Avertive Behaviour

Yesterday's copy of the Guardian had a particularly interesting piece on the ways in which individuals might diminish the dose of air polution that they receive, short of moving to a less polluted area. The article contained ten simple measures compiled by Dr. Roy Colville, a senior lecturer in air pollution at Imperial College London. The main text of the article can be found by clicking here but briefly the measures advocated include changing the routes that one takes preferring back streets to major urban arteries and avoiding pollution spikes particularly when exercising. One can also purchase a smog mask or fit indoor air purifiers (it seems that the air inside our homes is much dirtier than the air outside). I would guess that many people are already engaged in this kind of averting behaviour.

I found this article interesting because it emphasises once again that the risk from ambient levels of air pollution is partly determined by the individual him or herself. This perspective is somewhat different to the mechanistic dose response function approach so favoured by epidemiologists. Using the dose response approach the observed number of health incidents associated with a given ambient concentration is multiplied by the value per adverse health outcome e.g. the cost of a respiratory hospital admission. But when people exhibit avertive behaviour this approach provides only a lower bound on the benefits from reducing air pollution. The costs of time and money spent reducing risks should also be included.