Document yr91BL2nYMmO6jamVmgDzeoa4
Wisconsin State Journal
MADISON, WISC.
D.
SON. 107,031
MAY ,9 1969
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Expert Sdys POT ;
Weakens in Mature
rVAn expert on pesticides and their residues testified at the' state DDT hesrlngs^Thiirsday that in any situation in nature*
DDT will break down and not become a permanent fixture of
the environment.
.
But, according to Dr. Paul E. Porter of lhe.SheU_Develop.: mont Co. and now a visaing sclemhft In England, the periods
of breakdown and loss of DDt:
`"
from various substances has a casei'tf would take 30 to 40 days ' wide range of time periods --I[for thfComplete loss of DDT. 1 j
'two-thirds of it can be gone from The first step hi the break-1
e "live" soil in two weeks or 20j[down of DDT is to form a rela-'
[per cent of it can disappear per lltvc called DDE. This form o! >
[year from soil.
the chemical is less toxic than I
"I know of no natural situa-||DDT.
t
Uon in which DDT Is not de- On reference to its action in!
[graded," Porter said.
soils, Porter said that DDT Is \
tightly bound to soil particles ;
Porter was challenged only1 and not readily moved by water, j
moderately by Viclor J. Yanna- If it is moved, it is by "physical \
cone, attorney for the petition dJslodgement," he said.
ers who want to ban DDT In the] In water, like streams and !
state. At 4he end of less than] lakes, DDT is extremely Jnsphk j
three hours of testimony, Yan. [able and Porter said that it<
necone thanked Porter for com tends to absorb into any organlo \
ing (from England) and never|[matter. Thus it will collect in the ,
did cross-examine the witness. mud (pf a lake) which is high in i
The hearings will resume][organic matter. ^
j
Monday.
HOWEVER, PORTER eontln- < AS FREDRIK WAISS, attor-| ued, its breakdown in mud will i
ney for the National Agricul |be rapid.
tural Chemicals Assn., / ques I As for the breakdown of DDT ]
tioned Porter, the scientist em in fish. Porter said it has been;
jphasized that in many cases the][demonstrated that a degrade-1
build-up of DDT wUI not be in (ion does take place, although in
definite, butwUl reach a pla fish It !e very slow;
j
teau.
Porter was questioned atj
In the atmosphere, DDT is] length on the presence of pies-'
subject to the action of sunlight ticing agents known 11 p and oxygen and Is broken down] thatjnterfcrre with gas chroma-!
tography readings on DDT. This j
Into a less toxic DDE and other was e carry-over from Wednes-.
compounds.
]day't cross-examination of e de-j
Porter added [breakdown In
etihr act othueldDDbTe,,IspianrtmAelunmt hnei eRd efrsoemarc(hhe
Wlscon-! Founds-!
[more rapid than it was on lion (WARF).
*
iglass aurlace, where half of 11 is! Porter said In answer to a
Ijlost in 12 days when in sunlight] question on WARF's capability;
"We have the highest regard for'
WHEN APPLIED to crops, their capability. It is one of the-
Sthe lot* of DDT U accounted for] [' commercial laboratories
by evaporation, the plant meta-l where we have work carried out
Ibollc process, end rain. In thlal for us."
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MONS 029002