edited by MIRIAM C. NAGEL Awn High Schwl Avon. CT 06001
Is Your Lab Really Safe from Asbestos? Mlrlarn C. Nagel 152 Junipw Dr.
Awn. CT 06001 Most schools and colleges have checked their ceilings, insulation, and floor tiles for friable asbestos since the Environmental Protection Agency's Office of Toxic Substances began enforcing the Asbestos School Hazard and Control Act in March of 1984. But have you checked inside your lab drawers and cabinets for asbestos? Are there any wire gauze squares with crumbling asbestos centers still lying around? Any asbestos mats? Asbestos gloves? These items were routinely offered in school supply catalogs and were even advertised as OSHA approved in 1979 (1). Old equipment is commonly found inschoollahs. Highschools and colleges tend to keep equipment far beyond any reasonable use. A physics teacher I know keeps an old pair of asbestos gloves in his lecture table drawer. I have chided him about keeping them. He proudly shows the new asbestos-free gloves he got for students to use, but said he just could not bring himself to throw away his old favorite asbestos gloves. Those old safety tongs for beakers, their jaws covered with woven asbestos mittens, I wonder if they are still in his drawer too? If they are, some of the asbestos is probably crumbling into the drawers from which it can easily by swept out into the air, right under the nose of a student-or teacher. Sometimes the equipment has been thrown away, hut no one has cleaned the drawer and asbestos fibers are still loose in it. A student working close to such loose fibers has a high exposure for a short time. The teacher endures a longer exposure in the room. Both are at risk. "In Waterbury, Conn., asbestos manufacturers are being sued by the estate of an ex-teacher who died a t 57 of mesothelioma, a cancer usually found in shipyard workers and others exposed to high amounts of asbestos fibers." This item, in US.News and World Report in 1984 (2),does not say what the teacher taught. Odds are the teacher had not been in a chem lab handling asbestos squares and using asbestos-covered beaker tongs. The chemistry teacher is exposed to all the environmental asbestos in the school buildings plus the laboratory hazards. The dose-response curve for exposure to ashestos is uncertain. The risks of breathing high concentrations is well documented, but "there is no evidence in occupational studiesto show there is a thresholdlevel below which there are no adverse effects", according to Chemical & Engineering News in 1985 (3).Irving Selikoff of Mount Sinai School of Medicine, City University of New York, one of the top authorities on asbestos diseases, points out that once asbestos gets into the lungs i t is there forever (4). The source of asbestos exposure is not always immediately obvious. One 37-year-old lung-tumor victim was exposed to asbestos fibers from her father's clothes when she was a child. Asbestosis and the always-fatal cancer, mesothelioma, do not usually develop until 20-30 years after exposure (5). OSHA set the permissible exposure limit, PEL, at 0.2 fibers of asbestos per cubic centimeter of air. (6) While that standard is set for an eight-hour day, it is so low that a teacher, handling classes in a lab continually for most of a day, could expect a significant exposure if old asbestos equipment is still around or if the dust from the equipment is routinely disturbed. Since asbestos is a hazard when it is
airborne.. exoosure is measured bv takine ambient air sam. ples in higb-risk workplaces. The samples are analyzed using an outical microsco~e(7). It is vew unlikely that an academic laboratory would be checked for asbestos by this technique, though i t would probably be desirable. Most building inspections-for asbestos concentrate on the insulation and wall and ceiling surfaces, which were often covered with sprayed-on asbestos for fireproofing until about 1973. The protection provided by the fireproofing surely did save some lives. But the ashestos eventually comes loose and becomes friable. (8) In chemistry labs the teacher has to be wary even if the buildine has passed insuection. If the insuection included air samples, ft is important to know when the samples were taken. The ambient air when no one is in the lab could be quite different from what it is like under actual working conditions, with 20 to 30 students handling.equipment continuously in and out of closets and drawers during the day. Some pollution problems developed from advances in technolo& and some from new chemicals developed to control serious pests. Not so with asbestos, it is a natural product. Asbestos has beenmined, used, and known to be hazardous since ancient times. The fibrous minerals, collectively called asbestos, are magnesium silicates that often also include iron and sodium or calcium. The fibers have been mined and woven into urotective cloth since at least the first century when the om& naturalist Pliny observed asbestos workers were sickly and died young. The real surae in asbestos use came with the industrial ;evolution. ~ s b e s t o swas used to make working with steam engines safer and more efficient. By 1906fibrosis of the lungs was being diagnosed in asbestos workers. In 1918 the United States Department of Labor oublished reuorts on asbestos hazards. and life insurance companies staked refusing insurance to'asbestos workers. Durine World War 11 asbestos use increased tremendously witg the war effort. By 1970 the documentation of the risk to workers exposed to asbestos was so extensive that OSHA set a standard of five fibers per cubic centimeter, later to be revised down to two fibers per cubic centimeter and now to 0.2 fibers cm3. But real action on curtailing the use of asbestos did not begin until a damage suit award of $79.000 to the estate of a n insulation worker who died of mesothelioma was upheld in 1973 (9). So much history of the hazards of asbestos exposure cannot be ignored by the prudent teacher. Disposal of equipment with asbestos and cleanun of cabinets and drawers has to be done. Great care must be taken not to create more hazardous conditions in the urocess. As the waste is collected, it must be sealed into bags. Regulations change, so any method of disposal must be checked, but in 1985 the EPA allowed asbestos waste to be buried in approved landfill where it had to he covered with 6 inches of dirt within the day (10). Asbestos waste disposal should be a one-time problem. Replacement equipment will not have asbestos insulation. Literature Clted
Volume 65 Number 3 March 1988
263
