Objective To examine the association between a biomarker of exposure to secondhand smoke (salivary cotinine concentration) and cognitive impairment. Design Cross sectional analysis of a national population based study. Setting Stratified random sample of households throughout England. Participants 4809 non-smoking adults aged 50 years or more from the 1998,1999, and 2001 waves of the Health… Continue reading Exposure to secondhand smoke and cognitive impairment in non-smokers : national cross sectional study with cotinine measurement