Document 7M0QbK3NEoeQvX5ejn4Ey499e

Wisconsin State Journal MADISON, WISC. D. 68.775 SUN. 107.031 m ,9 1969 ( ijipert i i, ! 'T-'An expert on.pestiddes and their residues testified at the" state DDT hearings^Thursday 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 the Shell Develop-: ment Co. and now a visiting scientist in England, the periods of breakdown and loss of DDT.-----;--------------;----------------. 'from various substances has a caseidt' would take 30 to 40 days .wide range of time periods -- for thf'complete loss of DDT. two-thirds of it can be gone from The first step in the break a "live" soil in two weeks or 20 down of DDT is to form a rela per pent of it can disappear per tive called DDE. This form of year from soil. . the chemical is less toxic than "I know of no natural situa- DDT. tion 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 j Porter was challenged only and not readily moved by water, i moderately by Victor J. Yanna- If it is moved, it is by "physical i cone, attorney for the petition dislodgement," he said. ers who want to ban DDT in the In water, like streams and , state. At dhe end of less than lakes, DDT is extremely insolih j three hours of testimony, Yan- able and Porter said that it; nacone thanked Porter for com-! tends to absorb into any organic i ing (from England) and never matter. Thus it will collect in the , did cross-examine the witness. mud (of a lake) which is high in The hearings will resume organic matter. ^ -j Monday. HOWEVER, PORTER contin- i AS FREDRIK WAISS, attor ued, its breakdown in mud will! ney for the National Agricul be rapid. '] tural Chemicals Assn., / ques As for the breakdown of DDT; tioned Porter, the scientist em in fish, Porter said it has been phasized that in many cases the demonstrated that a degrada- j i build-up of DDT will not be in tion does take place, although in j definite, but / will reach a pla- fish it is very slow; ; ; teau. Porter was questioned at] j In the atmosphere, DDT is length on the presence of plas- ` : subject to the action of sunlight ticing agents known as PCRsl that jnterferre with gas chroma-*' | and oxygen and is broken down tography readings on DDT. This ] ! into a less toxic DDE and other was a carry-over from Wednes-j I compounds. ; day's cross-examination of a de-'j . i Porter added that the DDT breakdown in air could be more rapid than it was on a glass surface, where half of it is partment head from the Wiscon*' sin Alumni Research Founda-; tion (WARF). i Porter said in answer to a' ! lost in 12 days when in sunlight. question on WARF's capability: "We have the highest regard for' I WHEN APPLIED to crops, their capability. It is one of the; the loss of DDT is accounted for f e w' comipercial laboratories ' by evaporation, the plant meta- where we have work carried out .bolic process, and rain. In this for us." ` DSW 200980 STLCOPCB4059044