Air Quality Project – summary final presentations


The Liverpool Friends of the Earth Air Quality project finished May 2017. The final presentations are available in the links below.

It is very important to stress that this data must be treated with caution. To put it simply: it is not possible to say that a single air quality reading on a particular day means that air quality is poor for that area. This issue is much more complex than that.

Thanks again to the members of Breathe Easy, other volunteers and the Liverpool CCG who helped during the project.

Liverpool FoE – Final Presentation_Final Version

Liverpool FoE – Air quality Survey Summary

Air Quality Project update


Our citizen science air quality project is now drawing to a close…the primary survey is now ended…we have sent out the follow-up survey to the primary survey respondents… data is being analysed …and the evaluation report prepared in order to hand to the Liverpool CCG shortly

So…our results and conclusions from our project will be posted here shortly!

Thank you again so much to our funders, the Liverpool CCG, all our volunteers who have carried our pollution sensors around and all those who have completed our air quality survey(s).

Please watch this space!

In the meantime: here is a copy of a talk about our project given at Ignite Liverpool last February and an infographic produced from our project

Citizen Science Air Quality: Project Introduction & Survey


Citizen Science Air Quality Project:  Air pollutants and healthier travel choices

Survey now live – available here!

Air quality is a national and global issue with significant costs upon the UK – estimated by the Government at £8.5-20bn per annum health impacts (Defra, 2010: This is twice the costs of physical inactivity and comparable to the cost of alcohol misuse to society (Environmental Audit Committee, 9th Report – Air Quality: a follow-up – Volume I, 14 November 2011). There is increasing national interest and recently Client Earth won a case against UK Government (

The whole of the city of Liverpool is declared an Air Quality Management Area for Nitrogen Dioxide (NO2) by Liverpool City Council (see: Air pollution is a contributory factor towards respiratory illness and related conditions, and directly affects health. An estimation of 239 deaths in Liverpool in 2010 were attributed to illnesses associated with air pollution (Public Health England 2014 ‘Estimating local mortality burdens associated with particulate air pollution’).

Liverpool Friends of the Earth are launching a Citizen Science project to investigate air quality awareness and perceptions within Liverpool and to investigate the question:

Can transparency of air quality data through citizen science increase awareness and empower people to make healthier travel decisions through reducing their exposure to air pollutants?

The project has been kindly funded by the Liverpool Clinical Commissioning Group and is run by Michael King and Stella Shackel. The funding has enabled 4 portable sensors to be purchased. These sensors can measure the air pollutants: particulate matter, Carbon Monoxide and Nitrogen dioxide. Data from these sensors can be overlaid on Liverpool maps to show the pollution levels for the routes along which the sensors are carried. More information is at:

Volunteers will be engaged in the data gathering and feedback processes to help understand how Citizen Science approaches can help individuals and community groups. The data generated could also be used in the future for other purposes, such as comparing air quality data with the presence of green infrastructure. Friends of the Earth also has a national air quality campaign:

This project is about investigating low-cost methods to empower citizens with information to help them understand air quality levels and decide for themselves how they might act. The air quality data collected will be made available on the Liverpool FoE website.

Please answer our online survey to assess air quality awareness and help to promote it by re-tweeting our tweets from our twitter @LiverpoolFoE. Please answer the survey if you can and contribute to our evidence base! Thank you!

Air Quality in Liverpool


We are looking at air quality within Liverpool as part of our local efforts.

We are currently running a “citizen science” project. To do this we are grateful for funding from the Liverpool Clinical Commissioning Group.

This is a small-scale project with some simple objectives:

  1. We want to understand more about the different technologies that can be used to support citizen science initiatives around air quality
  2. We want to understand how these technologies, and the data they generate, can be used to help individuals and community groups.

No doubt there will be other learning along the way. For example, we are interested in how this sort of community-level engagement and “hyperlocal” data gathering can be used to supplement and complement city-level and national air quality monitoring and management.

3rd Annual Gary Mahoney Memorial Debate: How Green Can We Go?

How Green Can We Go?

Merseyside Environmental Trust & Liverpool Friends of the Earth

Invite you to the

3rd Annual Gary Mahoney Memorial Debate

Thursday 1st June – 7.30pm

Pearce Room, Adelphi Hotel, L3 5UL



Clara Paillard (PCS Union)

David Connor (Green Entrepreneur)

‘Green Drinks’ @ WAVE Bar – 6.00pm

networking downstairs below the Adelphi

FOE 2017 Poster (1)

Mapping the data (2)

Following on from a previous post we have been grateful for the help of volunteers from the Breathe Easy Liverpool North group.

This post gives some further examples of the data gathered from our volunteers. The previous post showed some NO2 data captured by the Air Quality Egg sensors.

This post will share some example PM 2.5 data captured using the AirBeam sensors – more info on these sensors is available in previous posts.

The map below shows pm 2.5 readings for 26 Feb 2017 pm. Key roads are highlighted. The readings are generally green and good.

Below is the time-series equivalent of this data showing the data was captured between 16:28 and 17:09. The rise in the levels at the end of the chart may or may not be the result of higher traffic levels as peak hour begins. As always with this sort of data a lot of caution should be exercised before drawing conclusions or insights too quickly.

The map below is also for 26 February but this time during the morning. This time from 11:52 to 13:30. Again the readings are generally green.

There are a batch of readings coloured yellow which appear to be actually located in a large retail store. This can reflect internal local effects, such as a cafe or restaurant with gas burners for cooking. Again, interpretation of this data on its own should always be treated with caution.

The final mapping shared here is from 27 February 2017. All of these readings (more than 5,000) are green and show low levels of PM2.5.

This project is about trying to understand how this sort of data and technology can help. We will post further here on the lessons learnt from discussion with our friends at Breathe Easy and elsewhere.

Mapping the data (1)

The technical testing of the sensors has completed and we are grateful to various technical volunteers who have carried the sensors and given us feedback. This project has moved into engaging with the final user group who were always the focus. The aim is to engage with people who might benefit most from this technology and we were very lucky to find the Breathe Easy Liverpool North group, who are a great bunch of people and have been very welcoming to our efforts. We are very grateful.

We first presented to this group on 18 November 2016 to explain the objectives of the project. The group doesn’t meet during the middle of Winter and so we arranged to come back to them in February when their meetings started up again. By February we would have finished our technical testing as per the plan and we would have sensors for them to use if they were willing.

One Friday 3 February 2017 we presented to the Breathe Easy North Liverpool group again and we were grateful that there were two volunteers willing to take 2 sensors: one AirBeam to measure particulate matter and one Air Quality Egg to measure NO2.

We had some technical problems with the AirBeam which meant we didn’t get any data in the first 2 weeks, but early tests on the data captured by the Air Quality Egg looked positive. The mapping of two trips are shown below to illustrate what this sort of technology can do.

The map below shows the data from the Air Quality Egg (Tweedledee) for 20 February 2017. We won’t name the volunteer who captured this data for data protection and privacy reasons, however we are grateful to their efforts.


This data can also be looked at as a time-series and this is shown below. The readings start at approximately 14:00 and finish approximately 15:00 on 20 February 2017.

The goal of this project is to share these findings with the group to get their feedback and see if this tallies with personal experiences and local knowledge. Do the sensor readings agree with personal views on areas of poor air quality? etc.

The second mapping is shown below for 22 February 2017 with the same sensor. This shows similar routes but also some new areas of the city explored. This mapping does show more red readings than the previous mapping. Also, Breck Road is green and has good air quality readings for both trips. Chavasse Park is green, as might be expected for a pedestrianised area – giving some more confidence in the sensor readings. Again, this will be explored further with the group to see if this matches with personal experiences.


As above this data can also be shown as a time-series as below. This shows the readings taken between approximately 13:30 and finish approximately 18:00.

We will analyse more data and share that shortly. More to come.

Note: all the data here should be treated with caution. These are spot measures with low-cost sensors and so they should not be used as a basis for assessing air quality across a longer duration or a wider area. 

The People’s vision for Liverpool City Region

As part of the UK devolution agreement, elections will be held for the Liverpool city region mayor (covering Liverpool, Wirral, Halton, Knowsley, St Helens and Sefton) on the 4th May 2017.
The ideas below were generated at a Transition Liverpool event in October 2016. Discussions explored the opportunities a devolved Liverpool City Region could bring. Click here to see the full notes.
This questionnaire has been put together by Liverpool Friends of the Earth, Transition Liverpool and Merseyside Environmental Trust based on the ideas from the Transition Liverpool event. We have come together to give you the opportunity to voice your opinions and ideas on key areas that you would like to see addressed by the Liverpool City Region Mayor.
We will compile your responses and raise the issues with the mayoral candidates.
Deadline date for completion: 15 March 2017

Citizen Science Air Quality – First tests with the Air Quality Eggs

In a previous post some early tests were performed on one of our two Air Quality Eggs. This post will continue that process but show the two of them together.

Here’s a picture of the two Liverpool FoE Air Quality Eggs (AQEs), which I’ve named Tweededee and Tweedledum!


In this mode they are static AQEs, connected to power, monitoring local air quality and reporting NO2, CO, temp and relative humidity to the opensensors data store every 4 seconds. Below is a picture of the pair of Eggs reporting their data taken 17 November 2016 at 15:32 GMT.


This picture shows one of the challenges of devices such as this. The two Eggs are next to each other but Tweedledee is reporting an NO2 figure of 44 ppb, whereas Tweedledum is reporting 63 ppb.

Investigating this further, the photo below includes another AQE that I have had for a year or so. Again it’s in the same location and picture was taken within minutes of the photo above.


Tweedledee now reads 52 ppb, Tweedledum 74 ppb (a similar delta), whereas the other AQE on the right gives a reading of 22 ppb. The temperature, Carbon Monoxide and Relative Humidity figures are all identical or very close. It’s the NO2 numbers that have some variation.

There are various technical answers to this variation in the data. The Eggs were calibrated before they were shipped, but it’s possible that they need re-calibration, which is not a simple process at all. The key lesson for this project is that individual points from these sort of sensors should be treated with caution.

Before moving on this can be investigated a bit further. Below is a chart that shows the temperature readings for Tweedledee and Tweedledum from 12 November 2016 to 14 November 2016. As above, the sensors are indoors and next to each other. The blue line is Tweedledee and the orange line Tweedledum.


The chart shows the temperature readings slightly differing, but they definitely move in step with each other. The correlation of these data sets is 97% for those who like those sort of statistics!

The final chart in this post is for the same 2 Eggs and the same time period, but this time the data is the NO2 readings from each Egg.


The top line is Tweedledum and the lower one Tweedledee. The chart shows that Tweedledum consistently reports higher than Tweedledee. The movement of the two data sets is harder to see, but they do appear to move in step. The correlation between the two data-sets is 69%. Detailed technical transformations to analyse this data further will not be performed beyond this. The key point from these tests is that the data is potentially valuable, but individual data points should be treated with caution.


Citizen Science Air Quality – early tests of the Air Quality Egg

A previous post has reported that we have recently received the 2 Air Quality Eggs that are part of the Liverpool Friends of the Earth Citizen Science Air Quality Project. I have used these Eggs before, but there are some new features with these devices, which are important for this project – specifically they offer:

  • GPS for location tracking and so we can go mobile with them; and
  • an onboard SD card for local data storage to complement the mobile data capture

After the unpacking the first stage in the project process is to test them and make sure they are going to be fit for purpose for our volunteers.

The initial set up connects to my WiFi and data is reported to openSensors. Without too many hiccups the Egg is reporting data. The validation of this is not pretty, but is a format like the screengrab below, which shows the Egg reporting Carbon Monoxide, Nitrogen Dioxide, Temperature and Humidity (just off-screen): opensensors

Once data is flowing it’s then useful to do some sense-checking on the data and also check the new features i.e. GPS and the onboard storage. So I took the Egg on a trip into Liverpool. During the journey, the Egg is powered by a battery and stores data on the SD card. This data was then later downloaded for analysis.

The picture below shows this data imported into QGIS – an open source GIS package – for analysis.


The GPS appears to be working fine. This was indeed the route taken, using a mix of bus and walking. You can see the larger spacing of the readings when the bus is moving at speed.

The colour coding used is just a spread of the data. Work to be done later is to determine the appropriate colour coding according to national guidance from health agencies and other expert bodies. For now, the colour coding simply shows the spread of data – with dark red being the highest values and white the lowest. The legend in the top right shows the schema and the associated numbers in parts per billion (ppb) of NO2. These figures should not be used in isolation. There’s always the possibility that an individual sensor is faulty or there is some other issue. Confidence comes with increased numbers of sensors and consistent readings over time.

One of the challenges that the test revealed is more about the physical side of the egg than the electronic and information side. We’re going to have to think about how someone can carry the egg, because it’s more bulky than the AirBeam PM sensor. We also need to make it a bit more weather proof and probably buy 2 portable batteries for our 2 sensors when they go mobile.

First tests are looking good though. Next is to get the other Egg up and running, do similar tests with it and then also do some comparison tests to see if these two eggs report similar data. I can compare these two to my other Air Quality Eggs that I’ve got from previous work over the last few years. More on this later.