In their second column for the CNJ, the Camden Clear Air Initiative – which has installed sensors around the borough – give us a ru down on what caused spikes in air pollution over the wintry holiday season

DESPITE the Met Office confirming that 2022 was the warmest year ever, the past couple of months have felt exceptionally cold. The first two weeks of December were the coldest start to winter since 2010, and January has also seen freezing temperatures. But what effect do these freezing temperatures have on air pollution in Camden?

Thanks to AirScape air quality sensors we can find out. AirScape’s PM2.5 data shows a great increase – more than 200 per cent – in PM (particulate matter) concentration in December compared to earlier months.

The increase in PM concentration is more visible in the first half of December, especially between December 9 and 17 when average temperatures oscillated around zero degrees.

The PM2.5 pollution in that period was on average four times higher than the average pollution of the previous two months – October and November.

There could be many reasons for this increase in PM2.5 over the winter period, but a likely cause could be an increase in people using wood burners or other ways of increasing temperature in residential areas.

The main pollutant emitted by burning solid fuels like wood is ultra-fine particulate matter, also known as PM2.5. It’s not visible to the naked eye, so even “smokeless” fuels and appliances may be causing pollution.

The high concentration of PM can be further explained by low precipitation and low wind speed during that period, which would enhance the polluting effect of local sources. Another interesting spike in PM2.5 can be seen on New Year’s Eve.

Some AirNodes observed very high PM2.5 concentrations (over 100 ug/m3) around midnight and this could probably be explained with private firework parties that happened to take place in close proximity to a particular AirNode.

Moreover, 30 minutes after midnight most of the AirNodes in Camden observed a four to five times increase of PM2.5 concentration from the baseline that lasted for around 30 minutes and can likely be attributed to the plume of fireworks pollution slowly dispersing over London.

What impact can this have on health? PM2.5 is widely acknowledged as being the air pollutant which has the greatest impact on our health and current evidence suggests there is no safe level of PM2.5.

Exposure to PM2.5 increases the risk of early deaths due to respiratory and cardiovascular diseases; and children growing up exposed to PM2.5 are more likely to have reduced lung function and can develop asthma.

It is important that we respond to this data and learn how to reduce air pollution and protect ourselves from it. So what can you do?

Check AirScape.ai at any time of the day to see real-time air quality data on your street or on your journey to work or school. You can use this data to better educate yourself on pollution and change your behaviour to have less of an impact but also protect yourself from it, such as choosing safer roads to walk or cycle on and making greener choices.

You can also contact info@camdencleanair.org if you have any questions or would like more advice on air quality.

Georgina McGivern is programme manager at Camden Clean Air https://camdencleanair.org/