, daily and monthly depending on the type of system.
All of the data that we record for long-term air quality monitoring can be viewed in our Annual Status Reports (ASRs). Our Annual Status Report for 2019 was published in July 2020 and presents the data we collected in 2019 as well as our progress delivering on Camden's Clean Air Action Plan 2019-2022. The next ASR will be published in July 2021.
Automatic monitoring stations
Camden Council has five automatic monitoring stations located across the borough. These are permanent installations which contain sophisticated electronic instruments to measure a variety of pollutants, including NO2 and particulate matter. Data is transmitted every 15 minutes to a central management system which is then automatically uploaded to Air Quality in England, where you can find data for all Camden's monitoring stations, create graphs and download raw data.  The Council's monitoring network is maintained by Ricardo Energy & Environment. Midtown business improvement district also owns and operates a site of its own, located in Holborn.
To view a graph of the pollutant levels over the past seven days for each site, please click on the location links below.
Automatic monitoring station data: long-term trends in air quality
The graphs below show annual mean concentrations of NO2, PM10 and PM2.5 measured by the five automatic air quality monitoring stations in Camden, from 2014 until the most recent year for which full ratified data is available.
Diffusion tube monitors
Diffusion tubes monitor long-term trends of NO2 concentrations and we have 19 sites located across Camden which we use for statutory annual air quality reporting. The tubes are typically mounted on lampposts or buildings and are collected every four weeks and sent to a laboratory for analysis, and the data is then uploaded to this website. Although the tubes cannot be used to provide up-to-the-minute pollution levels, they are easy to use and provide helpful complementary background data to the automatic monitors. 
In addition to the 19 monitoring sites that we use for statutory annual reporting, we also have 128 diffusion tube sites which are used for air quality monitoring for transport projects.
The charts below display monthly data for each year measured since 2015 for the 19 sites used for statutory annual reporting, as well as 13 sites which form part of the air quality monitoring for the Camden Town Low Emission Neighbourhood (LEN).
Please note each month is numbered to ensure the graph generates in the correct date order. Occasionally results can be compromised due to foreign objects or water droplets in the tube. The methodology recommended in the London Local Air Quality Management Technical Guidance has been applied to fill in any missing data from 2017 onwards, in order to ensure full data coverage.
A note on using diffusion tube data
Individual month-average NO2 concentrations should not be compared directly: a variety of local and environmental factors influence pollutant concentrations and it is advisable to consider the annual mean NO2 concentration which is calculated after taking into account any necessary seasonal or analytical adjustment factors. Month-average NO2 concentration instead provides an indication of seasonal changes.
Please also note that diffusion tube data will not be available for up to three months after the monitoring period due to the duration of the analytical process.

Long-term diffusion tube data: Annual mean NO2 levels by location (sites selected where there is complete data)
2020 - Monthly NO2 levels by location (March-May data is missing due to the COVID-19 lockdown)
2019 - Monthly NO2 levels by location
2018 - Monthly NO2 levels by location
2017 - Monthly NO2 levels by location
2016 - Monthly NO2 levels by location
2015 - Monthly NO2 levels by location
Community air quality monitoring
Camden’s air quality monitors are located in specific areas across the borough, however we cannot monitor at all locations. To increase data coverage we can support residents and community groups with undertaking diffusion tube monitoring projects in their own neighbourhoods, by providing training, guidance on obtaining and installing equipment, and by analysing data.
To get in touch about a possible community air quality monitoring project, please contact

AQ Mesh monitors
AQ Mesh monitors are small portable units that measure concentrations of NO2, PM10 and PM2.5 in the air. We occasionally use these sensors to monitor specific projects at key locations across the borough.
Data is transmitted every hour from the AQ Mesh units directly to a central hub, which is then uploaded on this website every 24 hours.
The graph below shows hourly average NO2 levels over the past seven days for each active AQ Mesh sensor.  You can also view, explore and download the information for this graph on the background data page.

NO2 measurements by site location (last 7 days)
AQ Mesh monitors are not certified as 'reference equivalent' analysers, and the data must therefore be considered as suggestive rather than providing a precise measure of pollutant concentrations.


The below map outlines the approximate locations of the 19 statutory diffusion tubes, 13 Camden Town LEN diffusion tubes, five automatic monitoring stations and six AQ Mesh monitors across Camden, which can be zoomed in and out using the tool on the left.

External monitoring data

High Speed 2 Ltd (HS2) is monitoring baseline air quality levels at a number of sites around Camden. You can view this data by clicking the links provided at the bottom of the following page:
You can learn more about our assurances with HS2 and how we are working to minimise and mitigate as far as possible the adverse impacts of the scheme on Camden.
Breathe London is a collaborative London-wide project to use real-time sensors in building a more detailed picture of air quality throughout London. The GLA, Environmental Defense Fund Europe and Air Monitors have worked with Camden and the other boroughs to install an additional 100 AQ Mesh monitors which will be used to assess pollution hotspots and to analyse the impact of traffic, weather and other conditions on pollution levels.
You can find out more on the Breathe London website.

More information

For further information on Camden’s air quality programme, including what we are doing and how you can get involved, please click here.
To sign up for free air quality alerts and forecasts from airTEXT, please visit the sign-up page of the airTEXT website.