Document 71z9Emxe8vg5188X6DGG2RMdj

THE EVENING STAR VninrlM, 0. C. A9 s*wr. occ. it, im - _ Pesticides Reduce sease, Scientists' Say By JOIIN UVNNAN ` humans PCBs cause a special units where all three groups of . SterSUH Writer form of acne, a skin eruption. PCB-fed fowl and one of the con-j Scientists at the University of In birds, both PCBs and DDT trol groups were injected with-1 Wisconsin have reported for the interfere with the production of duck hepatitis virus. The re-} first-time that so-called "hard estradiol, a hormone that con maining "control" group got no.- pesticide" materials apparently trols egg formation. Tlieir effect virus. reduce resistance to and raise is thought to be ultra-thin egg Death began among the: death rates from viral disease. shells which break, tlms endan PCB-treatcd ducks I to 16 hours Dr. Milton Friend of the De partment of Veterinary Science gering the perpetuation species of birds. of whole ahead How of the untreated group. much PCB the birds had said in a telephone interview: Reason For Selection consumed appeared to make no "This is the first time that difference in their ability to' some of the things that people Dr. Friend said mallards were fight off the infection or when have been saying about these chosen because they are ``well they succumbed to it, the report materials have been demon understood, ubiquitous and con said. .r strated in the laboratory." - He and Dr. Daniel 0. Trainer made their report in the current issue-of Science magazine. They said that 10-day-old mal lard ducklings fed "sub-lethal fronted with similar ecological insult..." The researchers are continu ing their experiments with other disease-causing organisms "to determine whether any interac tion, antagonistic or synergistic, "The suggestions that PCB- may render a host more susccp- tible to certain types of infec tious agents is the significant finding of this study," the re-, searchers concluded. ( doses" of a chlorinated hydro occurs. . ." Influenced Mortality j carbon called "PCB" suffered four times the death rale of ducks who ate no PCBs before being infected with duck hepati tis virus. Gose Chemical Kin Dr. Friend and his co-workers used five groups of ducks, 23 ducklings to a group. Three groups were fed diets containing 25, 50 and 100 parts of PCB per million for 10 days. Two groups of ducklings got "None of the concentrations of. PCB fed resulted in detectable forms chemical intoxication even with the physical stresses of weighing, handling, confine ment and crowding... - PCBs, technically, polychlori no PCBs. "However, when the stress of nated bi-phenyls, are such close No birds got sick or died dur an infectious agent was added, chemical relatives of DDT and ing the experiment though those these sublcthal concentrations its breakdown product, DDE, on the 100 ppm diet "were no (of PCBs) appeared to influence that they are virtually indistin ticeably hypercxcilable" after the resulting mortality rates guishable. ' three days. causing two to four-fold inc Though PCBs had been around All the birds eating PCBs bad reases ... and reduced incu-j in the form of industrial prod significantly higher body balion time." I ucts since the 1930s, they did not weights, the researchers report The same sort of effects were- come to light as a. major--and ed, the heaviest being those get observed in similar experi totally unexpected--environ ting the most PCB. ments invlving DDT and dield- mental pollutant until 1906 when The researchers had no imme rin, Dr. Friend said. they blocked chemists* attempts diate theory as to why. to find and identify DDT. ' Both are now considered to be Birds Isolated These results have not yet been published but the increased death rates ranged from three to; ubiquitous throughout the envi The diets were halted after 10 nine-fold when 30-day-old mal-` ronment and one is considered days and on the 12th day all the lards were fed subleUui doses of' to be as bad as the other. In birds were moved to isolation DDT and dicldrin. . .- t t i DSW 282630 STLCOPCB4063959