City’s pollution at ‘danger’ level despite lockdown
EXPERTS DISCOVER HIGH READINGS IN SEVERAL AREAS
AREAS of Manchester city centre still recorded ‘dangerously high’ levels of pollution weeks into lockdown, experts have found.
In some areas of Manchester nitrogen oxide readings dropped by more than 40 per cent in the three weeks after the coronavirus lockdown began.
But several sites, such as the Mancunian Way, continued to have high levels of the pollutant.
Scientists at Manchester Metropolitan University say this could be because transport doesn’t account for all pollution – industry, residential and commercial gas and oil combustion all play a part.
“The decrease in heavy traffic has done an incredible job in reducing some of the city’s harmful pollution levels, as we have seen from the data, but we cannot ignore the bigger picture and other sources of harmful pollution,” Dr Sanja Potgieter-Vermaak, senior lecturer in Chemistry and Environmental Science at Manchester Metropolitan, said.
Experts have analysed data from a unique network of smart air quality sensors installed across the city centre.
Scientists from Manchester Metropolitan University studied levels of nitrogen oxide (NO2) using realtime data provided by the network of almost 100 connected monitors, which were deployed just before lockdown measures were introduced.
These units have been installed in different locations across the city as part of a new partnership project between Manchester based universities, Transport for Greater Manchester and AirSensa – a company specialising in air quality monitoring technology.
Nitrogen oxide is a toxic pollutant often associated with vehicle emissions and is known to cause severe health problems including inflammation of the lining of the lungs. The team analysed pilot data from nine sensors at different sites and found that in the threeweek period before lockdown began at the end of March, six of those nine sites exceeded the recommended annual limits for NO2.
But three weeks into lockdown, four of these sites still exceeded this limit – showing that despite an overall drop in pollution, levels of NO2 may still be dangerously high in some areas.
Some of the biggest drops in NO2 were found in the Manchester Piccadilly area, which reported a 38 per cent average drop in the pollutant three weeks into lockdown.
Oxford Road saw a massive 43pc decrease in NO2.
However, in other areas of the city, relatively low drops in NO2 were reported.
In the region of just 10pc was recorded in areas around the Mancunian Way, for example.
Dr Potgieter-Vermaak says: “What we have observed is that NO2 has not decreased to safe levels in all areas.
“This is actually unsurprising as although we know that one of the main sources of urban nitrogen oxide pollution is transport, we also know that other sources, such as industry, residential and commercial gas and oil combustion, and urban geography, play a part.”
Dr David Megson, Senior Lecturer in Chemistry and Environmental Forensics, says the lockdown has given scientists a chance to learn about the importance of different sources of air pollution, including contributions of nonvehicle sources.
“This new information could have a direct impact in saving lives in the future and reducing deaths directly linked to poor air quality in our region as we can use this insight to implement more effective strategies to the improvement of air quality,” he says.
“I believe we can do this thanks to the high quality data produced by our air quality monitoring network and by working closely with our project partners, public bodies and policy makers.”
In 2019, it was reported that air pollution was costing the regional economy up to £1bn annually and it is believed that more than 100 people die every year from toxic air in the city, MMU says.