Passive smoking and risk of cognitive impairment in women who never smoke.

T here is substantial evidence that passive smoking exposure is linked to a number of known risk factors for dementia, including cardiovascular disease. Previous research has also shown that even lowlevel exposure to passive smoking has a negative effect on the cognitive abilities of children and adolescents. But few studies have investigated the association between passive smoking exposure and cognitive impairment in older people, with conflicting findings in the direct effect on dementia. In this study we determined the relationship between passive smoking exposure and the risk of cognitive impairment in women.