In the most-exposed group, the risk of cognitive impairment was 44 percent higher than the benchmark group.
Factors such as age and medical condition, including a history of heart disease, that could have skewed the outcome were all taken into account.
"A similar pattern of associations was observed for never smokers and former smokers," said the study, published in the British Medical Journal (BMJ).
"Given the ongoing international policy debate on exposure to second-hand smoke, this is a topic of major public health significance."
Governments in North America, Australia and Europe have progressively enacted "smoke-free" legislation for the workplaces, bars, restaurants and other public places over the last 15 years.
Source-AFP
SRM