The Chemical World This Week

INDUSTRY'S PROBLEMS WITH CANCER AIRED The dangers associated with worker exposure to chemical carcinogens have been well documented in re­cent years. But workers are not the only people at risk from these sub­stances. Findings presented last week at*a Conference on Occupa­tional Carcinogenesis, sponsored by the New York Academy of Sciences, indicate that the hazards of the work place are spreading to families of the workers into the general popu­lation. Also presented at the con­ference were data from further studies of known chemical occupa­tional carcinogens, such as arsenic, aromatic amines, asbestos, benzi­dine, and vinyl chloride.

Dr. Henry A. Anderson of the Mt. Sinai School of Medicine in New York City told the more than 600 people in attendance at the confer­ence that wives and others in close contact with asbestos workers also risk developing asbestos-caused lung cancer. He reported that x-ray studies of the families of 354 asbes­tos workers showed that 35% have lung abnormalities comparable to those found in men actually exposed to asbestos. Dr. Thomas H. Corvett of the University of Michigan Medi­cal Center reported an unusually high incidence of both spontaneous abortions and birth of defective children among nurse anesthesiolo­gists who are constantly exposed to low quantities of volatile chemicals, including halogenated hydrocar­bons.

Last November chloroprene was reported by Du Pont as a possible occupational carcinogen. Du Pont's report to the National Institute of Occupational Safety & Health cited two studies by scientists in the U.S.S.R. that found high rates of skin and lung cancer among workers who handled chloroprene and its derivatives. NIOSH's Dr. William Lloyd told the conference that al­though it was tempting to accept the Soviet findings immediately as pointing to a very serious problem, he hesitated to "cry wolf" since a number of factors were not ac­counted for in the report of the Soviet results. These factors include lack of a breakdown on the amount and duration of exposure, data on other chemicals the workers might have been exposed to, workers' smoking habits, and a breakdown of the workers by age and sex.

Nevertheless, he said that NIOSH

is taking the report seriously and outlined the steps that have been taken to either verify or to disprove the study. First off, Du Pont has initiated detailed mortality studies of all its chloroprene workers, with assistance from NIOSH in tracing the workers and determining their present status. Second, the Nor­wegians, who have a chloroprene plant that has been in continuous operation for 30 years, have indi­cated that they are initiating a comprehensive epidemiological study of their exposed workers. Third, the National Cancer Insti­tute is including chloroprene in its carcinogen bioassay program, and Du Pont is initiating long-term ani­mal studies. And fourth, three Du Pont scientists are now in the

NAS's Handler pans 1S The experiment that led to the ban­ning of cyclamates in 1969 was badly designed, inconclusive, and should not have warranted any action at that time, Dr. Philip Handler, president of the National Academy of Sciences, said last week at an academy forum on sweeteners. In October 1969, a National Acade­my of Sciences-National Research Council ad hoc committee, after evaluating the results of a two-year toxicity study in rats, recommended that the Food & Drug Administra­tion ban the artificial sweetener. In the study, rats—fed with either a mixture of sodium cyciamate and sodium saccharin (10:1) or the mixture plus cyclohexylamine (con­version product of cyciamate)—had developed bladder cancer.

Dr. Handler's remarks echo those of Dr. Michael Sveda, inventor of cyclamates, who for six years has been protesting the FDA ban and questioning the validity of the study. At a press conference held the day before the NAS forum Sveda again talked about the haste with which the NAS-NRC commit­tee arrived at its decision and the secrecy surrounding the transmittal of the committee recommendation to FDA.

Last week's forum was aimed primarily at public exploration of a recent NAS report on the risks and benefits of saccharin. Although the report already has been transmitted to FDA (C&EN, Jan. 20, page 19),

U.S.S.R. to obtain details of the Soviet study. But it will be several months, at least, before the actual cancer-causing potential of chloro­prene is determined.

Also reported at the conference were Japanese findings of cancer among benzyl chloride workers. A preliminary study found three cases of lung cancer and one maxillary malignant lymphoma in 147 per­sons who worked in a benzyl chloride plant from 1953 to 1973. And NIOSH confirmed that it had discovered spontaneous formation of bis-chloromethyl ether, from the reaction of formaldehyde and hydro­chloric acid, in some textile plants. NIOSH says it is now investigating the extent of possible worker expo­sure to the carcinogen. D

cyciamate ban

Handler: experiment was badly designed

a summary of last week's discus­sions will be incorporated into the report. And according to Handler, this forum serves as a "model for future instances in which, oc­casionally, preliminary drafts of reports by committees of the Na­tional Research Council will be sub­jected to comment and criticism by informed individuals broadly representative of the public interests prior to submission of the final re­ports to sponsoring federal agen­cies."

The academy's open meeting came 10 days after FDA had of­ficially disclosed that it was recon-

4 C&EN March 31, 1975

sidering the ban on cyclamates. Dr. Alexander M. Schmidt, tjie FDA commissioner, declined to partici­pate in the forum at the last minute, saying that because of an expected regulatory decision concerning cy­clamates in the near future he didn't want "to be influenced in any way by the forum."

Earlier, Schmidt had sent a letter to Abbott Laboratories, which wants cyclamate returned to the market place, telling the company that it would no longer have to con­duct additional testing on the sweetener. And he has asked the National Cancer Institute to make recommendations on Abbott's re­quest based on a study of currently available data. D

Drug may help fight alcoholic hepatitis A new treatment for alcoholic hepatitis, the inflammation and cell death that takes place in the liver as a result of habitually heavy con­sumption of alcohol, appears prom­ising, at least in animals, according to researchers at the University of Toronto.

Last week pharmacologist Yedy Israel and physician Harold Kalant told reporters at a Toronto news conference that a well-known anti­thyroid drug, propylthiouracil, has been used successfully in rats to check the progress of experimentally produced alcoholic hepatitis. In humans, alcoholic hepatitis is the precursor of cirrhosis of the liver, the permanent scarring and mal­function that can lead to death.

The Canadian researchers base their treatment on the theory that alcoholic hepatitis results from a hypermetabolic state in the liver where cells require increased oxygen supply. Liver cells farthest from blood—and oxygen—supplying arteries thus would be vulnerable to oxygen starvation and death.

Increased oxygen demand by liver cells, say the researchers, is similar to the effects that excessive doses of thyroid hormones have on the liver. They also believe that thyroid hor­mones regulate the effects of alcohol on liver cells. Propylthiouracil, on the other hand, reduces the efficacy of the body's naturally produced thyroid hormone supply, and mitigates the actions of alcohol on the liver. When this drug was ad­ministered to rats fed an alcohol-laced diet, abnormal oxygen uptake by the liver and liver damage were reduced.

Clinical trials with selected pa­

tients are under way in Toronto, following more than 12 years of animal studies. But Dr. Israel cautions that widespread use of propylthiouracil for the treatment of alcoholic hepatitis is still years away. In addition, he points out that the drug is only a treatment and "not a cure" for alcoholic cirrhosis. At best it can only "save what's left of the liver, ' ' he notes. D

Another blow to dying rayon fiber business Rayon filament, a venerable syn­thetic fiber and one which helped launch the synthetic fiber industry in the U.S., is sinking fast. The fiber, a largely industrial product with its main use in tire cord, re­ceived another big setback this week as American Enka, part of Akzona, began closing its last rayon filament operation at Enka, N.C.

This plant has run for 46 years and was the company's first manu­facturing operation. The closing comes after an extended decline in operations, during which the plant ran well under its rated capacity of 60 million lb per year. The plant's work force also shrank to 1700 from a peak of 2500.

Despite the work force decline, 1700 is still a big group. Most will be laid off over the next several weeks. The company has set up a special task force to coordinate placement of these people at Enka and other employers.

The plant shutdown represents a distinct reversal for American Enka. Up till now, the company had hoped to keep this filament operation running indefinitely. In fact, plant modernization efforts had been under way since last fall. The company says that good prog­ress had been made in improving production efficiency.

Current business conditions, how­ever, have been too much. The rayon filament operation has been hit from two sides—increased costs in raw materials and energy on one hand and a steep sales decline on the other. This combination simply priced rayon filament out of the market, the company says. The financial impact of the situation was a pretax loss of $4 million last year and running losses of $900,000 per month so far this year. In addi­tion, the company faced spending $8 million to $10 million in the next two years to complets a pollution control program.

Closing the plant will cost the company an estimated $10.5 mil-

Ramsey; other fibers are picking up

lion pretax. This cost will result in an after-tax charge to first-quarter earnings of about 40 cents per share.

Still, » the move will strengthen American Enka's financial position by an estimated $20 million over the next two years. And the shutdown is occurring at a time when Ameri­can Enka's other fiber operations have begun to pick up. Akzona chairman Claude Ramsey told stockholders at the company's an­nual meeting earlier this month that demand has picked up in March. If this trend continues, more normal production should re­sult in most fibers in the second quarter.

Until just recently, the com­pany's strategy in rayon filament was to cut back operations to a single plant at Enka but stay in the business. By the end of last year, the company closed its other rayon filament operation at Lowland, Tenn. Part of the Lowland plant is being converted to production of rayon staple (used mostly in apparel and household furnishings) with startup targeted for mid-1976.

Enka had held onto its rayon filament capacity after several plant closings in recent years by other producers. Last July, FMC shut down its oldest filament plant at Parkersburg, W.Va., in part be­cause of the recession. FMC had closed another filament plant at Lewistown, Pa., in June 1972, after a disastrous flood. In fourth-quarter 1972, American Cyanamid discon­tinued its rayon filament produc­tion at Painesville, Ohio. In 1971, Beaunit Corp., subsidiary of El Paso Co., cut back rayon filament production to one plant at Eliza-bet hton, Tenn.

Overall market figures show the painful reasons for these shutdowns.

March 31, 1975 C&EN 5