The researchers found that living with smokers is the same as living in smoke-free homes in heavily polluted cities such as Beijing or London, BBC health reported.
Researchers at the universities of Edinburgh and Aberdeen said moving to smoke-free homes could have major health benefits for non-smokers.
They said there was already strong evidence to suggest that exposure to second-hand smoke is linked to a wide range of adverse health events such as respiratory and heart illness.
Accordingly, many governments have introduced measures to restrict their population’s exposure to second hand smoke within workplace and leisure settings. Fine particulate matter (PM2.5), such as fine dust or soot suspended in the air, has been widely used as a marker for second-hand smoke exposure.
Main outdoor sources of particulate matter include exhaust fumes from motor vehicles and industrial emissions, and more is known about what impact this has on health than the impact within indoor environments.
Therefore, the Scottish researchers set out to estimate the amount of PM2.5 inhaled by people living in smoking and non-smoking homes. They studied data from four linked studies carried out in Scotland between 2009 and 2013 that had real time measurements of PM2.5 in homes, and combined them with data on typical breathing rates and time-activity patterns.
Collectively, the studies produced air quality data from 93 smoking homes with a further 17 non-smoking households. Most sampling was for a 24-hour period with the exception of one study data, which was generally carried out over a period of 6-7 days.
The results showed that the average PM2.5 concentrations from the 93 smoking homes were about 10 times those found in the 17 non-smoking homes. Non-smokers living with smokers typically had average PM2.5 exposure levels more than three times higher than the World Health Organisation’s guidance for annual exposure to PM2.5.