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