Children are up to three times more likely to develop conditions like asthma and hayfever due to chemicals found in some wall paints and cleansers.
Researchers from Karlstad University in Sweden found youngsters had up to 180 per cent greater risk of developing allergies if they were exposed to chemicals known as PGEs in their bedrooms.
The study looked at the effect of PGE chemicals, which are found in some wall paints and plastic toys and packaging
Study leader Professor Carl-Gustaf Bornehag, said: 'The study shows for the first time that the concentration of PGEs, propylene glycol and glycol ethers, in bedroom air was linked to an increased risk of developing asthma, rhinitis and eczema in children.
'The increase in risk varied between 50 and 180 per cent. It was also found that a higher concentration of PGEs in indoor air was associated with children evincing antibodies (IgE) against allergens such as cats, dogs, pollen.
'Our analyses also revealed that the use of water-based paint in the dwelling, as well as water-based cleansers, was linked to a higher concentration of PGEs in bedroom air.'
The chemicals can also be found in some plastic toys and packaging.
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The researchers studied 198 preschool children with asthma and allergies along with 202 healthy controls in Varmland, Sweden.
Air samples were taken from the children's bedrooms and eight groups of volatile compounds were analysed.
The children were then examined by doctors while their parents filled in a general health questionnaire about the family's health and lifestyle.
Professor Bornehag said: 'We have previously shown that phthalates from soft PVD could be tied to allergic conditions in children.
'Now we have focused on PGEs. Among the substances identified are compounds suspected of disturbing hormones, which was also the case regarding the phthalates we studied earlier.'
Professor Bornehag said: 'Our findings once again raise the question of the health-related aspects of the use of chemicals in our everyday lives.
'Particularly when it comes to exposure in our home environments, since small children and pregnant women spend a great deal of their time there and there are many indications that exposing fetuses and infants is probably more risky.'
The scientists, whose study was published in the journal PLoS One, said further research was needed into how chemical exposure in childhood could contribute to chronic conditions.