Document 3m428Kd8pD0RZJvKx826mLnJ
piu-itura, m Lranxioniivrx such as
.1 utility poic;<, and a* iH'nt-exI' change tUiLUx in mnnv industrial .
; operation*. The solo maker of li PCS la the U.S. it Monsanto. .
.ii which uses tho trade name
h Aroclor. ' It It generally believed that
V PCB finds its way into the cn-
'.l vironment at tho result of burn-
*1 ing discarded plastics and other .
materials in which they are
r used and through leakage from ,
I, machinery in which liquid PCB Ills used.
,* In July, 1971, for example, t '
'heat exchanger used in the
t, manufacture of a chicken feed
* supplement leaked. ?C3 sot in*
t( to the supplement end, even-
totally* into alt the chickens that ,, ate the feed. Some 77,000 chick-
ens were destroyed to prevent
y. their ranching tho markot.
'
Dr. Albert C Xoibye Jr., deH puty director of tho F.D-A/s
a Bureau of Foods, spoke at the
t Chemical Society meeting and
said that despite the widespread
*| presence of PCB in the environ2 meat, the chemical was not con-
i sldercd now a threat to human
b health.
"I think the problem is un*
[ der control,M he said. "We hew S a wry large margin of safety
for PCB as long as we avoid undue, accidental exposures.** .
Dr. Kolbye said that although I his agency's tests showed that
\ PCB was present in many foods, .
* the levels consumed by the
5 average person were only one
*! tenth as high as the maximum
safe level set by the food and
drug agency--5 parts per mil
t Hon.
*
V Scientists have found that for
I many persistent toxic chemicals,
j ths risk of damage to health
f depends not only on the con esntration of tho chemical at a
given moment but on the length
i of time a person .or animal is
t exposed to ths chemical.
'* The F.D.A. analysis of fish
! showed that of 670 samples
? tested, 94 per cent contained
J PCB in concentrations ranging
x from trace amounts up to 33 parts par million. Eggs, the see- :
J. ond most common source, show-
J ed PCB in 29 per cent of 330 . J samples tested. Cheese and
milk were the least likely (6
? end 7 per cent) of the foods
' tested to contain PCB. although i in one case a milk sample had
a concentration of 27.8 parts
' per million.
.
In another report to the
; Chemical Society, Dr. Anne R.
Yobs, of the Environmental
I Protection Agency's Office of
'* Pesticide Programs, said there was now substantial evidence
4 that many human beings have . ,` acquired levels of PCB in their
tissues. f The tests were done on fatty
- tissue removed from 637 per sons either during surgery or
I at autopsy. The samples came
* from persons from 38 cities in ' 18 states.
u Just over half, $0.7 per cent. * contained measurable levels of : PCB, tho conccntratisns ranging
c from trace levels to 16 parts
per million.
: -UJS. Geological Survey has de-i
;' . teeted varying levels of ?C3 ini '
1 . the weters of New York, Con-.
necticut, Pennsylvania. V:rg:r.:a.1
South Carolina, Florida. Ni.si.s-1
. sippi, Texas. Arkansas and ` California. Tests in other states |
. are expected in 1973.
1
. ^Michigan State University! *
, researchers found that the rca-1
< - son for an almost complete ccs-1 sation of reproduction in mmk
' ranches In the Great Lakes re
gion wss the presence o; ?C3'
in the coho salmon fed to :..c-
mink. A level of 5 parts ptr. ' million of PCB in the w.c:. . caused complcto reproductive
< failure. 1 PCB. which stand, for po!v-|
, chlorinated biphenyl, is ore o..
- ths most widely used industrial i chemicals. Various types o; ?C3:
{ . are used as plasticizers. ad-|
. # * hesives. sealants and prnt.r.g;
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