Washington, Oct 29 A new American study has found that nearly 60 percent of the dust that gathers inside a house comes from outside.

The research conducted by David Layton and Paloma Beamer will appear in Nov. 1 issue of ACS' Environmental Science and Technology, a semi-monthly journal.

The study has found that household dust is a mixture of human dead skin, fibres from carpets and upholstered furniture, soil brought into the house by shoes and other particles blown into the house from outdoors.

According to the authors, lead, arsenic and other harmful substances can find their way into the house through air and soil, which can be dangerous for young children who are in the habit of mouthing dust laden toys and objects.

The scientists used a computer model to monitor and evaluate the spread of contaminated soil and airborne particles into the house. (ANI)