14. One in Every Four
THE BATTLE of living things against cancer began so long ago that its origin is lost in
time. But it mus t have begun in a natural environment, in which whateve r life inhabited the
earth was s ubjected, for good or ill, to influe nces that had their origin in s un and s torm and the
ancient nature of the earth. Some of the elements of this environme nt created hazards to
which life had to adjust or perish. The ultraviolet radiation in sunlight could cause malignancy.
So could radiations from certain rocks , or ars enic was hed out of s oil or rocks to contaminate
food or water s upplies. The environment c ontained these hostile elements even before there
was life; yet life arose, and over the millions of years it came to exist in infinite numbers and
endles s variety. Over the eons of unhurried time that is nature’s , life reached an adjus tment
with des tructive forces as s election weeded out the less adaptable and only the mos t res is tant
s urvived. Thes e natural cancer-causing agents are still a factor in producing malignancy;
howeve r, the y are few in number and they belong to that ancient array of forces to which life
has been accus tomed from the beginning.
With the advent of man the situation began to change, for man, alone of all forms of life, can
create cancer-producing substances, which in medical terminology are called carcinogens. A
few ma n- made carcinogens have been part of the envi ronme nt for centuries. An example is
s oot, containing aromatic hydrocarbons. With the dawn of the indus trial era the world became
a place of continuous , ever-accelerating change. Instead of the natural environment there was
rapidly s ubs tituted an artificial one compos ed of new chemical and phys ical agents , many of
the m pos s ess ing powerful capacities for inducing biologic change. Against these carcinogens
which his own activities had created man had no protection, for even as his biological heritage
has evolved s lowly, s o it adapts slowly to ne w conditi ons. As a res ult thes e powerful s ubs tances
could easily penetrate the inadequate defens es of the body.
The his tory of cancer is long, but our rec ognition of the agents that produce it has been s low to
matu re. The firs t awareness that external or environmental agents could produce malignant
change dawned in the mind of a London physician nearly two centuries ago. In 1775 Sir
Percivall Pott declared that the scrotal cancer so common among chimney s weeps mus t be
caus ed by the s oot that accumulated on their bodies. He could not furnis h the ‘proof’ we would
dema n d today, but mode rn res earch methods have now is olated the deadly chemical in s oot
and proved the correctnes s of his perception. Fo r a centu ry o r more after Pot t’s dis covery there
seems to have been little further realization that certain of the chemicals in the human
environment could cause cancer by repeated skin contact, inhalation, or swallowing. True, it
had been noticed that s kin cancer was prevalent among worke rs expos ed to ars enic fumes in
coppe r s melters and tin foundries in Cornwall and Wales. And it was realized tha t work e rs i n
the cobalt mines in Saxony and in the uranium mines at Joachims thal in Bohemia were s ubject
to a dis eas e of the lungs , later identified as cancer. But thes e were phenome na of the pre-
indus trial era, before the flowering of the indus tries whos e products we re to pervade the
environme nt of almos t every living thing.
The first recognition of malignancies traceable to the age of industry came during the last
quarte r of the 19th century. About the time that Pas teur was demons trating the microbial
origin of many infectious diseases, others were discovering the chemical origin of cancer skin