Friday, 2 December 2011

A whiff of ozone

The EEA (European Environment Agency) is one of those activist government bureaucracies untainted by any whiff of democratic legitimacy. One of those irritants we have to live with – like ozone.

The EEA says that ozone and particulates in the air we breathe are the most serious air quality problems in Europe. I'll post on particulates another time - here I want to take a very brief look at ozone and get some kind of preliminary handle on the value of this headline.

Environmental issues of interests to activists can be frustratingly difficult to untangle, for scientists and non-scientists alike. As with climate science, uncertainty is often morphed into certainty where funding and political point-scoring are at stake. The vexed question of ozone in the atmosphere is one such issue.

Ozone is a gas, an allotrope of oxygen with three oxygen atoms per molecule instead of two. It is highly reactive with a bleach-like odour. In the stratosphere it absorbs UV radiation from the sun, acting as a shield for life on Earth which would otherwise be harmed by unfiltered UV. In the lower atmosphere it is implicated in human respiratory problems, smog formation and a number of other deleterious effects. 

In spite of the UV being absorbed by ozone in the stratosphere, some does reach the lower atmosphere where it also causes ozone to be generated. Ozone is formed in the lower atmosphere when ultra-violet radiation in sunlight interacts with hydrocarbons and oxides of nitrogen from sources such as vehicle exhausts.

However, personal exposure to ozone and its likely effects are not easy to estimate. For example, anyone working near certain types of electrical equipment such as photocopiers, may well have a significantly elevated exposure to ozone.

Does it matter though? Hard to tell. High concentrations of ozone are likely to be harmful, but as with other respiratory problems, people vary in their response, quite apart from numerous other complicating factors. This plot from the EEA shows ozone levels across the EU.

Notice anything? It must be obvious to scientist and non-scientist alike that the Mediterranean area is a significant factor in elevated lower-atmosphere ozone concentrations. Sunlight is the obvious factor from what we know of ozone generation chemistry, but what does the EEA propose we do about sunlight?

Another interesting question is how this affects the purported health benefits of the Mediterranean diet – all the fish, tomatoes and olive oil? Do people in this area have healthy hearts and unhealthy lungs?  

So what about ozone being one of the most serious air quality problems in Europe? Maybe it is, but ozone in the lower atmosphere seems to be highly variable and strongly linked to latitude where sunlight is presumably strongest. The climate change debacle has to be a warning to us all. Understanding these things requires research beyond the activist headlines - including those published by EU institutions. 

Maybe it’s also a matter of different funding streams each with a different agenda - as these things so often are.


Mark Wadsworth said...

I quite like the smell of photocopiers. As to Mediterranean, we can also balance higher ozone against having more Vitamin D, I suppose. You win some, you lose some.

Sam Vega said...

Ha! The poor bloody Scots get hardly any ozone, which explains now the appalling morbidity and mortality rates. That and the deep-fried whisky, of course...

James Higham said...

one of those activist government bureaucracies untainted by any whiff of democratic legitimacy


A K Haart said...

MW - hmm - when did you first start sniffing photocopiers?

SV - at our latitudes we could get our fair share of ozone from electric cars.

JH - thanks (: