[Level and characteristics of indoor air pollutants in a furniture mall in Beijing].

Concentrations of BTX (benzene, toluene and xylene), total volatile organic compounds (TVOC), formaldehyde and other carbonyl compounds were measured in different sections of a furniture mall in Beijing. The overall indoor concentrations (mean +/- standard deviation) of formaldehyde, benzene, toluene, xylene, and TVOC were (0.37 +/- 0.08), (0.04 +/- 0.03), (0.19 +/- 0.16), (0.47 +/- 0.57), and (2.76 +/- 2.18) mg/m3, respectively. Indoor concentrations of formaldehyde, xylene and TVOC were 22, 46 and 34 times higher than the corresponding outdoor concentrations respectively. Concentrations of formaldehyde, xylene and TVOC were much higher than the standard limits regulated in the national "indoor air quality standard" (GB/T 18883-2002), and the highest concentrations of formaldehyde and TVOC exceeded the standard limit 5.1 and 14.8 times respectively. Total concentration of carbonyl compounds was (689.3 +/- 94.8) microg/m3, which was 5 times higher than that outdoors. Of the carbonyls, formaldehyde and acetaldehyde were found to be the most abundant, together accounting for over 75% of the total carbonyl concentrations. Acetone, C4 carbonyls (methacrolein, methyl ethyl ketone, butanal), and hexanal also occurred at relatively high concentrations. In conclusion, indoor air pollution is serious in the furniture mall.