Table 1—

Demographic characteristics of workers at the four plants studied

Workers nCaucasian %Male %Ever-smoking %Age yrs
Workplace A16080.65853.843.5±11.6
Workplace B21595.46872.635.8±9.4
Workplace C23674.23937.046.4±8.3
Workplace D52883.34861.432.8±11.6
  • Data are presented as mean±sd, unless otherwise stated.