Ninety percent of homes in Shanghai are suffering from an increasing amount of indoor air pollution caused by house refurbishing and decorations, a latest survey said on Tuesday.

The Shanghai Association for Environmental Protection said it randomly inspected 95 local homes and found concentrations of formaldehyde exceeded national standards in 85 of them. The worst example is that one of these homes suffers 1.88 milligrams of formaldehyde in every cubic meter, marking 20 times over the national standard limit.

Concentrations of other harmful pollutants like TVOC, known as "total volatile organic compounds" were also found in 79 of these houses, the publicly released report added.

Li Wei, vice Secretary of the Shanghai Association for Environmental Protection, said TVOC, although often colorless, odorless and tasteless and are ignored by residents, are detrimental to people's ganglia, liver, kidney and blood system. Formaldehyde, which, however, has a very pungent odor, can cause severe health problems such as respiratory difficulties and skin irritation.

These harmful compounds, according to experts, are commonly found in building materials, paints, detergents and carpets, ranging from both famous brand names and lesser known products.

Li Wei strongly urged people to be very cautious when choosing companies for home renovations. For those who have already had their homes heavily renovated, the expert advices them to keep their windows and doors often open so that the harmful elements can easily get volatile.