Air pollution is contributing to about 40,000 early deaths a year in the UK, the Royal Colleges of Physicians and Paediatrics and Child Health have said.
While the pollutants have changed over time - from coal soot to diesel vehicle emissions - the health risks remain.
Tobacco still poses the biggest indoor threat, but wood-burning stoves, spray deodorants, cleaning products, air fresheners and fly spray contribute.
Mould and mildew in poorly ventilated rooms can also cause illness.
"Being indoors can offer some protection against outdoor air pollution, but it can also expose us to other air pollution sources," the report says.
"There is now good awareness of the risks from badly maintained gas appliances, radioactive radon gas and second-hand tobacco smoke, but indoors we can also be exposed to NO2 [nitrogen dioxide] from gas cooking and solvents that slowly seep from plastics, paints and furnishings.
"The lemon-and-pine scents that we use to make our homes smell fresh can react chemically to generate air pollutants, and ozone-based air fresheners can also cause indoor air pollution."
Co-author Prof Jonathan Grigg said there was now clear evidence air pollution - largely from factories and traffic - was linked to heart disease and lung problems, including asthma. Source: BBC