Document 99mnQvKQdgKGyJz3wbQO7LzO7

7 Industrial Hygiene Forum Franklin D. Griffith, Ph.D. Department Editor The Industrial Hygiene Forum is designed as a medium of exchange for members and readers who wish to share their "know-how " with othersyet avoidthe necessity ofprepar ing a full and detailed manuscript on the subject. This is your opportunity to share with others your "know-how. " timely tips, new ideas, etc., on any aspect of industrial hygiene. Exceptions are matters of opinion and comments on published manuscripts; these will be published elsewhere in the Journal. Submissions should be signed and markedfor publication in the Forum. Contributions to the Industrial Hygiene Forum willnot bepeer reviewed but the right is reserved to edit accepted contributions. The success of the "Forum" of course will depend upon the contributions from you, our readers. For consideration, send your contribu tions directly to Franklin O. Griffith, Ph.D., Industrial Hygiene Forum, AlHA Journal, 475 Wolf Ledges Parkway, Akron. OH 44311-1087, (216) 762-7294. Asbestos Exposure Associated with Automotive Brake Repair in Pennsylvania L. LA MONT MOORE Safety Sciences Department. Indiana University of Pennsylvania. 205 L'hler Hall. Indiana. PA 15705 Introduction Automobile mechamcsare potentially exposed to asbestos libers released during brake repair work in service stations, car dealer ships and mulller shops nationwide. Asbes tos libers are released when service mechan ics clean dust residue Irom contaminated drum or wheel parts. Personal samples were collected Irom the breathing /ones of auto mobile mechanics to estimate their asbestos exposure while perlorming actual brake re moval and repair work. Exposure measure ments were made in thirty -one dillerent facil ities with widely diverse work practices. The estimated average asbestos exposure during actual repair work was <0.03 liber per cubic centimeter II ee) based on thirty-live xepalate samples. II zero exposure were assumed lor the unsampled portions ol these shifts, the mean eight-hour, time-weighted average would have been <0.002 I ce. Materials and Methods Personal samples were draw n Irom the breath ing /ones ol employees performing brake service work. Sampling encompassed the entire period required to complete the as signed tasks. In most instances the assign ment consisted of pulling all lour wheels, visually inspecting the front disc pads, then removing and replacing both sets of rear brake shoes. Each sample was collected on an l).8-gm pore si/e. 25-mm diameter mixed cellulose ester filter mounted in an open-face. 5-cm diameter cassette. Individual tillers were at tached to the employees' outer garments in the breathing /one. Air was drawn through these tillers using MSA Model G sampling pumps. The flow rate on each pump was set at 1.7 Lpm as established by prior calibra tion by a soapbubble meter. The sampling rate was checked periodically and adjusted if necessary to maintain the desired setting. At the conclusion ol each survey , the individual cassette was sealed, labeled and submitted to an approved industrial hygiene laboratory. At the laboratory, a small portion ol each filter was cut and mounted on a glass slide in a medium consisting of dimethylphthalate and diethyloxalate, then covered w ith a glass cover slip. Each sample was subsequently counted on a Zeiss microscope equipped with phase contrast and a porton reticle. The reticle is calibrated at a magnification ol 400 times with the stage micrometer from Bausch and Lomb Optical with scales of 0.10 mm and 0.01 mm. Results and Discussion One major finding ol this study was that automobile mechanics were very well educated about the danger of using compressed air to clean dust Irom wheel or brake parts Compressed air was used on a limned basis in only oneol the thirty-one lacilities surveyed. The data summarized in Table I suggest that employee exposure typically tails well below the OSH A permissible exposure limit (PEL) ol 0.2 f cc. We point out that these measurements were collected during repairs on a representative number ol vehicle makes and models, in a broad spectrum ol repair lacilities employing a wide diversity ot work practices. In 75G ol the instances where exposure exceeded the mean (0.03 I cc). poor work practices were involved. Where employees utilized good work practices such as the use ol a spray-type, aerosol liquid cleaner -- seventy percent ol the exposure measure ments tell below the mean. Our lindings seem somewhat lower than those reported by Kauppinenand Korhonen.11 but this may be due to less frequent use ol compressed air for cleaning. In most ol the Pennsylvania facilities surveyed, each employ ee performed an average of two or three brake repairs per week. Based on our inter views. it would be unusual for a mechanic to perform brake service work on more than one vehicle per day. The mean length of lime required to com plete these brake jobs was 29 min. If one expects exposure to average <0.03 f, cc dur ing this high risk period with zero exposure assumed for the remainder of the shift, the employee's eight-hour, time-weighted aver age could be predicted to average <0.002 I cc on days when brake repairs are under taken. Conclusions Appendix Fto29CFR 1910.1001 summarizes non-mandatory work practices and engineer ing controls lorautomotive brake repair oper ations.'' Our study supports OSHA's posi tion that management in the automobile serv ice industry can keep employee exposure below 0 I I cc and avoid costly compliance programs. 1 he most readily accepted, costelfective approach seems to be the use of spray-type, aerosol cans ol brake cleaning solvents. I hese containers deliver a mist with considerably less lorce than shop air hoses fitted with a solvent delivery system. The aerosol spray approach may be equally as TABLE I Summary of Asbestos Exposure Monitoring Number ot Exposure Measurements Range for Duration of Sample Period (minutes) Asbestos Concentration' in fiber/cc (Median) (Mean) (Range) 35 10 - 60 <0.02 <0.03 <0.01-0.15 'Exposure estimates above reflect actual time-weighted averages for the sampling period during which brake service work was carried out. not the full eight-hour shift. Capyngm <988 American inOuSfnal Hygiene Association A 12 Am Ind Hyg Assoc J (49) January 1988 k HWBUI0013307 etleciive a* vacuum systems equipped with HEPA tillers. provided that the contami nated liquid drippings are caught in a drip pan and dn.poi.ed ol in accordance with appropriate waste disposal regulations. Other work practices which deserve man agement consideration include limiting the height ot the car-litt or service rack so that wheel parts are not disassembled at (or above) the level ol the employee's breathing /one and prohibiting employees I rum dump ing dust residue from brake drums dtrectlv on the shop floor. Contaminated dust can be vacuumed or carefully dumped into waste liquid containers which subsequently will be used to catch aerosol drippings. References 1 Kauppinen, T. and K. Korhenon: Expo sure to Asbestos During Brake Mainte nance of Automotive Vehicles by Dif ferent Methods Am. Ind. Hyg. Assoc. J 48/5):499-504 (1987) 2. Asbestos. Tremolite. Anthophyllite and Antmohte.' Code of Federal Regulations. Title29. Subtitle B. Part 1910. Subpart Z June 20. 1986. Ribavirin -- Exposure to Health Care Workers SUSAN B. LEE Safety Director. The Children's Hospital. 300 Longwood Ave.. Boston. MA 02115 employee complaints ot irritation and concerns about reproductive toxieitv: to report results ol env ironmcntal mon itoring lor airborne ribavirin. Administration of Ribavirin Introduction Ribavirin (1-beta-D-riboluranosvl-l .2.4 tnazole-3-carboxamide). an antiv iral drug, has the Food and Drug Administration (EDA) approval for administration as an aerosol to selected infants and young children with severe lower-respiratory tract infections due to respiratory syncytial virus (RSV).'1' Ribavirin (Virazole'") has been sold in Mexico for almost twenty years under the brand name Vilonaas an orally administered remedy for viral infections It is noteworthy as one of several drugs being tested lor treatment of AIDS and AIDS related com plex (ARC).,JI Warnings, contraindications, precautions and a description of adverse reactions are given in the product monograph, as they might affect the patient and the treatment of the disease. Some of the potential adverse health el lects for health care workers administering riba virin may be carcinogenesis, tertility impair ment and feiotoxicity. L se of the drug is contraindicated in women or girls who are pregnant or may become pregnant during exposure to ribavirin. Ribavirin has been found to be teratolethal and, or embryolethal in nearly all animal species in which it has been tested. It has shown structural and meta bolic similarity to other cytotoxic agents, is mutagenic in mammalian cell culture and has caused cell transformation in an in vitro mammalian system. The purpose of this paper is as follows: to describe the method of administra tion of aerosolized rtbav irin as the source of occupational exposure to the drug: to describe policies and procedures devel oped by one hospital in the absence of any data on the level of exposure, given A sterile dilution ol lyophih/ed ribavirin is prepared such that the concentration of the solution is 20 mg mL. The small-particle aerosol generator (SPAG-2) delivers the solution as a small, uniform size aerosol (95(, of particles < 5 (i diam)'1' which is "contained" inside a hood or tent around the patient's breathing /one. The average aero sol concentration for a I 2 hr period would be 190 qg L (0.19 mg L) ol air. The aerosol is administered for 20 of 24 hr for five consecu tive days. ' Occupational Exposure Direct exposure occurs when nurses, respira tory therapists, doctors or others actually enter the tent to care for the patient. Because these patients are usually very young and quite ill. the tasks inv olved in caring lor them may be quite frequent and ol relatively long duration (15 min to I hrat a time). It should be noted that the care is to a "babe in arms." and thisexposure is in theemployee's breath ing zone. Indirect exposure may occur because the tent or hood is not an airtight tillered system. The pressure inside the tent is positive with respect to the room. and. therelore. the air borne ribavirin particles may leak into the room creating potential lor inhalation to anyone entering the room Direct caregivers who may enter and leave the room to check on the patient's status, without entering the tent, may be exposed in this way. The greater concern of indirect exposure is to the par ents. who may visit anytime day or night and who may spend the entire night in the patient's room. Employees'complaints of headaches, burn ing and dryness of the eyes, coughing and dry ness of the upper respiratory tract resulted in the Safety Office's becoming involved in in vestigating the matter of occupational expo sure to ribavirin Since the majority ol the CooyDgm Idas American fnausinai hygiene Association Am Ins Hyg Assoc J (A9) January. 1988 exposed health care workers are women in theirchtldbearing years, the potential lor Ictal death or damage was ol even higher concern than the above-mentioned acute symptoms. Method and Results In the absence ol any data on the level ol exposure and to most prudently address the potential hazard to unborn children ol stall members, it was recommended that preg nant workers (or those attempting to become pregnant) be excluded trom any exposure by not caring lor patients on ribavirin. In response to the acute symptoms de scribed above, an industrial hygiene survey was conducted using a calibrated llcndix pump, open-face. 37 mm cassettes and 0.8 mMCEF. Preliminary results showed ambi ent exposure levels ol 2.35 to 2.80 mg m` airborne dust. Based on these results and assuming the "dust" was ribavirin, the Salety Office required the following protection lor stall who enter the room while ribavirin aerosol was being administered: to prevent eye irritation goggles; tight-tilting to prevent inhalation approved dust mist respirators)3M Company 8710. or equivalent) properly worn and luted. to prevent inadvertent ingestion use ol long-sleeved gow ns and latex gloves, scrupulous personal hygiene, hand and any exposed skin surface washing: to assure employees understand potential hazards, routes ol entry and limitations of protective measures dissemination ol product literature and training sessions. Lsing an identical method and collecting five additional samples, wc latthe Children's Hospital) were unable to contirm the airborne dust concentration seen in the first two sam ples. All other samples were below the limn of detection in exposed and non-exposed areas. Based on these results, the requirement for strict use of personal protective equipment was limited to the occasions when employees enter the tent. A-13