The initial intention behind this blog was to send out data from our node regularly so our community could know what the air quality was like, and what to do about it. We have finally got the node up and running (albeit in a different place to what we intended) and are excited to be looking at some local data!
A quick way of getting an idea about air quality is to look at the number of days where the daily WHO guidelines are breached. For PM2.5 this means above 15 ug/m3, and for NO2, above 25 ug/m3. Over the past nine days there have been no days where the PM2.5 concentration is above the WHO guidelines, but on all but one day the NO2 concentration has been above WHO guidelines. Interestingly, the PM2.5 averages are considerably under the WHO threshold, but the NO2 averages are way over threshold. Comparing hourly data from the node to the average readings across all Breathe London nodes shows that PM2.5 levels are generally lower than average, and NO2 levels are generally higher than average.
This is slightly puzzling: the node sits near a busy intersection between St Matthew's Road and Brixton Hill with lots of vehicle traffic. Contributing factors to air pollution include imported pollution, and for PM2.5 this effect is greater, which might give rise to lower levels. But we’ll be keeping an eye to make sure the node is correctly calibrated and giving reliable data.
WHO do you believe?
The big question is, what effect does this have on health? Well, it depends who you listen to, or rather, whether you listen to WHO. While the Brixton NO2 levels are significantly higher than the WHO guidelines, they still only score as Low on the UK's Daily Air Quality Index (DAQI). This is because the WHO guideline is not even halfway along the lowest low band. The WHO estimates that for a day where NO2 levels are at 25 ug/m3, this represents an excess morbidity of 2.1%. while the UK merely advises us to Enjoy your usual outdoor activities.
It feels like it is time for the DAQI bands to be reviewed.
What can you do?
One thing we can all do is support the campaign for a change to the law. The petition to give parliamentary time for the Clean Air (Human Rights) Bill is open and over 10,000 have signed meaning the government will need to respond. If it gets to 100,000 then it must be debated in parliament. The Bill is also known as Ella’s Law after Ella Adoo Kissi Debrah who died in 2013 at the age of nine as a result of asthma contributed to by exposure to excessive air pollution in London. The Bill would put the right to clean air in law and ensure public bodies act to meet WHO guidelines. Please help to get it made law!
Ah congrats on getting your node up! I see you are not wasting any time digging into the data, great analysis thus far.