View report page

199
to life and property occasioned by atmospheric pollution which
can be summarised thus:—
(a) An increase in deaths from respiratory and heart diseases
which appears to be proportional to the amount of
impurities and length of exposure.
A normal reaction to the constant inhalation of dust is a low
grade inflammation—the lining of the lung is rtimulated to secrete
mucous in order to remove the soot, dust, ash or other irritant
and this can and often does lead to catarrh and bronchitis. In
addition, fibrosis resulting from irritation impairs the lungs' elasticity
which in turn tends to prevent normal drainage so necessary
with respiratory diseases. Besides radio active particles, atmospheric
dust is known to contain varying quantities of other
carcinogens such as arsenic, benzpyrene and other coal tar products.
In certain circumstances, soot is also considered carcinogenic
and it is easy to see how atmospheric pollution becomes
linked with lung cancer.
(b) Absorption and elimination of ultra-violet rays from
sunshine.
It has been calculated that London has been losing 300 hours
of sunshine per year through fog and smoke and it is a fact that
lung cancer in urban areas is noticeably higher than in rural
areas. It is possible that a connection between cancer deaths and
lack of sunshine could be either that a smoky atmosphere predisposes
to lung cancer or that sunshine is important in its prevention.
Under the influence of ultra-violet rays, the ergosterol of the
skin is stimulated to manufacture vitamin 'D', an essential for
the anabolism of healthy bones and teeth. Deficiency of vitamin
'D' leads to rickets and dental caries.
(c) Vegetation becomes stunted.
It is pertinent to record that the plane tree, which sheds its
bark annually is practically the only tree to have flourished in
the London area outside the public parks. Comparison between
flowers and vegetables grown in towns and those grown in rural
areas is superfluous. Deterioration in herbage must have its indirect
effects upon grazing animals.
(d) Damage to buildings, etc.
Sulphur dioxide appears to be the culprit in this respect. At
York Minster holes more than 9" deep have been discovered as
a result of this form of corrosion, and magnesium sulphate crystals
were found in cracks and fissures 20" from the surface of