title: Airborne endotoxin predicts symptoms in non-mouse-sensitized technicians and research scientists exposed to laboratory mice.
abstract: Research scientists, laboratory technicians, and animal handlers who work with animals frequently report respiratory and skin symptoms from exposure to laboratory animals (LA). However, on the basis of prick skin tests or RASTs, only half are sensitized to LA. We hypothesized that aerosolized endotoxin from mouse work is responsible for symptoms in nonsensitized workers. We performed a cross-sectional study of 269/310 (87%) workers at a research institution. Subjects completed a questionnaire and underwent prick skin tests (n = 254) or RASTs (n = 16) for environmental and LA allergens. We measured airborne mouse allergen and endotoxin in the animal facility and in research laboratories. Of 212 workers not sensitized to mice, 34 (16%) reported symptoms compared with 26 (46%) of mouse-sensitized workers (p < 0.001). Symptomatic workers were more likely to be atopic, regardless of mouse sensitization status. Symptomatic non-mouse-sensitized workers spent more time performing animal experiments in the animal facility (p = 0.0001) and in their own laboratories (p < 0.0001) and had higher daily endotoxin exposure (p = 0.008) compared with asymptomatic coworkers. In a multivariate model, daily endotoxin exposure most strongly predicted symptoms to mice in non-mouse-sensitized workers (odds ratio = 30.8, p = 0.003). We conclude that airborne endotoxin is associated with respiratory symptoms to mice in non-mouse-sensitized scientists and technicians.
authors.affiliation: Department of Medicine, Division of Environmental and Occupational Health Sciences, National Jewish Medical and Research Center, 1400 Jackson Street, Denver, CO 80206, USA. pachecok@njc.org
authors.forename: Karin A
authors.initials: KA
authors.lastname: Pacheco
authors.forename: Charles
authors.initials: C
authors.lastname: McCammon
authors.forename: Andrew H
authors.initials: AH
authors.lastname: Liu
authors.forename: Peter S
authors.initials: PS
authors.lastname: Thorne
authors.forename: Marsha E
authors.initials: ME
authors.lastname: O'Neill
authors.forename: John
authors.initials: J
authors.lastname: Martyny
authors.forename: Lee S
authors.initials: LS
authors.lastname: Newman
authors.forename: Richard F
authors.initials: RF
authors.lastname: Hamman
authors.forename: Cecile S
authors.initials: CS
authors.lastname: Rose
mesh_terms: D000293:Adolescent; D000328:Adult; D000395:Air Pollutants, Occupational / Q000009:adverse effects* / Q000276:immunology; D000485:Allergens / Q000008:administration & dosage / Q000009:adverse effects / Q000276:immunology; D017750:Animal Technicians; D000818:Animals; D000830:Animals, Laboratory; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D004306:Dose-Response Relationship, Immunologic; D004731:Endotoxins / Q000008:administration & dosage / Q000009:adverse effects* / Q000276:immunology; D005260:Female; D006801:Humans; D007114:Immunization; D008297:Male; D017056:Medical Laboratory Personnel; D051379:Mice; D008875:Middle Aged; D015999:Multivariate Analysis; D011237:Predictive Value of Tests; D011852:Radioallergosorbent Test; D012130:Respiratory Hypersensitivity / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology; D012307:Risk Factors; D012882:Skin Tests; D013223:Statistics as Topic; D017132:Workplace
chemical_list: D000395:Air Pollutants, Occupational; D000485:Allergens; D004731:Endotoxins