Abstract
Indoor air pollution by chemicals was examined in 105 residences, for which final construction (including renovations) had been completed at least half a year earlier, in Osaka from June 2003 to January 2004. The airborne compounds were collected for 24 hours under normal living conditions. Collected nitrogen dioxide and formaldehyde were measured using the colorimetric method while 38 volatile organic compounds (VOC) and 39 semivolatile organic compounds (SVOC) were analyzed using gas chromatography/mass spectrometry. The median concentrations of nitrogen dioxide (35μg/m3), formaldehyde (31μg/m3), toluene (22μg/m3), and ethylacetate (12μg/m3) were relatively high among the compounds studied, and high concentrations of α -pinene (maximum: 1800μg/m3) and p-dichlorobenzene (1770μg/m3) were found in several residences. The concentrations of p-dichlorobenzene alone exceeded the indoor guideline values of Japan in 10% of the examined residences. The indoor concentrations of formaldehyde and nitrogen dioxide were significantly higher in winter than in summer. The indoor concentrations of di-n-butylphthalate and di (2-ethylhexyl) phthalate were high among SVOCs, and the concentrations of many phthalates and phosphates were significantly higher in summer than in winter. S-421, a synergist, was found in indoor air of a high 90% of the residences. Thirteenfungicides and insecticides containing metoxadiazone, which was not known as an indoor air pollutant, were found in the residential air samples.
