Chlorpyrifos exposure and biological monitoring among manufacturing workers.
OBJECTIVE
To use biological monitoring data to evaluate the soundness of job based exposure classifications.


METHODS
The authors studied 52 chlorpyrifos manufacturing workers and 60 referent workers to compare chlorpyrifos exposure estimations from job titles and work areas to urinary excretion of 3,5,6 trichloro-2-pyridinol (TCP), a metabolite of chlorpyrifos. Work history records and industrial hygiene monitoring data were used to establish cumulative interim exposure. Chlorpyrifos exposure during the study year was assessed biologically by urinary excretion of TCP.


RESULTS
Exposure as measured by three urinary TCP samples was significantly higher among the chlorpyrifos workers (188 microg/l) than it was for the referent subjects (7 microg/l). Urinary TCP also correlated well with specific exposure categories of negligible (0.73-1.98 mg/m3 days), low (1.99-4.91 mg/m3 days), and moderate (4.92-15.36 mg/m3 days). The weighted Kappa coefficient was 0.80 (95% CI 0.72 to 0.87) for the mean TCP over the study period.


CONCLUSIONS
The estimates of chlorpyrifos exposure based on job classifications and industrial hygiene measurements were significantly related to urinary TCP excretion, indicating that the ambient estimates are useful for providing exposure estimates among chlorpyrifos manufacturing workers.
The Dow Chemical Company, Department of Epidemiology, Midland, MI 48674, USA. cburns@dow.com
C J
CJ
Burns
D
D
Garabrant
J W
JW
Albers
S
S
Berent
B
B
Giordani
S
S
Haidar
R
R
Garrison
R J
RJ
Richardson
D000328:Adult; D016022:Case-Control Studies; D004390:Chlorpyrifos / Q000032:analysis*; D004784:Environmental Monitoring / Q000379:methods / Q000592:standards*; D006801:Humans; D007221:Industry; D007587:Job Description; D016273:Occupational Exposure / Q000032:analysis*; D011446:Prospective Studies; D011728:Pyridones / Q000652:urine; D012015:Reference Standards
D011728:Pyridones; C012587:3,5,6-trichloro-2-pyridinol; D004390:Chlorpyrifos