title: Airborne asbestos exposures associated with gasket and packing replacement: a simulation study of flange and valve repair work and an assessment of exposure variables.
abstract: A simulation study was conducted to evaluate worker and area exposure to airborne asbestos associated with the replacement of asbestos-containing gaskets and packing materials from flanges and valves and assess the influence of several variables previously not investigated. Additionally, potential of take home exposures from clothing worn during the study was characterized. Our data showed that product type, ventilation type, gasket location, flange or bonnet size, number of flanges involved, surface characteristics, gasket surface adherence, and even activity type did not have a significant effect on worker exposures. Average worker asbestos exposures during flange gasket work (PCME=0.166 f/cc, 12-59 min) were similar to average worker asbestos exposures during valve overhaul work (PCME=0.165 f/cc, 7-76 min). Average 8-h TWA asbestos exposures were estimated to range from 0.010 to 0.062 f/cc. Handling clothes worn during gasket and packing replacement activities demonstrated exposures that were 0.71% (0.0009 f/cc 40-h TWA) of the airborne asbestos concentration experienced during the 5 days of the study. Despite the many variables considered in this study, exposures during gasket and packing replacement occur within a relatively narrow range, are below current and historical occupational exposure limits for asbestos, and are consistent with previously published data.
authors.affiliation: Cardno ChemRisk, LLC, 130 Vantis, Suite 170, Aliso Viejo, CA 92656, United States. Electronic address: Amy.Madl@cardno.com.
authors.forename: Amy K
authors.initials: AK
authors.lastname: Madl
authors.affiliation: Cardno ChemRisk, LLC, 4840 Pearl East Circle, Suite 300 West, Boulder, CO 80301, United States.
authors.forename: Kathryn D
authors.initials: KD
authors.lastname: Devlin
authors.affiliation: Cardno ChemRisk, LLC, 101 2nd Street, Suite 700, San Francisco, CA 94105, United States.
authors.forename: Angela L
authors.initials: AL
authors.lastname: Perez
authors.affiliation: Cardno ChemRisk, LLC, 101 2nd Street, Suite 700, San Francisco, CA 94105, United States.
authors.forename: Dana M
authors.initials: DM
authors.lastname: Hollins
authors.affiliation: Cardno ChemRisk, LLC, 130 Vantis, Suite 170, Aliso Viejo, CA 92656, United States.
authors.forename: Dallas M
authors.initials: DM
authors.lastname: Cowan
authors.affiliation: Cardno ChemRisk, LLC, 20 Stanwix Street, Suite 505, Pittsburgh, PA 15222, United States.
authors.forename: Paul K
authors.initials: PK
authors.lastname: Scott
authors.affiliation: Cardno ChemRisk, LLC, 101 2nd Street, Suite 700, San Francisco, CA 94105, United States.
authors.forename: Katherine
authors.initials: K
authors.lastname: White
authors.affiliation: Cardno ChemRisk, LLC, 130 Vantis, Suite 170, Aliso Viejo, CA 92656, United States.
authors.forename: Thales J
authors.initials: TJ
authors.lastname: Cheng
authors.affiliation: Cardno ChemRisk, LLC, 1101 Periwinkle Way, Suite #101, Sanibel, FL 33957, United States.
authors.forename: John L
authors.initials: JL
authors.lastname: Henshaw
mesh_terms: D000395:Air Pollutants, Occupational / Q000032:analysis*; D001194:Asbestos / Q000032:analysis*; D004784:Environmental Monitoring; D006801:Humans; D019570:Inhalation Exposure / Q000032:analysis*; D016273:Occupational Exposure / Q000032:analysis*; D012767:Ships; D014691:Ventilation
chemical_list: D000395:Air Pollutants, Occupational; D001194:Asbestos
keywords: Bonnet; Equipment; Exposure; Flange; Installation; Removal; Valve