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.
Supporting the aims of Clean Air Day today, 20th June 2019, the Guardian has published a short film demonstrating the changing levels of pollution that children are exposed to as they walk to school in London. The film can be viewed here.
The Guardian Cities team worked closely with their colleagues in multimedia to create a film showing real-time air quality data as a mother takes her young children to school in north London. The video features mother-of-two Natasa pushing a pram and walking her daughter along Marylebone Road, with a Particles Plus instrument attached to the pram and an AQMesh pod on her daughter’s backpack.
The most important air quality parameters are displayed on-screen during the walk, with data including PM10, PM2.5 and nitrogen dioxide (NO2). The film producers have cleverly integrated the European yearly mean limits for these parameters into the display, with readings changing from blue to red when they exceed the limit, (which for PM10 and NO2 was most of the time!).
Documentary producer Anetta Jones, said: “Air quality is a vitally important issue for the health and wellbeing of city dwellers, but the main pollution threats are invisible, so we hope that initiatives such as this will help residents and visitors to better understand the threat that they face.”
The monitoring equipment was supplied by Air Monitors Limited. Their David Green said: “We have recently installed large numbers of AQMesh pods all over London as part of the Breathe London project, and data from these pods will be displayed on the project website. However, video is an enormously popular medium, and it is really exciting to see what can be achieved when the latest technologies in multimedia and air quality monitoring combine.”
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.
A new network of air pollution monitors has been installed to record emissions from cruise ships docking in Greenwich.
The £80,000 network has been funded by the Port of London Authority (PLA) and installed in partnership with Breathe London and the borough councils covering both Greenwich and Tower Hamlets.
The eight monitoring stations, all located close to the Greenwich Ship Tier landing stage, will capture data around the clock with the raw data available via the websites of both the PLA and Breathe London. A full analysis of the results will be published in early 2020.
The monitors have been supplied by Gloucestershire-based Air Monitors Limited.
Robin Mortimer, PLA chief executive said: ‘The data these monitors collect will give us a comprehensive understanding of the impact that the cruise ships have on air quality when they are in town.
‘It’s crucial to have this information so that we can address the concerns that we know are very strongly held by local residents.’
The monitors are part of the PLA’s Air Quality Strategy, published in May 2018, the first to be produced by a UK port. It includes 25-year targets to halve levels of Nitrogen Oxides and Particular Matter from river-related sources, whilst growing use of the river for carrying both freight and passengers.
Measures already implemented include a programme of retrofitting older vessels with the latest environmentally-friendly technology.
In January, the Department for Transport (DfT) published the first-ever maritime strategy, which details their vision of a zero-emission shipping industry by 2050.
In it, the government said they are considering introducing targets to drive down emissions of GHGs and other air pollutants from UK shipping as ‘the volume of global trade increases.’
They also say they hope to have a group of hydrogen or ammonia powered domestic vessels in operation and at least one major ‘smart port’ in the UK to have all ship-side activity zero emission (including non-road mobile machinery like cranes).
The AQMesh small sensor air quality monitoring system already offers flexibility of monitoring location – through independent power and communications – as well as high data quality and traceability. Now the platform is even more flexible offering up to 20 different data channels. The wide range of sensors, including gases such as NO2, particulate matter (PM1, PM2.5 and PM10) wind and noise can be specified, from a single sensor to a ‘fully loaded’ mini air quality monitoring station.
The small, post-mounted monitoring pod sends raw sensor output to the AQMesh server using the mobile phone network and readings can be accessed by a secure login or API connection. Cloud data management allows settings to be changed online and makes a high level of remote support possible – ideal for monitoring in distant or hard-to-reach locations. Recent developments for 2019 mean that AQMesh offers an increased level of modularity unrivalled by any other small-sensor air quality monitoring system.
The full range of sensors includes gases NO, NO2, O3, CO, SO2, H2S and CO2. Recent work has shown the value of measuring a targeted combination of gases for a given application. For example, H2S and SO2 is popular with the oil and gas industry and measurement of CO2 is valuable as an indicator of combustion to calculate an index. The new wind speed and direction module means local pollution source apportionment can be carried out. All AQMesh pods measure environmental conditions – temperature, atmospheric pressure and RH% – in the same compact unit.
New pods can be built to almost any configuration and modifications can be and are carried out to existing pods returned to the factory. Some modifications are also possible in the field, such as adding extra gas sensors.
Most AQMesh pods are now powered using solar power and the new AQMesh solar module allows the pod and solar pack to be mounted on the same post, using the standard clips supplied, with the power cable simply connected together to start monitoring. The updated solar pack comes as a complete package with a 20W panel, more efficient charging, an additional port for powering two pods, and is now a smart system with a Bluetooth mobile app for checking the output of the panel and running basic diagnostics. Battery and direct (9-24V DC) power options are available.
AQMeshData.net is the AQMesh server which performs secure data processing using carefully developed, unique correction algorithms which compensate for cross-gas effects and environmental factors. AQMesh algorithms are fixed by version and completely traceable, with no use of machine learning or artificial intelligence. Continual development of these algorithms, using datasets from around the world which compare AQMesh readings with co-located reference data, allows AQMesh to demonstrate outstanding, accurate and repeatable performance when co-located against certified reference or equivalent methods, in any part of the world.
AQMesh pods require very little ongoing maintenance, meaning the cost of ownership remains low. Sensor replacement is recommended every 2 years and the demonstrated data stability is very high. AQMesh users also benefit from dedicated, global support from its UK base, where it is designed, developed, manufactured and distributed, as well as a network of trained distributors.
Few people know how clean the air is where they live, work, exercise or where their children go to school. Although air quality can be shown to vary significantly over short distances, air pollution is generally measured using a small number of large, expensive and high quality monitoring stations. The equipment used in these stations is very accurate and complies with measurement standards but they are expensive to buy and maintain, as well as difficult to position because of their size and infrastructure requirements.
With most cities having a single figure number of reference stations at best, many neighbourhoods do not have access to regular and localised air quality information. Historically, the best solution currently is to fill the gaps through modelling, which combines available air quality readings with other information such as emissions inventory.
Demand from communities for better local air quality information is coming at a time when development of smaller, cheaper air quality sensors can provide a solution to the challenge. ‘Small sensor’ air quality systems can provide highly localised pollution measurements, including nitrogen dioxide (NO2) and the key particulate matter measurement, PM2.5, but to provide meaningful measurements on which communities and authorities can make decisions, the information must show traceability to reference measurements.
Many initiatives around the world are aiming to show what can be done, with one of the most ambitious being the Breathe London project in London. 100 small sensor systems are being used, in combination with data from London’s reference network, modelling and readings taken by Google cars modified to carry high quality air monitoring equipment. This project aims to demonstrate how such a ‘hyper-local’ network can be managed, creating a template which can be rolled out to other cities worldwide.
Similarly, 50 AQMesh small sensor air quality monitoring units have been installed to monitor air quality in each of the 50 zip codes in Minneapolis – Saint Paul, USA. “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.
AQMesh has also been used to monitor air quality around industrial sites and next to nearby communities which may be affected. As the monitoring units can be positioned with a high degree of flexibility, such as mounting on a lamp post, it is possible to capture data at exactly the point required. With measurements usually every 15 minutes, combined with local wind speed and direction information, it is possible to build up a highly localised picture of likely pollution exposure and identification of pollution sources.
Whilst regulatory authorities are currently defining testing methodologies to help users choose small sensor air quality systems, the best small sensor systems provide a useful and practical tool to supplement existing monitoring networks and are in active use around the world, providing new information about local air quality for a range of applications.
North Americans will be well aware of the particularly harsh weather in the early months of 2019, but AQMesh has taken conditions in its stride. The AQMesh stated operating range of -20°C to + 40°C is backed up by long-term operation across a wide range of climates.
AQMesh pods used by Minnesota Pollution Control Agency (MPCA) to measure pollutant gases and particulate matter, such as NO2 and PM2.5 , installed on streetlights around Minneapolis St. Paul have seen temperatures as low as -25.4°C (-13.7°F) and continue to run smoothly.
Monika Vadali, leading the MPCA project, commented “We are quite impressed with the temperatures we have seen this winter”. However, when asked for a photo of the pods, she said “I can’t get to any of the pods as we have had so much snow and cold that there is 5-6ft of snow around some of the poles, making access difficult.” Temperatures recorded elsewhere have not been so low this year but AQMesh pods have been installed over previous winter in Sweden, Finland, Canada and central Europe, with temperatures regularly dropping below -20°C.
Despite such harsh weather conditions, the AQMesh pods have continued to monitor and communicate data to the AQMesh server, where it is securely accessed by users. The hardware design has been refined to ensure the equipment has the resilience to survive, with minimal maintenance, for years. The initial concept was for the pod to measure pollutant gases, particularly NO2, for two years on a single lithium battery. Although many users now run shorter projects or choose solar or DC power sources, the principle – and challenge – is unchanged.
In addition to its physical design, data processing on the AQMesh server includes carefully developed correction algorithms which compensate for extreme conditions. Remote diagnostics also identify unexpected patterns in sensor output, which may affect confidence in the data, which is then flagged.
At the same time as the AQMesh pods were under several feet of snow in Minnesota, pods in the southern hemisphere have been regularly operating at temperatures in excess of 30°C, hitting 44.7°C in South Africa and 46.2°C in Australia.
AQMesh pods have been deployed long-term (many pods are in their sixth year of deployment around the world) and as temperatures rise across some of the hottest locations where pods are deployed – Kurdistan, Pakistan, Myanmar, Arizona (USA), Ghana – the latest generation of sensors and processing algorithm will continue to provide reliable and traceable air quality measurements in locations where other monitoring equipment cannot readily be deployed.
In the southern regions of the USA, with very hot temperatures and varying levels of humidity, AQMesh pods maintained high precision and accuracy against co-located certified reference equipment, with a correlation R2 of 0.92 for ozone, compared to collated FEM. Many parts of the world where AQMesh operates record relative humidity (RH%) over 90%, often on a regular or sustained basis.
AQMesh also stands up to high winds and extreme rainfall and is now available with an optional wind speed and direction sensor to complement its extensive range of measurable parameters. The meteorological data gathered by this sensor can help distinguish between local and regional sources of pollution.
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.