Health hazard evaluation report: HETA-2004-0372-3054, evaluation of neurological dysfunction among workers exposed to trichloroethylene, Entek International, Lebanon, Oregon.
On August 24, 2004, NIOSH received a technical assistance request from the Oregon Department of Human Services concerning dementia and neurologic dysfunction among workers exposed to TCE at Entek International in Lebanon, Oregon. In an initial NIOSH site visit in November 2004, NIOSH investigators found GA air concentrations of TCE ranging from 20 to 40 ppm in production areas. A medical questionnaire revealed that 48% of Entek International workers reported feeling high or lightheaded while at work in the last 30 days, compared to 19% of non-TCE exposed workers at an adjacent facility, Entek Manufacturing. In a follow-up site visit in June 2005, NIOSH investigators collected full-shift and shorter-term PBZ and GA air samples for TCE on study participants on all four production schedules over a one-week period. Noise exposures were also measured. The medical evaluation included a health questionnaire, five neurobehavioral tests (Grooved Pegboard, Postural Sway, Trail Making, Visual Contrast Sensitivity, and Symbol Color Recode), and biological monitoring for TCAA, a metabolite of TCE. Mean full-shift PBZ air concentrations for TCE were below the OSHA PEL of 100 ppm, but above the extended 12-hour work-shift adjusted NIOSH REL of 21 ppm for extruders, winders, rovers, team leads, and supervisors. Shorter-term (13 to 48 minutes) TCE exposures ranged from 30 to 445 ppm, with the highest concentrations occurring during line maintenance. Production employees wore elastomeric half-mask air-purifying respirators equipped with a combination organic vapor/HEPA filter cartridge during product changeover or line maintenance activities, but not typically during routine work activities. Noise levels exceeded the NIOSH REL in extrusion, winding, palletizing, maintenance, and utility/rover jobs (such as fork lift operators); radios in some work areas contributed to noise exposures. Most workers wore hearing protection (plugs or muffs). Of 129 study participants, 82 were exposed to TCE. The groups were similar in age, but differed in average tenure and in education levels. The exposed group had a higher prevalence of former and current smokers, and consumed more alcoholic drinks on average than the unexposed. The TCE-exposed group had deficits in the following neurobehavioral tests compared to the non-exposed workers: lower visual contrast sensitivity scores for both eyes at 6 cycles per degree and at 12 cycles per degree for the right eye, a larger postural sway area for the most challenging test condition, and slower completion time in the Grooved Pegboard Test. The median urinary TCAA level in the exposed group was 50 mg/g creatinine (range: 0-223) compared to 0 mg/g creatinine (range: 0-2.2) in the unexposed. A total of 22 TCE-exposed participants (26.8%) had urinary TCAA levels over the ACGIH BEI (100 mg/g creatinine).
Region-10; Hazards-Confirmed; Noise; Respirators; Hearing-protection; Central-nervous-system-disorders; Neurological-reactions; Neuromotor-function; Neuromotor-system-disorders; Respiratory-protective-equipment; Personal-protective-equipment; Gloves; Skin-exposure; Humans; Hearing-protection; Organic-vapors; Organic-solvents; Solvents; Demographic-characteristics; Statistical-analysis