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Determining a reference value for blood cholinesterase using US Defense Department personnel.

McCurdy-SA; Henderson-JD; Arrieta-DE; Lefkowitz-LJ; Reitstetter-RE; Wilson-BW
Toxicologist 2004 Mar; 78(S-1):177-178
The use of pesticides and threats of chemical warfare establish the need for high throughput reliable standardized determinations of blood cholinesterase (ChE) as early warnings of exposure. The US Army Center for Health Promotion and Preventive Medicine (CHPPM) uses a pH method based on that of Michel for the determination of red blood cell cholinesterase levels in humans. With it they monitor approximately 25,000 DOD personnel annually. Our goal is to establish a normal range of blood ChE using pH data. Blood specimens from 991 Department of Defense personnel without a potential exposure to anti-cholinesterase agents enrolled in a required occupational health screening program were statistically analyzed. The median age was 43 years (range 18-76). 823 specimens (82.1 %) were from men. Men were on average older than women (median age 44 vs 37 years, p<0.0001, Wilcoxon test). The mean +/- SD for pH was 0.75 +/- 0.06 units. pH values were greater for men than for women (0.74 vs. 0.73, p<0.0006, Wilcoxon test). Multivariate linear regression analysis showed an association for pH with age (slope +0.0008 pH units for each year of age, p<0.001). There was a small, but statistically significant, reduction in pH associated with test date (-0.006 pH units per 100 days, p<0.001). A multiple regression model incorporating age, gender, and test date explained only 3.4% of the observed variance. The small magnitude of these effects and their minimal role in accounting for the observed variability suggest it appropriate to ignore such factors when evaluating pH data. The next step in our project is to correlate the pH values with those from the more commonly used colorimetric Ellman test.
Cholinesterase-inhibitors; Military-personnel; Pesticides; Pesticides-and-agricultural-chemicals; Chemical-warfare-agents; Exposure-levels; Humans; Red-blood-cells; Occupational-health; Statistical-analysis; Models
Publication Date
Document Type
Funding Amount
Funding Type
Cooperative Agreement
Fiscal Year
Identifying No.
Source Name
The Toxicologist. Society of Toxicology 43nd Annual Meeting and ToxExpo, March 21-25, 2004, Baltimore, Maryland
Performing Organization
University of California - Davis
Page last reviewed: March 11, 2019
Content source: National Institute for Occupational Safety and Health Education and Information Division