Document mmY8NOMdD7Ywy46yE55gm5kqk

t 1058 OCCUPATIONAL SAFETY & HEALTH REPORTER standard [took effect)." Baker told the seminar. The most dramatic reduction was seen in melters, the workers with the heaviest exposure, from an average of 66.4 ag in 1980 to 36.8 ug in 1982. he said. Decrease in Impairment As blood lead levels dropped, researchers also detected a decrease in adverse neurobehavioral symptoms such as impaired verbal intelligence, faulty memory, and mood shifts. Baker continued. The first year of testing indicated a dose/response relationship that seemed to abate over the next two years, he said. Reduced vocabulary scores, modest memory impairment, and consistent mood changes were seen among exposed workers the first year, and were more apparent among workers with heavier exposure, those having blood lead levels of 49 ug, according to the Harvard researcher. By the second year, memory impairment and mood shifts were reduced, he stated, although a high correspondence on verbal abitity scores continued to be seen among workers with the heaviest exposure. Unfortunately, it is impossible to draw meaningful conclu sions from the results because of the small size of the study cohort. Baker asserted. In 1980,106 exposed workers and 63 non-exposed employees from a neighboring valve plant were tested. By the following year, the cohort had been cut in half by layoffs, and by the third year, only 56 workers comprised the test group. Since so many were lost to follow-up testing, there is "a great deal of bias" in the work. Baker stated. However. Harvard hopes to support these results with larger cohort testing in the near future, the researcher added. Meetings FIRST MEETING OF NEW NIOSH BOARD OF COUNSELORS SET FOR MARCH 20-21 The National Institute for Occupational Safety and Health's newly appointed Board of Scientific Counselors will hold its first meeting March 20-21 in Atlanta, Ga., according to a March 2 announcement (49 FR 7875). The board, whose membership was annovnced in Decem ber (Current Report. Dec. 22, 1983, p. 795), was formed to provide advice and guidance to NIOSH Director J. Donald Millar to ensure quality, timeliness, anr? usefulness in insti tute research, and proper dissemination of study results. included in the agenda for the initial meeting is an orientation to NIOSifs mission, goals, and budget, the notice reported. The panel will become familiar with specific research programs, and also with the NIOSH grants pro gram. the notice added. The session will be held from 1 p.m. to 4:30 p.m. March 20, and 9 un. to noon March 21, in Conference Room 207. Centers for Disease Control, 1600 Clifton Rd., NJS., Atlanta. Ga The meeting will be open to the public, with attendance limited only by the space available. For further information on the meeting, contact Ralph J. Touch. Assistant to the NIOSH Deputy Directjr. Building i. Room 3019. CDC. Atlanta, Ga. 30333; tel. (404) 329-3773 or FTS 236-3773. Asbestos NAS GROUP FINDS RISK TO HUMAN HEALTH IN NON-OCCUPATIONAL EXPOSURE TO ASBESTOS Non-occupational exposure to asbestiform fibers in air presents a risk to human health, according to a study conducted by the National Research Council, the research arm of the National Academy of Sciences, at the request of the Environmental Protection Agency. Although copies of the study will not be available to the general public until later in March, the study has been circulated through the Occupational Safety and Health Ad ministration's health standards division and is under review there. The report could contain useful information, despite the fact that most of the data obtained apply to nonoccupational exposures, according to agency spokesman Doug Clark. "Nonoccupationai Health Risks of Asbestiform Fibers" considers the health risks posed by nonoccupationai airborne exposures, an important issue because many people may be exposed to these materials, although at relatively low levels, according to the study While the extent of risk is highly uncertain, evidence for the existence of the risk includes the following; Large excesses of lung cancer, mesothelioma, pulmo nary fibrosis, and other pleural abnormalities have been found among workers occupationally exposed to asbestos. Presumably, nonoccupationai exposures would result in qualitatively similar effects. Both a statistically excessive number of cases of meso thelioma and an excess frequency of pleural abnormalities have been observed among household contacts of asbestos workers. Asbestiform fibers are distributed extensively outside the workplace, although usually in minute quantities. The major pathological effect' associated with human exposure to airborne asbestos have been duplicated experi mentally in animals. Increases in cell replication and other abnormalities have been seen in cultures in tracheal lining cells from humans and animals after the cells were exposed to synthet ic or natural asbestiform materials. Although estimating the extent of health risks from nonoc cupationai exposure to asbestiform fibers is "fraught with uncertainty," the committee made a quantitative estimate of the risk of excess lung cancer and mesothelioma that might occur in persons breathing low levels of asbestos in the air. A concentration of 0.0004 fibers/cm1 was deemed reasonable to use in such calculations because it is the approximate average level that may be encountered in indoor and outdoor air. If a person inhaled air containing asbestos at that level throughout a 73-year lifetime, the committee's best judgment is that the lifetime risk of meso thelioma would be approximately nine in a million. Epide miological data indicate that the corresponding lifetime risk for lung cancer would be about one in a million for male smokers and less for nonsmokers or female smokers. Risk Assessment Guides The report cautioned that these risk estimates should be viewed as guides to the qualitative assessment of nonoccu pationai health risks from asbestos and asbestiform fibers, not as definitive estimates of the amount of disease to be anticipated. These estimates and other considerations lead to the following conclusions about risk, according to the report: Some deaths from mesothelioma and lung cancer will probably result from current and past levels of exposure to asbestos in ambient air. Excess deaths from other diseases, such as asbestosis. and from exposures to other asbestiform fibers are also possible but are not likely to be as numerous as those from asbestos-induced mesotheliomas or lung cancer. 3-8-84 Copyright C 1984 sv The Bureau of National Affairs. Inc 0O9S-H37/*fJO- SO 006174 SWB-55 CURRENT REPORT The number of annual deaths expected to result from Mich exposures is very uncertain, but it is virtually certain to be lower, and probably much lower, than these resulting from past, heavier occupational exposures to asbestos. Deaths from past occupational exposures to asbestos can reasonably be estimated to total several thousand per year in the U.S. during the next few years. Among these, more deaths from lung cancer than from mesothelioma can be expected. Continuous lifetime exposure to asbes.us would probably result in substantially more mesotheliomas than lung can cers. Inhalation of asbestos in ambient air may result in such a lifetime exposure. The strong dependence of mesothe lioma rates on time from first exposure would make chil dren more vulnerable than adults to eventual development of this disease given the same exposure. The report noted that some of the physical properties of asbestiform fibers appear to be important in causing ad verse health effects, but the specific properties that are necessary and sufficient are not known. One clearly impor tant characteristic is respirability. In addition, longer, thin ner fibers appear to be more pathogenic than shorter, thicker fibers, but there is not a minimum size below which no effects would be expected, the study emphasized. Num ber, rather than mass and durability of fibers also seem to be significant factors in pathogenicity of asbestiform fibers, the report suggested. Recommendations Contained in Report Further, the committee recommended the following actions: Systematic monitoring and characterization of asbesti form fibers with standardized methods should be undertaken in nonoccupational environments, including urban, rural, indoor, and outdoor locations where exposure may be of special concern. A program of systematic surveillance should be under taken to determine the extent to which the occurrence of mesothelioma and lung cancer is associated with exposure to asbestiform fibers. Cessation of cigarette smoking should be encouraged in view of the multiplicative effect of smokinp and asbestos exposure in increasing the risk for lung can. or. Steps should be taken to educate both tne medical r rofession and the general public concerning possible expo sures to asbestiform fibers and the resulting health effects. Copies of the report will be available for purchase this month at S22.50 each from the National Academy Press, National Research Council, 2101 Constitution Ave., N.W.. Washington. D.C. 20418. Underground Construction FIRMS QUESTION NEED FOR TWO TEAMS. CRITICIZE BROAD APPLICATION OF RULE The oroad application of the Occupational Safety and Health Administration's proposed underground construction standard to include virtually ail underground construction activities was strongly criticized by companies and trade groups commenting on the Aug. 5 proposal. Issued Aug 5. the proposal would replace the agency's current rule, for tunnels and shafts (Current Report. Aug. 8. 1983. p 2271 Colorado Contractors Association. Inc . asserted that OSHA s present standard snould not be expanded to cover 5059 9 such areas as decked over cut-and-cover operations and manholes connected to sewer systems. The contractors group claimed these types of operations do not need the "stringent requirements suggested m the proposal." Similarly, the Associated General Contractors of Amer ica. Inc., of Charlotte. N.C.. said that it is "totally illogical" to force the tougher underground standards on cut-andcover operations and manhole construction. Boeing Aero space Company noted that the standard as proposed by OSHA would cover minor modification cf underground buildings and structures such as missile silos, "where little if any structural change Is made." Forcing the "unnecessarily severe" safety requirements on these types of operations could "mandate practices that are not as safe as other methods." Boeing claimed. The Connecticut Construction Industries Association. Inc., said the two five-member rescue teams required by OSHA would "cause exorbitant payroll cost increases," especially on round-the-clock pipe jacking operations. The Connecticut organization asserted that only one rescue squad is neces sary, adding that the workers on the surface of an under ground operation should be counted towards that rescue team, as well as a "manned" fire department station located "within a reasonable distance from the project." The com pany called for an exemption from the two rescue team requirements for small jobs. The Colorado Contractors Association said the use of the two rescue squads is "an added and unnecessary burden on the employer." The association recor.m.cnded that only one rescue team should be required "when there is no danger of any environmental or structural hazards in underground operation" Communications, Hoisting Boeing Construction noted that OSHA's requirement for the use of "power-assisted means of voice communication" is "too restrictive." especially in situations where there is extensive noise on the site. Boeing called for the standard to require "an effective backup means of communication to be provided," such as flashing lights, bells, gongs, or sirens, instead of telephones or radios. The Colorado Contractors Association recommended that Of?" IA use the communications system set up by the Mine Safety and Health Administration, which requires that em ployees working alone in hazardous areas should be within hearing distance or visual distance of other workers. In the hoisting area. Granite Construction Company claimed the "rigid requirements for guides and safeties ... would be very restrictive, impractical and. in some cases, impossible for general application" to all shaft construction operations, due to their different sizes, configurations, in tended functions, and required construction methods. Gran ite claimed the strict requirements are not necessary for hoisting operations that do not involve personnel Granite recommended holding the standard in abeyance until further study is completed. In response to OSHA's request for information on the use of catalvtic converters on mobile diese! Dowered equipment, Engelhard Industries Division said their use. along with the use of proper ventilation techniques, would substantially improve the mine environment by eliminating odorous and irritating hydrocarbon emissions." Engelhard, a catalyst manufacturer, dismissed concerns that exhaus. from cata lytic converters could raise temperatures, noting that the temperature increases only about five to 10 degrees Fahren heit. "which is not sigmheant in terms of average diesel exhaust temperatures." 3-e-s* Occupational Salary t Health Reporter 00SS-3237,/S0- SO 006175