SMOKING, OCCUPATION: EITHER, NONE, BOTH? Tee L. Guidotti Department of Environmental and Occupational Health School of Public Health and Health Services The George Washington University Medical Center

A fundamental problem in occupational medicine is distinguishing between effects of smoking and effects of occupational exposure  cancer: lung, larynx, pancreas, bladder  heart disease  airways disease  peripheral vascular disease

Smoking and Occupation  confounding in occupational epidemiology  rebuttal in presumptions (scheduled occupational diseases)  individualizing risk profile  confuses impairment (disability) assessment  interactive effects  wellness programs

Many ways in which smoking and occupation may be trade-offs:  smoking may be related to job  smoking may be related to SES  smoking may be interactive with occupational exposure as causes  smoking may contribute proportionately to impairment

Smoking related to the job:  bartenders, sales, drivers  socialization  jobs of high intensity, concentration  jobs with noxious odor  delivery of toxic substances –lead –polymer fume fever

Smoking related to SES:  smoking habit concentrated in lower SES, educational attainment  higher prevalence of smoking  more cigarettes consumed  higher nicotine-content of cigarettes  lower rate of cessation  hazardous occupations concentrated in lower SES

Smoking as a confounder: overrated Example: A population with 40% smokers (x) SMR 200 = RR 2.0 = O/E O = 1(1-x) + 5 (x), x = 1.25, or 125% E 1 (0.6) + 5(0.4) Conclusion: to double the risk as a result of confounding alone, there would have to be more smokers than there are workers.

Smoking is known to be interactive with several occupational carcinogens. Best documentation:  asbestos  radon daughters  silica

Smoking and apportionment:  apportionment of causation - population-based - individual care - interaction  apportionment of impairment