Distribution characteristics of formaldehyde in newly decorated rooms in Ningbo, Taizhou and Wenzhou City, China
Kong, Q; Li, W; Huang, W; Chen, L; Yao, J
The indoor air samples taken from 768 newly decorated rooms in Ningbo, Taizhou and Wenzhou between November 2014 and October 2016 were analyzed to detect the concentration of formaldehyde, benzene, toluene, ethylbenzene and xylene. Meanwhile, the temperature, relative humidity and air pressure of those rooms were also recorded. The results showed that the formaldehyde concentration ranged from 0.000476 to 0.789 mg/m(3), with the mean concentration of 0.136 +/- 0.116 mg/m(3). 47.9% of the rooms exceeded the permitted formaldehyde concentration defined in Chinese national standard for indoor air quality (GB/T 18883-2002). Significant positive correlations were found between the formaldehyde and temperature (r=0.358, P<0.01), humidity (r=0.128, P<0.05), and the significant negative correlation was found between the formaldehyde and air pressure (r=-0.291, P<0.01). The highest formaldehyde concentration was observed in June and July, which could be due to the high temperature and humidity in these two months. The formaldehyde concentration in the drawing rooms and bedrooms was significantly higher than that of classrooms and halls. Besides, no positive correlations were found between the formaldehyde and benzene, toluene, ethylbenzene and xylene, suggesting that they might come from different sources.