Effect of Building Materials and Ventilation on Indoor Air Pollution by Formaldehyde.

The effect of building materials and ventilation on the indoor formaldehyde concentration was studied in three houses built by the same company. Formaldehyde in indoor air was adsorbed on DNPH-cartridge by suction using a diaphragm air pump, eluted with acetonitrile and determined by high performance liquid chromatography. Formaldehyde emission from various building materials was determined by the desiccator method defined in Japanese Industrial Standard A5908. In the case of the house built using flooring emitting a considerable amount of formaldehyde, concentration of formaldehyde in indoor air was higher than that of the Japanese guideline, 100 μg/m3 even after one year. When the house was built with the building materials ranked the F1 (average value lower than 0.5 mg/l) grade, which is defined as the highest rank by Japanese Agricultural Standard, formaldehyde concentration in indoor air did not exceed the guideline value even just after the construction. Indoor formaldehyde concentration under unventilated conditions was 1.5 to 3 times those under mechanical ventilated conditions. These results indicated that indoor air pollution by formaldehyde was dependent on the building materials and ventilation rates.