Air quality levels and weather trends over the last few months have not reached a threshold that drives me to post, but this has been a strange fortnight.

On the evening of Tuesday 18 June we had a spectacular thunderstorm at the end of an unusually wet and unsettled period. The media widely reported more than 1,000 lightning strikes in the Eastbourne area, and I can vouch for that. There was a serious strike on Hardy Drive.

That came on the back of some very warm and humid weather which broke into clearer and sunny days, like the picture above. Since then we have been enjoying a "sub-Saharan plume" apparently, which has brought record temperatures to France, although we haven't seen the same temperature boost in the UK yet.

The wind blows where it will

In the midst of all this atmospheric activity PM levels have stayed generally low. A few months ago I realised that our experience of atmospheric pollution is largely a macro-environmental phenomenon, operating on a continental scale (where, for example, in February, Parisian air pollution had a very significant impact on air quality in Eastbourne). Localised pollution sources have an effect, especially as you get closer to them, but generally not as strong as.

Being next to a busy road is a bad thing, but not as bad as being in a city, or having the pollution from a city brought to you by the wind. Localised pollution is negative, but it's impact fades away into the background relatively quickly as you move away from it. Living right next to a sewage works run by a company which has struggled to comply with environmental legislation is a problem, but unless the wind is blowing in the wrong direction, most of the rest of the town won't have a problem with it.

Macro/micro

Air pollution is cumulative, so lots of small sources can add up to a large amount. Living in a city frequently results in exposure to high levels of particulate matter because you have lots of sources all around you, and wherever the wind is blowing from it will have passed over pollution sources. However, living in the countryside is not the silver bullet. Winds can bring the atmosphere of the big city into the fields and forests of rural anywhere.

There was a great article I read a while back about how the prevailing wind is generally from the west, which, the author argued, is why the east side of a town or city has historically been the less salubrious part, and the west side the more rarified. If I can find the link I'll post it. [Update It turns out to be not a single article but a well-recognised phenomenon, in London and many other places around the world.]

How you manage your own home and control your exposure to particulate matter pollution matters, especially how close you are to pollution sources for how long, but your neighbour's attitude towards pollution matters for you also, and the conduct of individuals in the rest of your town or city too, even visitors. And cities have a big impact over a far greater area than just what lies within their ring roads. What we do in the privacy of our own home, or in our back garden can add up to a marked effect on the rest of our communities.