ABOUT 155m people around the world have asthma, according to the
Global Initiative for Asthma, and the number is rising. In
Britain, for example, research carried out at Dundee University
suggests that 6% of the population suffers from the disease, and
that the total cost of medical care, drugs and lost work comes
to around £50 billion ($80m) a year.  Although atmospheric
pollutants, such as ozone, sulphur dioxide and nitrogen oxides,
do not cause asthma, they certainly aggravate it. Another
susceptible minority are those who suffer from allergic
rhinitis, better known as hay fever. These unfortunates are
sensitive to biological “pollution”, particularly pollen and
spores. In Britain, the main cause of hay fever is grass pollen.
In Japan, the culprit is cedar pollen. In Spain, pollens from
olive trees and ragweed are to blame.  The lives of both asthma
and allergic-rhinitis sufferers could be improved enormously by
reliable forecasting of the levels of these pollutants. It would
mean, for example, that suffer