Detailed information on London’s (UK) air pollution is now being published on breathelondon.org, the website for a new collaborative project to paint a clearer picture of the city’s air quality. The readings are being provided by a network of AQMesh air quality monitoring pods supplied and installed by Air Monitors, part of the ACOEM Group.
The AQMesh pods are stationary – mostly mounted discreetly on lamp posts, but the pod data is being supplemented by measurements from instruments that have been installed by Air Monitors in two Google Street View Cars, as they travel the city’s streets.
Visitors to the Breathe London website will be able to view almost live data (within an hour) on nitrogen dioxide (NO2); one of the urban pollutants of greatest concern.
“This is a major step forward,” says Felicity Sharp, Air Monitors Managing Director. “The availability of highly localised air quality data is critical to the empowerment of citizens so that they can make choices that affect the quality of the air they breathe.
“In the past, air quality data has not been sufficiently local to allow most citizens to change the way they live their lives, but with the benefit of this website they will be able to choose where they want to walk, run, play, go to school or even buy a house.
“The data will also help to raise awareness and thereby encourage citizens to choose more environmentally friendly transport modes, particularly in pollution hotspots.
“Importantly, the data will also help national and local government to assess the effectiveness of air quality improvement measures. So this is great news for London, and we hope that it will be replicated in similar smart city projects around the world.”
Schools near Glasgow have been monitoring air quality as part of a project aiming to reduce the levels of pollution emitted by vehicles as they drop off and collect children. The project is part of a ‘Beat the Street’ initiative that was granted £50,000 from a new £1million fund to increase walking, cycling and sustainable travel in Scotland. The overall aim is to cut Scotland’s carbon emissions, improve air quality, reverse the trend towards sedentary lifestyles and tackle health inequalities.
The Environmental Health department of East Renfrewshire Council supplied and installed the three AQMesh air quality monitoring pods that were utilised in the project. The monitoring activity followed initiatives in eight schools organised with SEPA, in which the children designed their own air quality banners as part of a competition.
The banners were then placed outside the schools which were then monitored for two weeks with an AQMesh pod measuring a variety of parameters including nitrogen dioxide – one of the pollutants of greatest concern. The Council’s Richard Mowat said: “We used one of our own AQMesh pods and rented the other two from Air Monitors. The pods are small and easy to install so we were able to locate them close to the areas most affected by parents’ vehicles.
“The results clearly showed significant peaks in pollution during the drop-off periods and it was pleasing to note how well the project was received. We hope that this work will help educate the children and that they, in turn, will encourage their parents to leave the cars at home and walk whenever possible.”
Anne-Marie Absolom is Head Teacher at one of the participating schools – St Clares Primary School. She said: “Our Junior Road Safety Officers, and all of the school staff, are delighted that we have had the opportunity to install temporary air quality monitors in our car park.
“We have been campaigning throughout the year to improve air quality in and around our school. The children have also been learning about the small changes that they can make – changes that will make a big difference to the quality of the air we breathe.
“The results from the monitors have highlighted the specific times of day at which air pollution is most significant, and the Junior Road Safety Officers are now campaigning at these times. The data gathered has been shared with all children in the school and they are passionate about spreading the word and ensuring that air pollution is reduced.”
As well as supplying the monitoring equipment for the project, Air Monitors also provided sponsorship funds for the school banners, and this was reflected in a stunning night-time time display on the roof of Glasgow’s famous SEC Armadillo, organised by SEPA. A variety of images relating to air quality were projected on to the Armadillo’s roof, highlighting for example Clean Air Day 2019, as well as the Air Monitors logo.
SEPA’s Dr Colin Gillespie said: “It has been great to work again with Air Monitors and the councils, raising awareness in air quality around schools, promoting active changes to reduce pollution and encouraging pupils to think about more sustainable forms of travel.”
Following a successful evaluation phase in 2018, AQMesh small sensor air quality monitoring ‘pods’ have been selected for use in a project to control the ventilation of a road tunnel in the city of Marseille.
Supported by the AtmoSud (AirPACA) local air quality monitoring network, the CETU (Tunnel Studies Centre) and AQMesh distributor Addair, eight AQMesh pods were installed in February 2019, monitoring nitrogen oxides NO and NO2, in an innovative experiment in one of the covered sections of the L2 ring road in Marseille. Called “Boreas project”, after legendary ‘dispersing’ winds, this study aims to use pollution measurements near tunnel entrances to activate in-tunnel fans.
Urban planning is increasingly routing vehicles underground. Although this approach eases air quality and noise at some locations – and overall reduces the level of pollution the population is exposed to – there is a risk that residents living close to the tunnel heads are actually exposed to higher concentrations of pollution as air is expelled from the tunnel.
The L2 ring road in Marseille consists of a succession of covered tunnels over 12Km in dense urban areas. The phased project at the Montolivet South tunnel heads will implement a system for the conditional triggering of in-tunnel fans to evaluate its impact on air quality in the zones adjacent to the nearest residents. This approach was tested in 2018, with micro-sensor readings compared at the AirPACA Kaddouze monitoring station. A first phase analyses the pollution without activation of the ventilation system, then a second phase with ventilation.
The aim is to determine the link between ventilation and dispersion of the pollution at the end of the tunnel and to determine the most effective protocol for activation of the ventilation systems based on real-time air quality levels, inside and outside the tunnel. Automated alerts for high NO2 levels are already in place. The feasibility of this approach will also be reviewed by analysing efficiency in terms of cost and energy consumption. In theory, the use of ventilation could improve the quality of air at the head of the tunnel. However, in some weather conditions this could simply displace the pollution and this forms part of the study – analysing the pollution concentration and dispersion in different meteorological and traffic conditions.
AQMesh has been used in other tunnel monitoring projects, including several in the UK, specifically to study ventilation efficiency in road tunnels where pollution can build up if sufficient air flow is not maintained. During the UK projects, AQMesh pods were also first co-located with a nearby reference station to ensure measurements were directly comparable.
The pods were then deployed at different positions within the tunnels and in ventilation ducts, studying how the concentration of pollution changed when air flows were adjusted in varying traffic scenarios. The pods were able to run for up to six months without any maintenance or calibration, despite the very high pollution levels recorded. The results obtained in these studies enabled optimisation of the ventilation settings and helped to reduce energy consumption whilst maintaining cleaner air for tunnel users and maintenance personnel.
Suite à une phase d’évaluation et en raison de sa qualité de mesure, la solution AQMesh a été sélectionnée dans le cadre d’un projet d’asservissement de la ventilation d’un tunnel routier dans la ville de Marseille. Ce projet, porté par le réseau de surveillance de la qualité de l’air local AtmoSud et le CETU (Centre d’Etudes des Tunnels), a vu l’installation de 8 capteurs AQMesh en février 2019 pour le suivi des oxydes d’azotes NO et NO2.
Pour réduire la pollution de l’air aux sorties des tunnels et ainsi limiter l’exposition des riverains, AtmoSud et le CETU (Centre d’Etudes des Tunnels) testent un dispositif innovant basé sur l’activation de la ventilation par des micro-capteurs. Ces derniers, installés début février 2019 par AtmoSud, enregistrent les données sur le terrain pour une phase d’observation, avant de passer à la phase test de déclenchement de la ventilation.
L’implantation des 8 micro-capteurs a été décidée en concertation avec les acteurs
L’adaptation de la ventilation aux niveaux de pollution mesurés en tête de tunnel n’a jamais été mise en œuvre à ce jour et constitue donc une réelle innovation.
Comme pour tout projet innovant, les phases de concertation à chaque étape sont essentielles. Celle du choix de l’emplacement des micro-capteurs l’a été particulièrement.
AtmoSud a donc consulté et les différents acteurs : la DREAL PACA, l’association CAN L2, les services de la mairie de secteur du 11e/12e arrondissement de Marseille, le CETU (Centre d’Etudes des Tunnels), la métropole Aix-Marseille Provence et la Région Sud Provence-Alpes-Côte d’Azur.
Des micro-capteurs soigneusement étalonnés par AtmoSud
Le monoxyde d’azote (NO) et le dioxyde d’azote (NO2), marqueurs du trafic automobile sont les polluants qui vont être mesurés en 8 points. Avant de procéder à leur installation, AtmoSud s’est assuré de la fiabilité des données qui vont être recueillies, en testant les capteurs dans la station de mesure Kaddouz, à proximité de la L2. La phase d’observation va se dérouler sur une période de 3 à 6 mois.
In an inter-connected world, air quality is increasingly becoming another measurement made available to the public, but how reliable is the data?
Common air pollutants such as NO2 and PM2.5 mix at different rates depending on their source and local weather conditions, particularly wind speed, leaving large local variations in pollution levels. Urban air quality has traditionally been managed by authorities using a combination of large, compliance standard (reference) measurement stations and modelling based on an emissions inventory. Research has shown that increasing the number of measurement points improves the spatial resolution of urban air quality models.
Small-sensor air quality monitoring technology offers the possibility of more local measurements, and its emergence coincides with the appetite from Internet of Things (IoT) developers to map air quality across cities in real-time and communicate this information to the city inhabitants in various ways. This is leading to a growing number of smart city projects using a range of monitoring devices, but understanding the air quality information gathered and sharing it with the public can still be complicated.
Many air quality sensors that are small, cheap and have low power consumption are often very limited by the influence of fluctuating temperatures and cross-gas effects and do not produce good air quality readings. It is therefore beneficial to use a small-sensor air quality monitoring system that incorporates processing, correction and a QA/QC process in order to offer meaningful readings. Environmental authorities, including the US EPA, have developed air quality indices (AQI) and other tools to communicate local air quality to the public. These authorities are looking at how to modify that approach to provide more localised information from small sensor-sensor systems, such as air quality in a neighbourhood – or even a street – rather than a whole section of a city.
AQMesh, a small-sensor air quality monitoring system, is being used in a variety of successful smart city projects which have a range of objectives, but with a common goal of informing the public about the air quality and pollution levels in the local area where they live and work.
‘Breathe London’ was launched in February, with a sophisticated network of air quality monitors to help investigate and improve London’s toxic air. A range of fixed and mobile sensors will be used to build up a real-time, hyperlocal image of London’s air quality. The technology company Air Monitors designed and installed the network of AQMesh air quality monitoring pods, as well as the air quality analysers that were specially adapted to operate inside Google Street View cars.
In Minneapolis, Minnesota Pollution Control Agency (MPCA) has deployed 50 AQMesh pods across 50 zip code areas in order improve understanding of the small-scale differences in air pollution within urban areas.
Similarly in Newcastle, 55 AQMesh pods, supplied and supported by Air Monitors, form part of a network of over 600 sensors managed by the UK’s first Urban Observatory, which aims to provide Newcastle’s citizens with a digital view of how cities work.
These smart cities demonstrate that meaningful and reliable air quality information can be shared with the public when networks are deployed effectively and supported by air quality professionals who understand the capabilities – and limitations – of small-sensor technology and how the local environment affects air quality readings.
The UK’s first Urban Observatory, led by Newcastle University, has been designed to provide a digital view of how cities work. AQMesh air quality monitoring equipment is being deployed across Newcastle and Gateshead in conjunction with other instruments for monitoring parameters such as air and water quality, noise, weather, energy use, traffic and even tweets.
Forming part of a network of over 600 sensors, the Urban Observatory has already collected over half a billion data points and the information is now starting to shed light on the way different systems interact across the city and provide a baseline against which future cities can be developed and managed.
To date Air Monitors, UK AQMesh distributor, has supplied 55 AQMesh pods and 6 conventional air quality monitoring stations. The conventional stations employ standard reference method instruments to measure key air quality parameters such as Nitrogen Dioxide, Ozone, Carbon Monoxide and Particulates. The AQMesh pods monitor similar parameters, but are smaller, solar-powered, wireless, web-enabled devices that can be quickly and easily located in almost any location.
Commenting on Air Monitors’ involvement in the Urban Observatory project, Managing Director Jim Mills says: “The conventional stations are delivering precise, accurate data, and the AQMesh pods are providing the portability and flexibility to monitor air quality accurately and reliably in the locations of greatest interest.”
“Perhaps the most interesting aspect of this project is its ability to engage with the community, providing detailed local air quality data so that both authorities and citizens can make informed decisions on how to reduce exposure to air pollution. Looking forward, it is clear that work in Newcastle will serve as a model for other cities around the world to follow.”
The National Observatories facility was established in 2017 with the Newcastle Urban Observatory as the founding member, supported by £8.5 million investment from EPSRC (Engineering and Physical Sciences Research Council). The guiding principles are to be technology agnostic and vendor non-exclusive, open by default and transparent by design whilst developing a valued, long-term, sustainable platform. In order for the data to be useful to better understand cities and to facilitate evidence based decision-making across a range of scales and sectors, the data needs to be robust and reliable with known data quality that can be validated.
The AQMesh pods are also being used as part of the ‘Sense My Street’ tool box which enables local communities to deploy sensors and locate them on the streets, collecting evidence to inform or even change their communities.
Phil James, who co-leads the Urban Observatory research, explains: “Cities are complex environments and if we want to develop them sustainably we have to understand how everything interacts.
“By compiling observations and comparing the data, for the first time we are now able to make more informed decisions about designing our cities to work better for people and the environment. Through the Sense my Street project, we are able to give communities the power to gather data relevant to issues that are important to them at a very local scale.”
All of the data is freely available at Newcastle University’s website: www.urbanobservatory.ac.uk, and is being used by researchers, local authorities, regulators, developers, town planners, businesses and members of the public.
On Sunday 13th May 2018, Cardiff Council organised a car-free day in the city’s central area. As a result of this event air quality monitoring data showed an average 69% drop in nitrogen dioxide (NO2) – one of the pollutants of greatest public health concern. Seeking a better understanding of the relationship between air quality and traffic, Cardiff Council hired three AQMesh air quality monitoring pods from Air Monitors Ltd. The instruments were located on streets impacted by the day’s event, and within two of the Councils Air Quality Management Areas (AQMAs); City Centre & Stephenson Court, Newport Road. The instruments continuously recorded air quality at these locations for 20 days before, during and after the event.
“In comparing the results obtained during the Car Free Day Event with results from the following Sunday (20th May) , the monitor on Duke Street showed an 87% reduction in nitrogen dioxide, the monitor in Westgate Street showed an 84% reduction and the third monitor, which was located less centrally from the main road closures, in Stephenson Court, showed a 36% reduction,” commented a Specialist Services Officer, working for Shared Regulatory Services (SRS) on behalf of Cardiff Council . “Comparing the car-free datasets with those of the following Sunday (20th May); the daily average nitrogen dioxide levels recorded by two of the monitors situated within the City Centre AQMA exceeded the EU yearly average limit (40 µg/m3), but on the car-free day, these two monitors measured daily average figures of just 5 and 8µg/m3 of nitrogen dioxide, providing clear evidence that air pollution in Cardiff city centre is generated by traffic.”
Under the European Ambient Air Quality Directive, Welsh Ministers have a duty to ensure that compliance with air quality objectives defined within the directive is achieved. As outlined in Defra’s UK Action Plan for tackling roadside nitrogen dioxide concentrations, July 2017, modelling has indicated that certain road networks in Cardiff fail to meet EU air quality requirements. Cardiff Council has been directed by Welsh Government to undertake a feasibility study, in order to demonstrate how compliance with the directive and its specified limits will be achieved in the shortest time possible. In order to implement air quality interventions, the Council therefore needs to evaluate the sources of pollution so that appropriate interventions can be assessed to ensure that effective mitigation measures can be implemented. At the same time, it will be necessary to engage with citizens to ensure that they appreciate the importance of tackling air pollution.
Nitrogen dioxide and particulates are the main cause of failures to meet EU air quality limits in cities around the world, and it is well known that traffic, and diesel vehicles in particular, are a major source of these pollutants. The AQMesh pods measure a range of gases including nitrogen dioxide, so by monitoring the effect of removing traffic, the Council will be in a better position to implement improvement measures.
Two automatic air quality monitoring stations are located in Cardiff, and the Council supplements the data from these monitors with a network of non-automatic passive diffusion tubes. However, the Specialist Services Officer from SRS says: “The fixed stations can’t provide street-level monitoring at the most sensitive locations, and the use of diffusion tubes does not provide a detailed understanding of daily trends as they only provide a monthly average figure. However, SRS are aware of the capabilities of the AQMesh pods and are familiar with the accuracy and flexibility that they are able to deliver, which is why they were chosen for the car-free day project.”
In order to assure the quality of the monitoring data, the AQMesh pods that were employed during the project were checked against a reference station and were found to have performed very well. “The pods are small, lightweight and battery-powered which makes them quick and easy to deploy,” the Specialist Services Officer adds. “This is crucial to our work because it gives us the ability to site them on lamp posts so that they measure the air that people are breathing. In addition, they are web-enabled which means that we can monitor air quality in almost real-time; providing a unique insight into the specific events that impact air quality.”
It has been estimated that around 40,000 people in the UK die prematurely as a result of air pollution, mainly in the larger towns and cities. In Wales, the urban areas exceeding EU limits include Cardiff, Swansea, Port Talbot, Newport, Chepstow and Wrexham.
Following completion of the monitoring work in Cardiff, SRS has had requests for the data from a number of organisations, and are keen for the work to be publicised as widely as possible. Highlighting the importance of citizen engagement, the SRS Specialist Services Officer says: “A wide variety of potential measures are available to combat air pollution in Cardiff, but many involve inconvenience for members of the public and cost to the public purse, so we need those affected to be on-board with the measures being taken. We are also hoping that the public will be keen to help, by participating in car-share schemes for example.”
London Mayor Sadiq Khan has launched a new, street-by-street monitoring system that will help to improve that capital’s air quality. From July 2018, and operating for a year, London will benefit from what is being described as the world’s most sophisticated air quality monitoring system. A consortium involving academia, an environmental charity, and commercial partners will install a network of 100 multiparameter AQMesh air quality monitors, whilst also operating two Google Street View cars that will map air pollution at an unprecedented level of detail.
Air Monitors Ltd will supply the AQMesh pods and manage data from all the sensor systems, so that air quality can be visualised and mapped in almost real-time. Working closely with the Greater London Authority, the project will be run by a team of air quality experts led by the charity Environmental Defense Fund Europe, in partnership with Air Monitors Ltd., Google Earth Outreach, Cambridge Environmental Research Consultants, University of Cambridge, National Physical Laboratory, King’s College London and the Environmental Defense Fund team in the United States.
Air Monitors Managing Director Jim Mills says: “It is difficult to underestimate the importance of this project – traditional monitoring networks provide essential information to check compliance against air quality standards, but this network will be ‘hyperlocal’ by which we mean that it will deliver street-level air quality data, which will be of tremendous interest to the public and also enable the effective assessment of air quality interventions.
“The Google Street View cars will take readings every 30 meters, helping us to find pollution hot-spots, so that AQMesh pods can be positioned in these locations. However, the pods are wireless and independently powered, so they can also be quickly and easily fixed to lamp posts in other sensitive locations such as schools.”
In addition to nitrogen dioxide and particulates, which are the pollutants of greatest concern, the pods will also measure ozone, nitric oxide, carbon dioxide, temperature, humidity and pressure. Data will sent, near real-time, to Air Monitors’ cloud-based data management system, which can be accessed by PC, tablet or smartphone by authorised partners, using an assigned login.
The monitoring data will provide baseline air quality data that will be essential in the assessment of mitigation measures, particularly in London’s expanding ultra-low emission zone. For example, on 20th June 2018, Sadiq Khan, announced the creation of the largest double-decker electric bus fleet in Europe, and the new monitoring network will enable the assessment of this initiative’s impact on air quality.
“This project will provide a step change in data collection and analysis that will enable London to evaluate the impact of both air quality and climate change policies and develop responsive interventions,” said Executive Director for Environmental Defense Fund Europe, Baroness Bryony Worthington. “A clear output of the project will be a revolutionary air monitoring model and intervention approach that can be replicated cost-effectively across other UK cities and globally, with a focus on C40 cities.”
Mark Watts, C40, Executive Director said: “Almost every major city in the world is dealing with the threat of toxic air pollution, which is taking an incredible toll on the health of citizens, public finances, quality of life and contributing to climate change. London is already a world leader in responding to this global threat and with this initiative it will set a new global standard for how street level air quality monitoring can inform strategic policy making. Cities across the C40 network and around the world will be watching closely to understand how this monitoring can deliver cleaner air for their citizens.”
About Environmental Defense Fund
Environmental Defense Fund Europe is a registered charity (1164661) in England and Wales. A recently established affiliate of leading international non-profit Environmental Defense Fund (EDF), the organisation links science, economics, law, and innovative private-sector partnerships to create transformational solutions to the most serious environmental problems. Connect with us at edf.org/europe, on Twitter and on our EDF Voices, EDF+Business and Energy Exchange blogs.
About Air Monitors Limited
Air Monitors is the UK’s leading air quality monitoring company, supplying and supporting instrumentation to central government, local authorities, research and industry. Air Monitors supplies and supports AQMesh in the UK and will also provide and maintain the equipment within the Google Street View cars in the project.
AQMesh is a fully developed and independently evaluated small sensor outdoor air quality monitoring system, manufactured in the UK by Environmental Instruments Ltd. and in use worldwide since 2012.
About Cambridge Environmental Research Consultants
Cambridge Environmental Research Consultants (CERC) are world leading developers of air quality modelling software. Their renowned ADMS-Urban model will be used together with the sensor data to generate hyper-local air quality mapping both for nowcasts and forecasts, and for policy studies.
About Google Earth Outreach
Google Earth Outreach is a program from Google designed specifically to help non-profit and public benefit organisations around the world leverage the power of Google Maps and Cloud technology to help address the world’s most pressing social and environmental problems.
About the National Physical Laboratory (NPL)
NPL is the UK’s National Measurement Institute, providing the measurement capability that underpins the UK’s prosperity and quality of life. Every day our science, engineering and technology makes a difference to some of the biggest national and international challenges, including addressing air quality issues. http://www.npl.co.uk/about/what-is-npl/
About University of Cambridge Department of Chemistry
The University of Cambridge Department of Chemistry is a world leading research and teaching institution. At Cambridge, the Centre for Atmospheric Science has played a primary role in the development of low-cost sensors for air quality monitoring and in the development of techniques for analysing and interpreting measurements from sensor networks.
About the C40 Cities Climate Leadership Group
Around the world, C40 Cities connects 96 of the world’s greatest cities to take bold climate action, leading the way towards a healthier and more sustainable future. Representing 700+ million citizens and one quarter of the global economy, mayors of the C40 cities are committed to delivering on the most ambitious goals of the Paris Agreement at the local level, as well as to cleaning the air we breathe. The current chair of C40 is Mayor of Paris Anne Hidalgo; and three-term Mayor of New York City Michael R. Bloomberg serves as President of the Board. C40’s work is made possible by our three strategic funders: Bloomberg Philanthropies, Children’s Investment Fund Foundation (CIFF), and Realdania.
Extensive research has shown that indoor air quality is often worse than outdoors. Closed system buildings trap harmful particles inside, and external air intakes can bring in more polluted air from outside.
Whilst many heating, ventilation and air conditioning systems (HVAC) use particle filtering, managed through air exchanges, they can often worsen levels of polluting gases, such as NO2 – now classified by the World Health Organisation as a Class 1 carcinogen. Natural ventilation systems have no particulate filtration at all, and buildings are also frequently completely shut up all night with no ventilation running, trapping the pollution that has built up over the day.
Unlike outdoor air quality (which the government is responsible for), indoor air quality is the responsibility of the building owner or manager, and with research proving that poor air quality has a significant impact on human health, air pollution should be a key factor of employee health & safety.
Future Decisions has teamed up with AQMesh and UK distributor, Air Monitors Ltd, to supply pollution mitigation to improve indoor air quality. Future Decisions has developed patented smart management strategies that aim to reduce internal air pollution by 30% – this is usually enough to bring the air quality within UK & EU regulatory levels, and often within the World Health Organisation levels.
AQMesh measures NO, NO2, O3, NOx, CO, CO2, SO2, PM1, PM2.5, PM10, temperature, pressure and relative humidity in a small pod which can be mounted both indoors and outdoors on a wall or post. Batteries, solar power and DC power options give flexibility of mounting anywhere. AQMesh was designed to offer an easy-to-use air quality monitoring system that can deliver localised real-time readings, improving the accuracy and scope of gathering air quality data in order to support initiatives to reduce air pollution and its risk to human health.
Minnesota Pollution Control Agency (MPCA) has purchased fifty AQMesh pods to measure key air pollution gases and particulate matter across fifty different zip code areas. These small sensor air quality monitoring systems measure NO, NO2, O3, CO, SO2, PM1, PM2.5, PM10, temperature, pressure and relative humidity and will be installed – one per zip code – around the twin cities of Minneapolis and Saint Paul. The two-year project, funded by a legislative grant*, is to supplement the air quality information available to the public.
Deployment across the 50 zip codes has been mapped out after several public meetings involving the local community to determine where residents felt monitoring was needed. The small yellow triangles represent the points which local residents asked for sensors to be installed, and the green dots indicate the planned installation site based on the infrastructure available for mounting the AQMesh pods.
“This project is about understanding small-scale differences in air pollution in urban areas in order to minimise exposure to harmful air pollutants, particularly for vulnerable communities. The Assessing Urban Air Quality project will use new air monitoring sensors to broaden our knowledge about air quality in Minneapolis and St. Paul”, commented Monika Vadali, Ph.D, who is leading the project.
The pods are currently installed at the Blaine airport Federal Equivalent Method (FEM) station so that AQMesh readings can be compared to and validated against air quality readings taken using this US approved methodology, with scaling then applied if necessary. The MPCA team intends to install the pods in each zip code during the next month or two. The pods will be powered using a bespoke solar power pack: 30W panels have been specified for such a northern location, compared to the 15W normally required to supply the low-power AQMesh platform. The pods can be battery powered but 12V DC supply was specified, given the 2-year project timescale.
The pods were installed in November 2017 and have achieved 100% uptime to date, including during severe weather conditions, with temperatures below -25°C / -15°F and heavy snow. Initial comparisons against co-located pods show a high level of pod-to-pod precision, with an average R2 of 0.94 for NO2, 0.92 for O3 and 0.93 for PM2.5.
The 50 pods have been compared to the FEM station in two batches of 25, and the first batch of comparisons show an average co-location comparison correlation R2 of 0.74 for O3 and NO2, 0.86 for PM2.5, 0.93 for PM10 and 0.82 for NO. The reference CO showed a baseline shift part way through the comparison period, so that comparison is being reviewed. The SO2 R2 was depressed by a max FEM reading of 2.5ppb, with low FEM resolution, but AQMesh readings were within +/- 2ppb of reference.
The MPCA team is setting up an API connection to the AQMesh server, allowing air quality data to be streamed, near real-time, to the MPCA server, from which it can be published.
AQMesh is in use at various locations in the USA, as well as 35 other countries. The pods deployed in Minnesota are the current production version (v4.2.3).
More information about the MPCA project is available at https://www.pca.state.mn.us/air/assessing-urban-air-quality-project.
* The project is funded by a legislative grant: Environment and Natural Resources Trust Fund (ENRTF) M.L. 2017, Chp.96, Sec. 2. Subd.07b