Table 1.

Passive smoke exposure by timing and setting among study participants (n = 57,523)

ExposureNumber exposed among
Noncases (n)Breast cancer cases (n)Entire study population, n (%)
Any lifetime exposure*47,9011,56749,468 (86)
    Any household lifetime exposure39,4611,31240,773 (71)
    Any workplace lifetime exposure27,62395828,581 (50)
    Any social lifetime exposure20,69269821,390 (37)
Any age <20 exposure*36,2861,15037,436 (65)
    Any age <20 household exposure32,4121,04033,452 (58)
    Any age <20 workplace exposure9,5032959,798 (17)
    Any age <20 social exposure11,01035611,366 (20)
Any age ≥20 exposure*39,8481,36341,211 (72)
    Any age ≥20 household exposure23,69486424,558 (43)
    Any age ≥20 workplace exposure25,94491426,858 (47)
    Any age ≥20 social exposure18,87064619,516 (34)
  • *Exposure categories are not mutually exclusive, and therefore, individual setting totals will not sum to “any exposure.”