Sp. Tsai et al., Trends in cigarette smoking among refinery and petrochemical plant employees with a discussion of the potential impact on lung cancer, INT A OCCUP, 74(7), 2001, pp. 477-482
Citations number
31
Categorie Soggetti
Envirnomentale Medicine & Public Health","Pharmacology & Toxicology
Journal title
INTERNATIONAL ARCHIVES OF OCCUPATIONAL AND ENVIRONMENTAL HEALTH
Objective: To examine trends in cigarette smoking prevalence and intensity
among petroleum industry employees over a 22-year period, from 1976 to 1997
, and to evaluate the hypothesis that the (about 20%) lower lung cancer mor
tality, when compared with the general population, among these workers is d
ue to lower average cigarette consumption. Methods: Self-reported smoking p
revalence and intensity (number of cigarettes smoked per day) data were ava
ilable from the Shell Health Surveillance System for approximately 5,400 em
ployees in the 1970s, 11,000 in the 1980s, and 8,300 in the 1990s. Data wer
e analyzed by gender, time period, and work status (production vs. staff).
Results: During the 22-year study period, smoking prevalence dropped signif
icantly in this working population. When compared with the general US popul
ation, smoking prevalence trends were very similar. For the entire employee
population, smoking prevalence was highest for women working in production
(hourly) jobs. While smoking prevalence was higher among production employ
ees than among staff employees, daily cigarette consumption was slightly lo
wer. Cigarette consumption among Shell employees was similar to that in the
US in the 1970s, but lower in the 1980s and 1990s. By applying smoking con
sumption data from the 1970s, the ratio of weighted lung cancer relative ri
sks for Shell employees and the US general population was 0.98. In other wo
rds, the lung cancer mortality rate of refinery and petrochemical employees
would be adjusted upward by 2% if one were to remove the influence of smok
ing consumption by Shell employees. Conclusions: Based on our data, it is u
nlikely that differences in smoking prevalence and intensity between refine
ry/petrochemical workers and the general population could account for the l
ower risk of lung cancer mortality reported in the literature.