Imperial Valley press., 1945-08-20
Expert Explains
Use Of DDT,
New Insecficide
BY JACK ROWLES

NEW OLeIN, TuS. ~. VIZ
(HFR R)-Wars end quickenod the
chemical incustry's plans Monday
for mass distribution of DDT, the
worlds most effective insect killer,
but medical experts warned that it
must be used cautiously.
DR.. Paul A. Neal, senior surgeon
of the industrial hygiene research
laboratory, national institute Of
health. found that careless handling
of DOT residues-that part of a
DOT spray which remains when the
liquid carrying agent has evapor-
ated-may cause toxic effects in
1 humans.
is TASTELESS POWDER
DDT is a taSteleSS white powC cr.
When it is dissolved in liquids to
make a spray. it assumes a COM
mercial name of the manufacturer
choice. Geigy e. Co., Inc, holders
of the use patent on DDT, calls its
DDT-cCntaining spray "Neocid"
Other such commercial names will
become household words in the Un-
tied States.
Neal pointed out in his report,
''DDT Toxicity," that DDT bears
a physical resemblance to flour
and therefore 1t must not be
stored alongside food suppnes.
He said that 'ingeStiCn eating Of
massive doses of DOT will be toxic
poisonous. p.
DDT, Neal said should be used
under conditions which exclude
the heavy contamination of food.
This means caution in spraying the
new insecticide literally in kitch-
ems or other fCoC storage place in
the house.
NORMAL USE
Neal pointed out that normal use
of DOT sprays is not injurious to
humans. He said contamination of
the skin from such residueS as
produced by the desired insccticidal
concentration CT DDT in air is of
such low order that it will not
cause injurious effects to humans.
In experiments with lower ami
NAL forms. Neal found that DOT.
when dissolved in oily, fatty liquids
for heavy spray, will kill mice.
/ Death is not caused by breathing
the spray, he said, but results when
mice lick their fur which is coated
. with the inSectiCide. Rabbits eX-
posed for 48 minutes daily tC a
heavy mist spray of a DDT mix
ture for four weeks developed no
signs Of DOT poisoning. he said
but suffered irritation Of the mu-
cOus membranes of the eyes. the
upper respiratory tract tlungsl anG
the skin which was CauCed by the
solvent"
The discovery CT a mild solvent.
or carrying agent, for DDT is one
Of the most important CHALLENGES
facing manufacturers of DDT for
civilian use today. In such solvents
as deodorized kerosene. the base
Of such common Insecticides as
Fit, DOT has tendency to irri-
tate the eyes and upper lungs
Geigy is experimenting broadly to
fine a solvent that will eliminate
these effects.
CLINICAL STUDY
Neal reported that in August
1914, "a thorough clinical and lab
oratOry study was made on three
men who each had several months
of continuous exposure to DDT
when used as a mist and dustine
powder fer delousingl. The eX-
posure of these indivic uals to DDI
was extremely great-more so thar
| necessary for the work they werC
| doing . )" Neal said that after
carefully avaluating all the evi-
dcnce we were led to the con
cluSion that none of them pre-
sented definite findings that car
be attributed to the toxic actor
Of DDT."
Danger Neal implied. lies only
in the reckless use Of DOT. The
individual must be the judge in
handling chanictrv'c pcu- hOor