Evening star., 1934-10-30
Minute Quantities of Rare
Element, SeIenium, Found
by Chemist.
AREAS ARE DISCOVERED
THROUGHOUT SIX STATES
DR.. Henry G. Knight of Agricul.
ture Department Sees Danger
to Man and Stock.
BY THOMAS r. HENRY.


Tentative recommendations that
more than $4,000 acres in the Middle
West be closed to farming or stock
grazing because everything that grows
upon them is dangerously poisoned by
absorbing from the soil minute GUAM
titles OF the extremely rare element.
selenium, or moon metal" have been
made by the Bureau of Chemistry
and Soils of the Department of Aeri.
culture. 1t was announced today be.
fore the Association of Oficial Aert-
cultural Chemists by DR.. Henry q.
Knight of the Federal department.
The poison areas" are spread
through six States. Investigation In
being pushed TO find others. It is
believed that they are distributed
through the semi-arid Wheat-growine
section of the country and probably
all over the world, since toxic amounts
OF selenlum have been found in i'm.
ported wheat.
hhiH 10 sulphur.
Ihe minute quantities of selenium
Closely akin to sulphur. but with
OUT the same physiological properties
are taken up by practically all kinds
OF vegetation, the Bureau of Chemis-
trys tests show. This then poisons
grazing stock or, if on arabic land
people who eat the grain. Fortunate,
y all the selenium land in the United
states Is semi-marginal so that little
gram Is grown upon it and there are
only Two or three authentic records
VI sucn poisoning in human beings
Ut. Knight pointed TO the possibiI-
lty that some of the great Irrigation
projects may contain some "noison
iano' and urged that this be taken
INTO consideration in adopting anv
irrigation plans in the future. SeIen.
iuln IN TOXIC quantities apparently is
confned to dry land of a certain
chemical composition. It does NOT
run continuously over a large area
put is very 'patchy," he reveaIeS
1here Is apparently little to be dona
aoout II except throw the land out of
use. Ihis may become a world prob
,em OF considerable Importance. Or.
knight said.
AS early as 1856. he said. an Arnv
physician noticed a curious Condition
OF i've stock in the semi-arid country
Wnlcn he attributed to the intense
alKall nature of the soil and caIIed
alKan osease." The explanation waS
accepted until few years ago. when
chemlSts at the South Dakota Aeri.
cultural College noticed that il an
peareo TO have curious Distribution
IN certain areas. which could hardly
pe explained by comparative alkalinity.
Inc cooperative research started be.
tween South Dakota and the Depart.
menu OF Agriculture at that time re-
VeaIed the real situation.
Selenium Amount Shown.
Chemical analysis of the soil showed
lne unusual amount of selenium-of
"inch there is bare trace in most
soils-Was the outstanding abnormal
lty. Experiments were undertaken
WIN rats, guinea pigs and hogs here
ana 1t was found that selenium was
poisonous both when fed as an inor-
ganlc compound or when plants grown
on selen1um-impregnated soil were
grown. With heavy concentration
death resulted very soon. With 9TH
ers there was serious interference u,i+h
growth and development. The ami
mas showed the usual symptoms of
aikah disease"-increasing weakness
emaclatlon and fantastic growth of
the hoofs and claws. 1t was espe-
cially toxic to young animals.
Wnen wheat grown on selenium soil
was fed to animals 1t was found that
minute amounts found their vav IN
all body tissues with especial co,,ce,
tration in the liver. 1t was distribI1tad
by the blood stream, From two to
three milligrams per pound of hodv
weight was found lethal. The depart
menu chemists found great differences
IN the amount of absorption by diff
ierent kinds OF plants. Certain grasses
long grown in the selenium country
showed only two parts per million.
which was nov enough to cause anv
Damage. On the other hand a wild
Vetch OF the locality takes up 1850
parts per million. Wheat took up about
10 parts per million. Some plants
TOOK up as much as 5000 parts per
million and probably extensive feeding
on them would be fatal to any animal.
1t has been impossible to determine
tne organic compounds into which
the selenium enters which cause the
damage. Curiously enough, when sui
phur Is mixed with the soil tie abb
sorption of selenium decreases.
Little Loss Seen.
There will be little loss, DR.. knight
indicated, in removing all selenium
land from cultivation Already many
grazing areas have been voluntarily
| abandoned by ranchers without know
ing the reason for the strange malady
which was affecting their sheep and
| cattle. The great seriousness of the
| problem, DR.. Knight said. lies in the
fact that some of the greatest wheat
| areas of the world are on semi-arid
land Of the type in which seleniup
was found in toxic quantities. The
department, DR.. Knight said, is work.
ing as unostentatiously as possible to
get the selenium land out of use and
Is not yet prepared to release the def
mite areas for uhinh raroy,o N, ~, "A a tinv,m