Investigating Air Pollution in Coventry, Wolverhampton and Worcester with ITV Central

A Message from ITV’s Environment Correspondent


We received a call from ITV’s Environment Correspondent, Charlotte Cross inviting us to participate in a special programme for the launch of Birmingham’s Clean Air Zone (CAZ) to be broadcast on ITV Central. Our on-going relationship with the broadcaster has seen our air quality monitors used to investigate local air pollution with ITV Central and ITV Wales This Week. Check out our previous work with ITV here.


ITV expressed their interest in using mobile air pollution monitoring equipment to measure air pollution in some of Birmingham’s surrounding cities, including Coventry, Wolverhampton, and Worcester. As the Zephyr® offers mobile monitoring and GPS capabilities, it was decided that it would be the perfect tool for ITV to employ to better understand air pollution as part of the programme. To monitor air pollution at each location, our Lead Data Scientist, Dr. Jordan White, and Charlotte would take walks around hotspot areas of each city with a Zephyr® inside of a backpack and analyse the data and our findings.


Measuring Mobile Air Pollution Levels in Coventry, Wolverhampton, and Worcester

EarthSense Lead Data Scientist, Dr. Jordan White with ITV's Environment Correspondent, Charlotte Cross on their journey in Coventry

Jordan installed a battery powered Zephyr® monitor inside a small backpack and took an early morning trip to the West Midlands to meet with Charlotte in Coventry. The walk commenced at 8am to catch the morning rush hour, which would capture tailpipe emissions, like nitrogen dioxide (NO2) and particulate matter (PM2.5) from the increased number of vehicles on the road.


The next stop was Wolverhampton, which Jordan and Charlotte both travelled to for the lunch time traffic. Once again, the walks commenced around the city with the Zephyr® loaded backpack to measure the levels of air pollution throughout the journeys. The last stop for their air pollution investigation was Worcester, which they reached mid-afternoon to catch the school pick up time.


The Results


After the journeys were carried out, Jordan analysed the data for each trip to identify the average concentrations for NO2 and PM2.5 for each location. He also identified the areas in each city where the highest concentrations of each pollutant were measured by the Zephyr®. Due to the monitors taking samples of the air quality every 10 seconds, it was kept in mind that some maximum measurements may have only been found in a specific sample during each journey and may not be indicative of the whole city.


Average and maximum measurements for NO2 and PM2.5 taken by the Zephyr® monitor

Overall, measurements taken by the Zephyr® monitor throughout the journeys highlighted that each city had average NO2 and PM2.5 levels below UK air quality hourly limits for NO2 (200ug/m3­) and 24 hour guidelines for PM2.5, (50µg/m3). In Worcester*, the average concentrations were interesting, as the walk in the city experienced the lowest average levels of NO2 but highest average levels of PM2.5, which may be due to different vehicle fleets and more diesel vehicles. In addition, Wolverhampton’s average NO2 concentrations were just at annual UK guidelines of exactly 40µg/m3.


The walking route around Coventry* was during a weekday rush hour and followed some of the city’s busy commuter routes – the Zephyr® recorded a maximum concentration of 81 µg/m3 for NO2, and 9 µg/m3 for PM2.5. These concentrations, though not alarming, represent an urban environment with a high density of traffic emission sources. Petrol and diesel fuelled vehicles contribute to degraded air quality – the health implications of prolonged exposure to such emission sources is understood to contribute to the ill-effects of long term respiratory and cardiovascular conditions. Meteorology has a substantial role in how polluted the air is at a given time in a given location. Faster wind speeds generally improve air quality, and sunshine initiates chemical processes that promote oxidation. During the walk around Coventry, the sky was overcast and the air was still, which may have contributed to elevated NO2 in combination with rush hour congestion.


Wolverhampton had the second highest maximum concentration for NO2 and highest measurement for PM2.5­. The walk taken by Jordan and Charlotte was at midday around the city centre, and the highest concentrations for NO2 were taken near the Molineux Stadium and ring road. Similar to Coventry, the areas with the highest levels may have been experiencing increased numbers of vehicle traffic contributing to elevated emissions.


Lastly, Worcester’s* highest Zephyr® measurements for NO2 appeared to be near the train station, Foregate Street Station and over the Worcester bridge. When walking along the River Severn by Worcester Cathedral, the air was significantly less polluted than on the surrounding roads, potentially due to more wind near the water and better ventilation, meaning cleaner air.


Real time map of NO2 levels taken by the Zephyr® monitor

What Does this Mean for Air Quality?


Air pollution is an ongoing problem that impacts billions of people across the world. UK air quality is trending towards improvement year on year but requires mitigations and management to keep the air safe for us all to breathe. Exposure to harmful pollutants is still commonplace and affects the poorest in society the greatest. There are still many people unnecessarily using private vehicles for very short journeys, which fills the air with toxins as well as other activities such domestic burning – but it isn’t too late for us to change our habits.


Initiatives like Birmingham’s new Clean Air Zone (CAZ) are intended to reduce air pollution emissions in city centres by discouraging people who have vehicles with high emissions from entering the zone. When entering the zone, drivers with vehicles that exceed predetermined emission standards are charged for entry within the area. There are 4 different types of Clean Air Zone which prevent individuals with different types of vehicles from entering the relevant zone. Birmingham’s Class D Clean Air Zone aims to stop buses, coaches, private hire vehicles, vans, minibuses, and cars from entering the city, reducing the amount of tailpipe emissions. More information on Birmingham CAZ is available here.


With strategies like this in place, it may encourage residents to make more sustainable decisions such as choosing to walk, cycle or take public transport where they can for the betterment of public health. Birmingham’s new CAZ may not be good news to everyone due to the need for costly electric vehicles, which are not affordable for some living in the city. To tackle this, the council have launched applications for exemption permits and financial incentives to purchase a vehicle which meets the emission standards. In addition, implementing air quality networks around the world and providing public information to communities means we can gather greater data points which pinpoint sources and hotspot locations, enabling us to make informed decisions to reduce such risks.


For more information about measuring air pollution levels with the Zephyr subscription…

Visit www.earthsense.co.uk/zephyr.


* Maximum concentrations taken with 10 second integrated data

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