What can Open data tell us about the air we are breathing?

What can Open data tell us about the air we are breathing?

Bristolians who worry about the air they are breathing whilst running or cycling can now discover the facts, thanks to open data. People can find out when the best times to go are and when pollution levels are at their lowest. Better still, open data can tell you what exactly you are breathing in right now, and what you have been breathing so far.

So, what is open data? Far from being the geeky concept it might sound like, when it comes to measuring air quality, open data is literally transforming our lives, enabling us to fight against air pollution thanks to a better understanding of our current situation.

Reassuringly, open data suggests that Bristol’s air quality is not as bad as the city’s congestion and traffic might suggest. Indeed, the Historical Air Pollution Index Data from the Department for Environment, Food and Rural Affairs shows that air pollution has been reasonably low so far in 2015. As of October 20th there have been 281 days out of 293 characterised by a low concentration of pollutants in the air. The index, determined by the highest concentration of four pollutants (ozone, nitrogen dioxide, sulphur dioxide and particles), shows that in the past year, the pollution levels in Bristol were rated as “moderate” on ten days, while on just two days did the air pollution in the city reach “high”. Coupled with this year’s impressively low pollution levels, Bristolians have good reasons to be optimistic given that in 2014, 349 days of the year were rated “low” for pollutants.

But these are just numbers – what exactly is air quality open data telling Bristol’s citizens? Mainly that for the majority of the time Bristolians are free to enjoy their usual outdoor activities (weather permitting, of course!). According to the Committee on the Medical Effects of Air Pollutants’ Code of Conduct, the city’s population should not be changing its habits any time soon. Nevertheless, on the rare days when the concentration of carbon monoxide, ozone, nitrogen dioxide and sulphur dioxide increases in the atmosphere, people should consider slightly reducing their outdoor physical activity, especially those who are affected by lung or heart problems. Despite the good quality of Bristol’s air, a small alarm bell should be ringing. According to live data from plumelabs.com, an urban weather forecaster, Bristol’s air is slightly above the yearly World Health Organisation recommendation 230 days per year.

In particular, as with almost every other city in the UK, some concerns remain on the levels of nitrogen oxides (NOx) in the air. Mainly produced by burnt fossil fuels, these toxic gases are caused by diesel vehicles and, more generally, traffic. Indeed, despite the fall in the concentration level of both gases since November 2014, recent data from five key monitoring stations of the Bristol City Council shows that the level of nitrogen dioxide (NO2) in the air is still beyond the European Union legal limit, set at the annual average of 40 micrograms per cubic metre.

Whilst that might sound scary, the Department for Environment, Food and Rural Affairs predicts that the city is on-track to meet EU regulations on air pollution between 2020 and 2025. And while Bristol’s residents don’t need to give up running on the Downs or cycling through the city just yet, it’s clear that a better collective effort needs to take place to pursue cleaner air.
Simone Grassi, Bristol Is Open

Historical Air Pollution Index Data, Department of Environment, Food and Rural Affairs
What is the Daily Air Quality Index?
Medical Effects of Air Pollutantants Code of Conduct

Photo credit: Image of Fog Bridge, part of Bristol European Green Capital. Image taken by V. Grace