Exposure level and influential factors of HCHO, BTX and TVOC from the interior redecoration of residences

Abstract

Although indoor air pollution caused by decoration and its consequent influential factors have been spotlighted, information regarding the effect of redecoration are still limited. Therefore, 143 bedrooms were redecorated identically by a specific company, and the concentration of formaldehyde (HCHO), benzene, toluene, xylene (BTX), and total volatile organic compounds (TVOC) were measured in order to determine the pollution level inside the redecorated sample dwellings, also to obtain the relationship between the mentioned compounds and their influential factors. The median concentration level of HCHO, BTX, and TVOC were 70, 10, and 160 μg/m3, respectively. 89.51% and 74.83% of the dwellings had adverse exposure level of HCHO and TVOC, respectively, which had the score of 40 based on IAQ indices (where 80 is “good” and 20 is “bad”). 81.82% of the dwellings were at the risk of respiratory symptoms in children, considering the fact that safe exposure limit of 8-h HCHO is 50 μg/m3 in Canada. Over 86% of the dwellings exceeded the threshold of HCHO set by U.S.Agency Toxic Substances Disease Registry based on health hazard assessments in the relevant toxicological literature. Only 0.7% of all dwellings exceeded health thresholds of TVOC at 600 μg/m3 from Portuguese and china. There was either a very low level of correlation or no correlation between pollutants, environmental factors, and architectural characteristics, such as temperature, Relative Humidity, building ages, and room volume. HCHO and TVOC concentration in low-rise residences were higher than that of high-rise residences (p < 0.01). Compared to wood flooring, TVOC concentration was higher when tile was used as the flooring material (p < 0.05), due to the use of adhesives.