Neuropsychologic “impairment” in a cohort of hospital workers chronically exposed to ethylene oxide

Abstract

Ethylene Oxide is widely used to sterilize heat-sensitive materials. Acute and chronic neurogenic effects to the central and peripheral nervous system in man and animals have been described. To assess the chronic, subtle neuropsychologic effects of ethylene oxide, we performed a cross-sectional study of 25 hospital central supply workers exposed to low levels of ethylene oxide and 24 unexposed control workers. Subjects were tested using a neuropsychological screening battery by examiners blinded to exposure status. Testing results were reviewed independently by two neuropsychologists without knowledge of exposure. Subject status was categorized as normal, "impaired," or disagreement (between the two neuropsychologists). There were significantly more subjects concordantly judged as impaired in the exposed group versus the control group (chi 2 (2) = 6.0861, p less than 0.05). Although limited by the cross-sectional study design and the global categorization, these findings suggest that CNS dysfunction and cognitive impairment may result from chronic ethylene oxide exposure in hospital central supply units.

Integrative literature review: Ethylene oxide exposure signs and symptoms

“…Specific CBC changes included abnormal WBC counts (significantly low or high), high hematocrit, low platelets, and low lymphocyte counts (Lamontagne et al., 1993; Shaham et al., 2000). Diminished cognitive ability was determined via IQ tests, neuropsychological screening battery tests, and comparisons to traumatic brain injury (TBI) cohorts (Estrin et al., 1990; Klees et al., 1990; Patch & Hartlage, 2001). Crystal et al.…”

“…Adverse reproductive outcomes and diminished cognitive ability were also associated with prolonged exposure (Estrin et al, 1990;Gresie-Brusin et al, 2007;Klees et al, 1990;Neghab et al, 2012;Patch & Hartlage, 2001;Rowland et al, 1996).…”

“…Specific CBC changes included abnormal WBC counts (significantly low or high), high hematocrit, low platelets, and low lymphocyte counts (Lamontagne et al, 1993;Shaham et al, 2000). Diminished cognitive ability was determined via IQ tests, neuropsychological screening battery tests, and comparisons to traumatic brain injury (TBI) cohorts (Estrin et al, 1990;Klees et al, 1990;Patch & Hartlage, 2001). Crystal et al (1988) reported that the pattern of cognitive decline associated with EtO exposure involves "intact learning and profound forgetting," a marked difference from other memory disorders resulting from dementia, Alzheimer's disease, or stroke (p. 567).…”

Ethylene Oxide and Cns Dysfunction

“…The March issue of Journal of Toxicology Clinical Toxicology carries an editorial (1) and two research reports (2,3), all by investigators at University of California at San Francisco (UCSF), on the neurotoxicity of ethylene oxide (EtO). Attorneys for a company involved in EtO litigation have asked for a review of those and related materials.…”

Ethylene Oxide - Authors' Response

“…This is the reason researchers employ more than one judge. The neuropsychologists in the Klees et al study (2) held different views on the application of personality tests in the assessment of cognitive impairments. Each judged the subjects following his or her personal clinical criteria.…”