Guide to the ‘Clean Air in Cities’ app and widgets
Air pollution is the world’s largest environmental health risk, killing an estimated seven million people each year.
The Clean Air in Cities App and Widgets were created by Clean Air in London to highlight the health impact of long-term exposure to human-made particle air pollution which is HIGH for many people in cities.
We wanted to address the problem created by Defra and others misleading people by highlighting only ‘LOW air pollution’ based on ‘Daily ALERT bandings’ for about 330 of 365 days per year. Instead, the App and Widgets highlight the health impact of long-term exposure to human-made particle air pollution which is MODERATE or HIGH for many people in cities. See:
The Clean Air in Cities App and Widgets report the health impact of long-term exposure to dangerous airborne particles (PM2.5) for the population in local areas, regions and England as a whole i.e. annual mean. The App and Widgets estimate the number of deaths attributable to air pollution on a pro rata, calendar year-to-date, basis and the time to the next attributable death as well as displaying the percentage of total deaths attributable to air pollution. They do not estimate or display the actual deaths from air pollution or the risk for an individual. Users can also see estimates for total population-weighted exposure to annual average concentrations of PM2.5 in different local areas and/or regions relative to the World Health Organisation guideline and England as a whole.
The Clean Air in Cities App and Widgets are available for iPhones, iPads and Android devices and can be downloaded from the appropriate store:
Simon Birkett, Founder and Director of Clean Air in London, said:
“Air pollution is the world’s largest environmental health risk, killing an estimated seven million people each year.
“We therefore produced the Clean Air in Cities App and Widgets to highlight this risk and counter the impression created by successive governments that air pollution ‘LOW air pollution’ based on ‘Daily ALERT bandings’ for about 330 of 365 days per year. These daily alert levels were set to warn of health risks during major air pollution episodes not day to day exposure to air pollution.
“Instead, we highlight the health impact of long-term exposure to human-made particle air pollution (annual mean PM2.5) which is MODERATE or HIGH for many people in cities relative to the World Health Organisation guideline.
“Notifications from the App and Widgets keep us motivated to fight for clean air.
“We hope that other people will find the App and Widgets valuable and share their information widely.”
CAL 381 Guide to the CAIC App and Widgets 281120 V3
The sections below have 20 top tips for using the App and 12 for using the Widgets. The App and Widgets use and publish the same underlying data.
Top 20 tips for using the ‘Clean Air in Cities’ App
1. The App is available free for iPhone, iPad and Android devices and can be downloaded from the appropriate store:
2. The App was updated in 2021 for: the latest published data from Defra and Public Health England (2019); iOS 15 and Android 5 and up; bug fixes; performance enhancements; and the addition of news alerts. Don’t forget to check for app version 2.2 or later.
3. The Clean Air in Cities App was designed to address the misleading impression created by Defra and others highlighting only ‘LOW air pollution’ based on ‘Daily ALERT bandings’ for about 330 of 365 days per year. Instead, we highlight the health impact of long-term exposure to human-made particle air pollution which is MODERATE or HIGH for many people in cities. See:
4. The App reports the percentage and number of deaths attributable to human-made fine particle air pollution (PM2.5) so far this year. It also uses the Clean Air in Cities Index® (also known as the Birkett Index®) to show total PM2.5 levels relative to the World Health Organisation’s latest guideline for human exposure to PM2.5 (published on 22 September 2021). By selecting ‘Always’ under ‘Show Previews’ for the ‘Clean Air in Cities app’ in ‘Notifications’ on ioS devices the notifications will appear in full on the face of the device to save you looking for it.
5. The App lets you share news or the latest estimate of deaths attributable to fine particle air pollution so far this year for any local authority or region in England or England as a whole e.g. by Email, Facebook, LinkedIn, Messaging, Twitter and WhatsApp.
6. The ‘+ ALL REGIONS’ button lets you add the nine regions in England; ‘+ ALL LOCAL AREAS’ adds all 150 local areas in England; and ‘+ ALL REGIONAL AREAS’ adds all areas in a region. These can be reset in settings.
7. The ‘+’ sign lets you search manually for local areas and regions and add them. Or let location services find your local area and others within your region. Please note that the search box will not suggest areas if they have already been selected e.g. through batch loading.
8. The ‘Edit’ button in the App allows you to re-order areas. We like to list all regions and all local areas in our region (in alphabetical order). Tip 6 shows how to do it automatically!
9. Why not add the nine regions including yours and then all your region’s local areas?
- East Midlands
- East of England
- North East
- North West
- South East
- South West
- West Midlands
- Yorkshire and Humber
10. The App shows the percentage (%) of total deaths attributable to human-made particle air pollution (PM2.5) in every local authority and region in England.
11. The App shows population-weighted total concentrations of human-made fine particle air pollution (PM2.5) for any local area and region in England and England as a whole compared to the WHO guideline.
12. The App’s clock shows the proportion of time between deaths attributable to particle air pollution (PM2.5), actual time and flashes 15 seconds before the next statistical ‘death’.
13. The App could include Northern Ireland, Scotland and Wales (or other countries) if the relevant government would provide resources and the population-weighted PM2.5, attributable fraction and total deaths for it.
14. Ask politicians whether they use the App and know the latest estimate of deaths attributable to PM2.5 so far this year in their area
15. The ‘Website’, ‘News’ and ‘Settings’ buttons let you find out more about Clean Air in London’s work and the ‘Clean Air in Cities’ App. They include ‘Reset’ (or ‘Home’) and ‘Refresh’ buttons for their content.
16. The ‘News’ button lets you see selected ‘News alerts’ about air pollution episodes, blog posts and media stories posted by ‘Clean Air in London’. For examples, please see: https://cleanair.london/news-alerts/.
17. The App may send you useful notifications e.g. when the number of deaths attributable to particle air pollution in one of your areas reaches a significant milestone e.g. 5, 100 or 1,000 depending on the size of the area. It works best if you go to Settings -> Notifications -> Clean Air in Cities App -> ‘Banner style’ (persistent) and ‘Show previews’ (Always) for the App.
18. The App may send you occasional notifications (such as news or alerts about air pollution episodes) or links to new posts on Clean Air in London’s website.
19. The ‘Settings’ button lets you amend notifications, learn about the App, read our privacy statement and terms and conditions and reset all regions and areas.
20. Thank you for reading these tips. Please reply to one on Twitter with your own tips for improving our App or contact us at About https://cleanair.london/about/.
2. Top 12 tips for using the ‘Clean Air in Cities’ widgets
1. Two Clean Air in Cities Widgets, one small and one wide, are available for iphones, ipads [and android devices]. They display the most relevant and up-to-date air pollution data for any one local area, region or England as a whole on your home screen or notifications page. They mirror data in the App.
2. Before updating or loading your Clean Air in Cities App or Widgets, please allow Settings -> Privacy -> Location Services -> ‘On’. If the Clean Air in Cities app is already installed on your device, please Allow Location Access -> ‘While Using the App [or Widgets]’. This is necessary to install the Clean Air in Cities Widgets. You can edit or turn off this functionality later.
3. If ‘or Widgets’ does not appear in Location Access you will need to accept the pop-up ‘Allow widgets from ‘CleanAir‘ to use your location’ when installing the first Widget or allow ‘While Using the App or Widgets’ separately in Settings -> Privacy -> Location Services -> On -> Location Access after loading the Clean Air in Cities Widget.
4. Please update or install the Clean Air in Cities App Version 2.2 or later (same on App and Android). Please allow Settings -> Privacy -> Location Services -> On -> Location Access -> ‘While Using the App [or Widgets]’ if you have not already done so.
5. Two Clean Air in Cities Widgets are available for iphones. First, tap on the home screen or swipe left for the notification page. Second, tap the ‘+’ sign top left. Third, select the Clean Air in Cities (CleanAir) App which reveals the small widget immediately and offers the wide widget by swiping left. Fourth, ‘Add’ one or other widget. Fifth, repeat steps two to four to add more widgets for amending location later. Sixth, press ‘Done’ top right. Check that Settings -> Privacy -> Location Services -> ‘On’ -> Location Access is allowed ‘While Using the App or Widgets’ as above if the area does not appear within two or three minutes.
6. Two Clean Air in Cities widgets are available for ipads. First, swipe right on the main home screen to reach the notifications page. Second, tap the ‘+’ sign top left (i.e. short tap). Third, select the Clean Air in Cities (CleanAir) app which reveals the small widget immediately and offers the wide version by swiping left. Fourth, ‘Add’ one or other widget. Fifth, repeat steps two to four to add more widgets for amending location later. Sixth, press ‘Done’ top right. Check that Settings -> Privacy -> Location Services -> ‘On’ -> Location Access is allowed ‘While Using the App or Widgets’ as above if the area does not appear within two or three minutes.
7. We recommend installing two or three small Widgets and two or three wide Widgets – with one on your home screen and the others on another screen of your device. We use small and wide Widgets for Current Location, Our Local Area, London and England.
8. Tapping briefly on the installed Widget opens the Clean Air in Cities app i.e. the App not the Widget. To edit the Widget, first tap and hold the widget (i.e. long tap) to reveal a pop-up menu offering ‘Edit Widget’, ‘Edit Home Screen’ and ‘Remove Widget’. Second, select ‘Edit Widget’ to search and select your current location or any one local area, region or England as a whole for reporting in the widget. Third, select or change an existing area, by tapping on the named area (highlighted in blue) to reveal the search page and select your area. Fourth, tap the background of your device to confirm the new area i.e. the screen outside the Widget.
9. We recommend keeping a ‘Current location’ version of the Widget on the home screen of your device. This allows you to see local statistics as you travel around England. You can allow ‘Location access’: ‘While Using the App or Widgets’; ‘While using the App’; ‘Ask Next Time’; or ‘Never’. We do not track identifiable data on individuals. We also recommend keeping other versions of the Widget, small and/or wide versions for your local area, region and England as a whole on a separate page of your device or the notifications page. If Location Services is turned off, any Widgets using that functionality will show a stroke through the location pin (i.e. top left of the widget). The stroke will disappear when Location Services is turned on again.
10. Better still, ios devices let you create a ‘Stack’ on your homepage of several small Clean Air in Cities Widgets (or wide ones) and re-order them. This allows you to have (say) four Widgets on top of each other: 1. Current location; 2. Westminster; 3. London; and 4. England. You can reorder them in edit, scroll through them and have everything you need in the space of one small (or wide) Widget! Amazing.
11. Two Clean Air in Cities Widgets are available for Android phones and tablets in light and dark variants to suit your preference. First, touch and hold an empty space on your Home screen. Second, tap ‘Widgets’ on the popup menu that appears. Third, scroll down the list of available widgets to find ‘Clean Air in Cities (CleanAir)’ app. Fourth, tap and hold the widget variant you would like to add and then drag it onto the available space on your Home screen. Fifth, select your current location or any one local area, region or England as a whole from the list to be shown in the widget. If you selected current location, you will be prompted to grant location permission which is required for the widget to determine local area as you travel around England. Finally, repeat all the steps above to add more widgets to your Home screen.
12. There are now six Clean Air in Cities Widgets – two small, two wide and two tall with counters or news updates. Ideas welcomed!
3. Background to the Clean Air in Cities Index®
The World Health Organisation (WHO) has ‘guidelines’ for human exposure to different forms of air pollution. They chose deliberately not to call them standards, limits or recommendations because there is known ‘safe’ level for exposure to fine particle air pollution (PM2.5).
Further, while concentrations for short-term exposure to PM2.5 have been colour-coded in bands for many years, Clean Air in London was the first, to our knowledge, to propose a colour-coded banding for long-term exposure to PM2.5.
Clean Air in London will keep its colour bandings under review because scientists have confirmed health effects of air pollution at lower concentrations of PM2.5. This evidence may lead to the WHO reducing its guidelines when they are published in 2021.
The ‘Clean Air in Cities Index’ is also trademarked as the Birkett Index. This was done to maintain high standards for its use.
Clean Air in London®, Clean Air in Cities Index® and Birkett Index® are registered trademarks of Clean Air in London:
4. Clean Air in London articles about the health impacts of air pollution
For more details on the ‘Clean Air in Cities Index’ and the short and long-term health impacts of air pollution:
5. Background to the health impacts
Public Health England report titled ‘Estimating Local Mortality Burdens associated with Particulate Air Pollution’ (April 2014):
Defra publishes the anthropogenic (human-made), non-anthropogenic (e.g. volcanic dust and sea salt) and total population-weighted concentrations of PM2.5. Non-anthropogenic levels are the residual after Defra’s modelling has identified individual sources of PM2.5. In recent years for England, it has been:
0.45 ug/m3 in 2021 (of 7.35 ug/m3 total) -> Anthropogenic = 6.90 ug/m3
0.61 ug/m3 in 2020 (of 7.54 ug/m3 total) -> Anthropogenic = 6.93 ug/m3
0.53 ug/m3 in 2019 (of 9.57 ug/m3 total)
0.44 ug/m3 in 2018 (of 9.52 ug/m3 total)
0.51 ug/m3 in 2017 (of 9.41 ug/m3 total)
0.54 ug/m3 in 2016 (of 9.99 ug/m3 total)
1.12 ug/m3 in 2015 (of 9.42 ug/m3 total)
2.11 ug/m3 in 2014 (of 11.17 ug/m3 total)
2.13 ug/m3 in 2013 (of 11.52 ug/m3 total)
2.11 ug/m3 in 2012 (of 11.11 ug/m3 in total)
2.64 ug/m3 in 2011 (of 12.09 ug/m3 total)
* Micrograms per cubic metre (ug/m3)
6. Annual updates
Updates to the App and Widgets are usually released annually after Defra, Public Health England and the Office of National Statistics update their annual data. This new data includes:
1. Defra data for population-weighted annual mean PM2.5 (scroll down towards foot of webpage):
2. Public Health Indicator ‘D01 – Fraction of mortality attributable to particulate air pollution’:
The local area and regional data can be exported as a CSV file.
3. Office for National Statistics – Deaths registered by area of usual residence, UK:
4. Update the master table sorted in region and then alphabetical order.
5. Check the ‘About’ (e.g. new year e.g. 2021), ‘Terms and conditions’ and ‘Privacy’ pages.
6. Check links and webpages used by the App and Widgets and legalise e.g. Terms and conditions and Privacy.
7. Consider updating some health text e.g. latest London or national estimates of deaths. Explain emissions, concentrations, exposures, impacts and outcomes. Also rankings?
8. Update App link on Facebook.
9. Test the Apple and Android versions of the App and Widgets before release.
7. Update for 2021 data in 2023
The total annual mean concentration of PM2.5 in England was 7.35 ug/m3 in 2021 i.e. a small reduction from 7.54 ug/m3 in 2020. The equivalent anthropogenic numbers were 6.90 ug/m3 in 2021 and 6.93 ug/m3 in 2020 (see section 5 above). All other things being equal, a reduction in PM2.5 will lead to a reduction in deaths attributable to it.
The attributable fraction published by the Office for Health Improvements and Disparities is calculated by scaling the Concentration Response Function of 8% per 10 ug/m3 of (anthropogenic) PM2.5. Hence the small reduction in anthropogenic PM2.5 above resulted in a small reduction in the attributable fraction for England from 5.6% in 2020 to 5.5% in 2021. This uses the new COMEAP methodology introduced in January 2022 (see below) i.e. 8% instead of 6% per 10 ug/m3.
The Office for National Statistics reported 549,349 total deaths from all causes in England in 2021 (including all COVID-19 deaths). 63,555 deaths were ‘due to COVID-19’ compared to 69,299 deaths ‘due to COVID-19’ in 2020. The ONS also publishes a number of deaths ‘involving COVID-19’ which include those where COVID-19 appears anywhere on a death certificate.
CAL has deducted the number of deaths ‘due to COVID-19’ from each local area and region and England as whole to estimate an underlying total number of deaths (which was similar to previous years ex-COVID-19) of 485,794 deaths. This compares to 500,000 in 2020 and 496,370 in 2019.
With PM2.5 concentrations and therefore the attributable fraction slightly lower in 2021 compared to 2020, the 2.8% reduction in estimated total deaths in England in 2021 (ex-COVID) resulted in a further slight reduction in PM2.5 attributable deaths to 26,731 in England in 2021 compared to 28,199 in 2020. This is likely to be an under-estimate given that a number of people dying due to COVID-19 may have died anyway due to other causes (due to the length of the pandemic).
New estimates for total deaths attributable to PM2.5 (and nitrogen dioxide (NO2)) in 2019 were published in the UK Health Security Agency’s report titled Chemical Hazards and Poisons Report: Issue 28 – June 2022. These used COMEAP’s updated methodology.
See pages 19 and 20 for new estimate of 29,000 to 43,000 deaths attributable to air pollution (PM2.5 and NO2) in 2019. This estimate replaces the previous estimate of 28,000 to 36,000 based on data from 2013.
CAL 493_UKHSA_CHaPR_AQ_Special_Edition_2206116_Deaths in 2019
Useful links and resources are shown in Section 8 and 9 below.
covid2020reftables4 per emails of 23 and 25 June 2022
London data, analysis and reports (March 2023)
Public Health Indicators for all regions in England (2018-2021)
Trends in boroughs in London region
Ranking of boroughs in London region
London Health Burden 2019 (published 25 January 2021 i.e. before new WHO air quality guidelines)
GLA ERG london_health_burden_of_current_air_pollution_and_future_health_benefits_of_mayoral_air_quality_policies_250121
See pages 19 and 20 for new estimate of 29,000 to 43,000 deaths attributable to air pollution (PM2.5 and NO2) in 2019. This estimate replaces the previous estimate of 28,000 to 36,000 based on data from 2013.
COMEAP Appendix_B_-_Summary_of_views_on_low-level_exposure_studies_January 2022
It is not known how this population-wide burden is spread across individuals in the population, but we can speculate between various possibilities. Our results are consistent with an average loss of life ranging at one extreme from 11½ years if air pollution was solely responsible for 29,000 deaths to, at the other extreme, six months if the timing of all deaths was influenced by air pollution. We believe both of these extremes to be extremely unlikely. Given that much of the impact of air pollution on mortality is linked with cardiovascular deaths, it is more reasonable to consider that air pollution may have made some contribution to the earlier deaths of up to 200,000 people in 2008, with an average loss of life of about two years per death affected, though that actual amount would vary between individuals. However, this assumption remains speculative.
Other useful information e.g. Years of Life Lost
Annual mean PM2.5 data for London
2021: 12.3 ug/m3 (11.8 ug/m3 anthropogenic)
2020: 11.9 ug/m3 (11.4 ug/m3 anthropogenic)
2019: 9.6 ug/m3 (8.9 ug/m3 anthropogenic)
2018: 8.7 ug/m3 (8.3 ug/m3 anthropogenic)
8. Update for 2020 data in 2022
The impact of COVID-19 in 2020 (and 2021) coincided with the World Health Organisation (WHO) updating its air quality guidelines on 21 September 2021.
The latter was followed by the Committee on the Medical Effects of Air Pollutants (COMEAP) recommending that the Concentration Response Function (CRF) used for quantification of mortality associated with long-term concentrations of PM2.5 should be increased from 6% to 8% per 10 ug/m3 annual average PM2.5.
As a result, the attributable fraction increased from 5.1% (in 2019) to 5.6% in England as a whole in 2020 despite lockdowns for COVID-19 reducing annual average PM2.5. The Office for Health Improvements and Disparities provided comparable data for 2018 and 2019 when it published the new 2020 data (using Defra’s annual average PM2.5 for each year and the new CRF from COMEAP). Like for like, the fall in total PM2.5 concentrations due to lockdowns (from 9.6 ug/m3 in 2019 to 7.5 ug/m3 in 2020) meant that the attributable fraction for England fell from 7.1% in 2019 to 5.6% in 2020.
The Office for National Statistics helped CAL to find the data needed to calculate the attributable deaths in each area and region in England excluding those attributed to COVID i.e. to estimate an underlying death rate (which was similar to previous years ex-COVID-19). These totalled 500,000 in 2020 (ex-COVID-19) compared to 496,000 in 2019.
Useful links and resources are shown immediately below.
CAL 463 COMEAP_Statement_on_PM2.5_mortality_quantification_January 2022
CAL 463 CAIC app_full_data_set_2020_V7_030722
CAL 463 popwmpm252019byUKcountry
CAL 463_popwmpm252020byUKcountry 030722
ONS: Deaths registered in England and Wales due to and involving coronavirus (COVID-19). Breakdowns include age, sex, region, local authority, Middle-layer Super Output Area (MSOA), indices of deprivation and place of death. Includes age-specific and age-standardised mortality rates. See the 2020 edition of the dataset. Note that the 2021 edition of this dataset was published on 1 July 2022.
CAL 463 ONS Table 7_covid2020reftables4 030722
9. Other useful resources
Copy of CAIC app 2018 update_Final 060720
Updated 26 February 2023