Crash course in radiation - and other airborne risks

I watched this video of a lecture given by physicist Dr Otsuka at Tsukuba university this weekend, who explains some of the science behind the numbers we are seeing. He's a great lecturer, and funny, too!

I have been thinking also for the last week about how we deal psychologically with the risks that we take in our daily lives - driving, crossing the road, taking the plane (especially if you like to travel to places like Indonesia), talking on our mobiles, taking medicine, breathing the polluted air of our cities: all of these could be terrible sources of anxiety if we always had all the risk probabilities in mind. But if I went to the doctor saying that I no longer dared drive because there is a 0.007% chance I might be killed in an accident, I'd be immediately referred to a psychologist for an anxiety disorder. 

Radiation  scares us because it is invisible, Dr Otsuka pointed out in his lecture. But so is another serious health hazard:  air pollution. (Except if you live in Hong Kong, where some days the "haze" is so thick you can't see Kowloon from Central: pollution is definitely visible there.)

What are the morbidity/mortality rates for air pollution? Why do we accept this risk as a necessary price of development, of living in a bustling, rich, exciting city like Hong Kong, Madrid, Shanghai, New York, or Tokyo?

I will have to quote Wikipedia on this - sorry - specifically a WHO report quoted in the footnotes, which estimates annual worldwide mortality from indoor and outdoor air pollution at 2.4 million. To take Switzerland, for example the estimate is 800 deaths annually, for a population of 7 million. Air pollution aggravates respiratory disease, cardiopulmonary disease, asthma... making some people sick and killing others. 

To return to Hong Kong, where we lived for three years, we had many days of "high" pollution according to the totally outdated HK government standards, which would have been considered off the charts in most other countries! The subject is highly controversial in Hong Kong (see summary on Wikipedia), where the attitude seems to be that some increase in mortality  is the  price of prosperity. Have airlines ever cancelled their flights to Hong Kong for fear of exposing their staff to these extreme levels of particulate air pollution as Swiss, Lufthansa and Alitalia have done this week for Tokyo? Of course not.

Another possible difference between our perception of pollution vs radiation as a health risk, is  that no one dies spectacularly of a sudden, high exposure to city air pollution, whereas a sudden high dose of radiation will most definitely kill you. Secondly, that main health risk associated with radiation is cancer, an illness we fear more than others because it is hidden, mysterious, painful and not always treatable.

So while the threat of a radioactive cloud rising from Fukushima and spreading over Japan is scary, it's important to see it in the context of other environmental pollutants as well. Yet another reason to switch to renewable energy sources and work harder to reduce our consumption of energy.