Document gE4eEwBgbMDZQMbNMRyRo0nQ

t Medical News January IS. 1900 Experts cite paralysis of asbestos * a#: :x ::jcy **a*?. -uss r* -* S9 U9 *3 Ml 9 `CM Sonar r.i3? i:-v i rnr.nnnnis , exposure control efforts 0=rne hears that considerable trouble is now taken to prevent the inhalation of asbestos dust, so therefore the disease is not likely to appear is the future." So proclaimed a British public health official in 1906 concerning the major health problem posed by the r.eogiing British asbestos industry. Since that time, in the United States alone, 30 million tons of asbestos, "the wondrous mistral fiber with the strength of steel," has been nonetheless employed is many products. The mult? A public health disaster of unprecedented dimensions (JAMA >eaiCAL news] 239:2215*2216.1978), Experts in the study of asbestos*related disease-- asbestosis, lung eancer, and mesothelioma--now esti mate that during the next 40 ye*rs, an average of 20.000 deaths per year will result from asbestos exposure. In the period between World War II (when asbestos use first became widespread) and the end of this century, well over half a million Americana will have died of asbestos-related disease, according to Irving J. Selikoff, MO, director of the Environmental Sciences Laboratory at the Mount Sinai School of Medicine in New York. What is being done to prevent slow deaths caused by asbestos inhalation? Who is examining the 10 million workers estimated to have been exposed to the substaaee on their jobs sinee WWII? Who will accept responsibility for containing the mountain of asbestos now in place? The answers are nothing and no one. Aside from meager attempts to regulate new asbestos use and to monitor occupational exposure, virtually nothing Is being done to remedy the publie health failure and turn back the legacy of death from asbestos. What is worse. 700,000 tons of asbestos is still used annually in the United States to make products such as cement pipe, brake linings, asbestos paper prod ucts. and textiles. Virtually no precautions other than a maximum exposure standard for workers that some consider unacceptably high are being taken to prevent asbestos*related disease. "Unless we learn the lessons of the past." predicts Selikoff, **we are destined to compound the deadly legacy of asbestos and start the dock ticking for the next 40 years." Asbestos is an extremely useful fibrous mineral. The two commercially used varieties, serpentine and amphiboie asbestos, art strong and durable with insulating qualities beyond comparison. But the min utely fibrous nature of asbestos that makes it so useful also makes it deadly. While asbestos fibers are visible to the naked eye, the component fibrils can be detected only with the electron microscope. In the lung, eellular-mineral contact results in interaction between the fibril surfaces and intracellular, perhaps even intranudear, components of cells. Although the pathogenic mecha nism remains unclear, these interactions result in a fibrotie reaction (asbestosis), lung cancer, or both. Therapy of Asbestos Diseases There is no truly effective treatment for any of the asbestos-related diseases, which include asbestosis, mesothelioma, cancer of the lung, and some cancers of the esophagus, stomach, or colon-rectum (Selikoff U, Hammond EC, Seidman H: Mortality experiences of insulation workers. United States and Canada. 1943* 1977. In Health Hazards of Asbestos Exposure [inter national conference). Ann NY Acad Set 33&91-116, 1979). A long latency period (25 to 30 years in most eases), difficulty in diagnosis, and the lack of any widely applied long-term surveillance mechanism all spell a grim outcome for the asbestos-exposed popula tion. Although the malignant neoplasms mult Is higher mortality, asbestosis--a fibrous scarring of the lung that causes diminished pulmonary function--is the most common asbestos-related disease. Such pulmo nary fibrosis is irreversible. Current treatment con sists only of ending further exposure and administer ing oxygen in the case of breathing difficulty. According to Anthony Bobbine, MD, director of the National Institute of Occupational Safety and Health (NIOSH), asbestosis patients, because of diminished pulmonary reserves, "should be treated very aggres sively with antibioties" if My respiratory tract infection such as bronchitis develops. Lung eancer is the most common asbestos-induced cancer and is made worse by the accompanying lung fibrosis. Alvin Tierstein, MD, director of the Pulmo nary Service at Mount Sinai and an expert on treating asbestos-related disease, calls diagnosis of lung ean cer in these eases "a hell of a job" because the fibrosis obscures the radiological findings. Mesothelioma is a malignant tumor of the pleura and peritoneum. Known as a "signal" neoplasm because it almost never occurs except in cases of asbestos exposure, mesothelioma is thought to occur continued on next page JAM* DOW 06775 Madical Nawi inssfinriH continuedfrom prtvious page it much lower exposure levels than are known to cause asbestos!* This U evidenced by the high incidence 0/ the disease among family members of asbestos workers. While Seiikoff and Tientsin are pessimistic about treating mesothelioma, Philippe Chahinian, MD, assistant professor in the Department of Neoplastic Diseases at Mount Sinai, says that the situation Is not desperate.'* Currently at Mount Sinai, investigators are work* ing with two treatment protocols, he says. The first is s combination of doxorubicin hydrochloride and radiotherapy of the hemithorsx. In 14 patienta the median survival has been 12 months. The second protocol combines doxorubicin hydro chloride and azothymidine without radiotherapy. In 40 patients the median survival has been 21 months from diagnosis. Chahinias describes these results as very encouraging compared with the past. "Mesothelioma is as insidious disease." he told JAMA medical news. "There is often a delay between symptoms and diagnosis because patients have only a small amount of pain, not enough for them to seek medical care." While evidence of the disease does tun up os x-ray films, it is difficult to diagnose and has often progressed beyond the aid of surgery by the time of diagnosis. In some eases, according to Tierstein, benign dis ease, resulting is a thickening of the pleura, is detected, la these eases, a pleureetomy can sometimes be performed although this is extremely difficult. One faetor that cao add immensely to the risk of development of lung cancer among asbestos-exposed workers is dgarette smoking, as SelikolTs work has shown. In one Mount Sinai study eohort, asbestos workers who smoked had a risk of lung cancer up to 90 times that of persona who neither smoked nor worked with asbestos and up to 30 times that of nonsmoking asbestos workers. "Anyone with even the slightest suspicion of asbes tos exposure should absolutely be convinced not to smoke," says Seiikoff. In as extensive interview with JAMA medical news, Seiikoff, who it considered by many to be the world's foremost expert on environmental disease, stressed that the cpidemie of asbestos-related disease is a public health failure rather than a failure of the medical profession. "The medical profession is accustomed to rapidly evaluating and treating known health problems," he said. "We take information made available to ns by science and use it to correct a problem." Not so with asbestos, says Seiikoff, even though it is known to be a serious health hazard. We are trapped by the substance. It has crept into our buildings, our schools, our homes, and our ears, and we have made an unconscious decision to aeetpt some level of AtPaatoa ramovaf: Wartar to Maw Yam City aattaaf aaattog araa wftara aataataa naa baan u*ea to claaamam pMUng. ha a waanno a raapratar ana apaeial garments to profact turn Mam paaaitla airbama aabaataa pantela*. Upon having araa. fta it rapueaa fa Pitpaaa at garment* ana ta artawar. (Photograph eourtaay at Du Pant Company.) mortality as the price we must pay for its usefulness. "One hundred years ago the problem was infectious disease," says Seiikoff. *Tbat was much easier to conquer. There was no public relations firm promot ing the tubercle bacillus and it was not deliberately woven into the fabric of our society." Another public health problem is the relatively poor understanding among most practicing physi cians regarding asbestos diseases. Unless a physician works in an area directly adjacent to an asbestos exposure site like a shipyard, be is unlikely to know . much about the subject According to Margaret Sloan, MD, of the Division .of Cancer Control and Rehabilitation at the National Cancer Institute (NCI), there is a serious deficit in physician knowledge concerning asbestos disease. To correct this, the NCI is aiming educational material at four categories of physicianc radiologists, patholo gists, chest physicians, snd various types of general practitioners. Says Sloan, "Radiologists are unable to interpret the indications of asbestosit such as pleural plaques on x-rays. Aod, due to the many different cellular patterns of asbestos disease, pathologists often have extreme difficulty in making a diagnosis. A disease 212 JAMA. Jan 10. 1990--Vo! 243. No. 3 Medical News So e r *II)G5fi0niSi Medical New* like mesothelioma often looks like metastatic cancer from another site. Also many chest physicians are totally unfamiliar with the manifestations of ashes* tos-related disease.** Perhaps most confusing of all, those concerned have not been able to agree on the most effective way of intervening in the course of asbestos disease. Will early detection have any impaet on mortality? Should all those known to have been exposed to asbestos be subjected to periodic sputum cytologies] examinations and chest x-ray films? Who will pay the massive costa of such long-term surveillance? There are no answers. "At this point screening to detect asbestos disease probably will not be effective," says the NIOSH's Robbins. "Wchave just begun programs to inventory all existing asbestos and to identify all the sites of human exposure, past and present The continued use of asbestos, despite clear knowledge of its dangers, verges on the criminal." Indeed, the foolhardiness of our past use of asbestos was the subject of a lengthy seminar at the recent annual meeting of the American Public Health Ass^ ciation in Hew York. According to David P. Rail, HD, director of the National Institute of Environmental Health Sciences, the peak mortality from the first major group of heavily exposed asbestos workers-- WW II shipyard workers--will occur in the coming decade. "A second group of heavily exposed workers." noted Rail, "is an erratic but slowly increasing group of shipyard, maintenance, insulation, and construction workers whose exposure to asbestos began in the late 40s and has continued to date. The use of asbestos has doubled during this time, and it will be the rote of public health physicians to deal with the disease which we can expect to occur The asbestos experts, mainly the staff at SelikolTs Environmental Sciences Laboratory, have been busily identifying several areas where exposure to asbestos can be expected to result in future disease. Not surprisingly, they predict continued shipyard asbestos disease. While the US Navy stopped using the substance in new ship construction several years ago, there is now afloat a massive fleet of ships eoated with asbestos. Over time, these ships must repaired, refitted, and eventually broken apart they become obsolete. Says Selikoff, "Our latest survey of workers'at continued on page t Sudden death brings East and West together en death from cardiovascular causes will elaim some 400,000 lives in this country during 1980. By definition of the World Health Organization, these are deaths occurring unexpectedly within six hours of symptom onset in apparently previously healthy persons or in patients considered to be in satisfactory condition. Sueh sudden deaths--some of whieh are being averted by increasing public use of cardiopulmonary resuscitation techniques, improved emergency-rescue systems, and sophisticated coro nary cars facilities-- probably will account for about 40% of the expeetod overall toll from cardie vascolar diseases In the United States this year. In tarn, cardiovascular mortality accounts for 32% of all deaths among Americana annually. So it is dear, say cardiologists such as G. Charles Oliver, MD, Washington Univer sity School of Medidne. St Louis, that sudden death is s leading cause of mor tality ia this country. It also is a major prob lem In other countries, inducting the Soviet Union. According to Anatoliy M. Vikhert, HD, DHS, National Cardiolo& Research Center, USSR Acade my of Hedieal Sciences, Hoscow, up to 75% of all deaths from coronary heart disease in that country occur suddenly. In 1973, the Joint US-USSR Committee for Health Cooperation agreed to focus on sudden death in some collaborative studies. At the eondusion of the Second Joint US-USSR Symposium on Sudden Death, held at Indiana University School of Med icine, Indianapolis, is De cember, that agreement was extended through 1982. Involved are further exchanges of visits and information and a third symposium is the Soviet Union in 1982. The new agreement was signed by symposium cochairmen Vikhert and Bernard Lown, MD, pro fessor of cardiology, Har vard University School of continued on next page DOUJ 06777 ..inttnurti /mm papt SIS Baltimore shipyard who are engaged solely with re pair work--no new construction--showed that among workers with 20 or more years on the job, 85% have ah* normal x-ray findings." No precautions are now being taken, and few warnings are given to the hundreds wi thousands of shipyard employees now at work. Another area of emerging concern is asbestos use in schools and public buildings. According to William J. N'icholson. MD. of Mount Sinai, there is a "good possibility** that when the latency period of asbestos disease is up. there will be a great deal of disease reiated to exposure in schools. Sprayed asbestos surfacing material has apparent* !y been used extensively in schools in the past. and. because of general disintegration, aided sometimes by vandalism, measured asbestos levels in some schools have been equivalent to occupational levels. As an example, according to Nicholson. 10% of all New Jersey's schools have sprayed asbestos surfaces, one third of whieh are crumbling. In Massachusetts. 20% of public schools have asbestos surfaces. Recently, the US House of Representatives approved a three-year program of 830 million in grants to school districts to search for asbestos in school buildings and 8300 million in loans to remove it. The measure has now gone to the Senate. Perhaps the most cruel exposure to asbestos is through household contact with another family mem ber who has been occupationally exposed. More and more of these cases are being reported. Because of the relatively low doses involved in household contact, it seems that some family members may be escaping asbestosis but suffering more cases of mesothelioma. This brings up the question of the doee-response ratio of asbestos, a point on whieh there is little . disagreement. Says Rail, "While it seems that the less the exposure, the more slowly asbestos disease will develop, it remains clear that there is no dose threshold below which asbestos exposure is safe." Adds Seiikoff. "There should be no asbestos expo sure at all. This is the only way to eliminate asbestos disease." The Environmental Protection Agency (EPA) con curs. "The EPA is convinced of the substantial risk with any asbestos exposure, even at very low levels," says Richard Guimond of the Office of Chemical Control of the EPA. Recent data to support the no-threshold contention eome from Philip E. Enterline. PhD, of the Depart ment of Biostatisties at the University of Pittsburgh. In his articie just published in Health Hazards of Asbestos Exposure (Ann A*YAcad Set, Vol 330,1979), Er.terline estimates cumulative dust exposure of asbestos workers in millions of partieles per cubic toot. A linear curve relating cumulative dust exposure of asbestos workers at the time of retirement to mortality from respiratory cancer shows that with no exposure there is no increase in mortality over standard rates, with modest exposure there is a -f oio--Vol J43 No 3 modest increase in mortality, and with heavy expo sure there is a great increase in mortality from respiratory cancer. The data also show, according to Enterline, that the "effects of asbestos exposure continue well past termination of exposure." Several embryonic efforts are now under way to regulate future asbestos use and to revise the current exposure standard. A major reduction in the current standard of 2 fibers per milliliter of air in the occupational environ ment is being considered by the Occupational Safety and Health Administration (OSHA) and NIOSH. The latter agency has recommended that this be reduced to 0.1 fibers per milliliter, but even this level would result in considerable exposure. "The asbestos situa tion is bad now and could get even worse." says Victor Alexander, MD. of OSHA. Ironically, the current standard is the result of a British study (since proved incorrect) that a level of 2 fibers per milliliter would substantially reduce the chance of developing early asbestosis. The cancer risk was not considered at all. At the EPA there are rumblings of a possible bah on the commercial use of asbestos, a proposal that, according to Business Week, is causing concern in the asbestos industry. The ageney at this time appears nowhere near implementing this proposal. However, says Guimond, "There is a high probabili ty that the EPA, at some time, will implement a total ban on commercial use of asbestos." Asbestos substitutes are being explored and used, of course. These include fiberglass for fire retarda tion; ceramic fiber and polyacrylonitrile for textiles; calcium silicate, mineral wool, and expanded perlite for building insulation; and a compound of eeilulose and clay wastes or a semimetallie friction material built around steel fiber and iron powder for brake linings. The latter two compounds, in particular, are said to be inferior to asbestos for such use. Perhaps Seiikoff offers the most plausible explana tion for the apparent paralysis in control efforts. "This is a social problem." be told JAMA medical news. "In the United States we have made an unacknowledged decision to control asbestos rather than to ban it. Banning is easy. Control Is much more complicated. "But we haven't lived up to our contract in this ease," he continued. "We haven't accepted the conse quences of control. I hear people rail all the time against regulation. I don't like regulation any more than the next guy, but without it no effort at control can be successful." On the subject of what lies ahead with asbestos, Seiikoff is gloomy. "I see exposure continuing," be said. "Things don't always turn out for the best Doctors know this perhaps best of all. Time doesn't solve everything. I'll just say that I have guarded pessimism about the whole thing."--by John Elliott Medieal News 319 rST0005506 t DOW 06778