Objective To investigate the relation between the formaldehyde content of newly decorated houses and the time after decoration finished, which will offer an important reference to housing corporations and household. Methods The formaldehyde contents of newly decorated houses in Maoming were analyzed by colorimetry, Mar-Aug, 2003. Results The formaldehyde content in house A, in which the floor was compound floor boards, was higher than that in house B, in which the floor was wearable bricks. The formaldehyde content was not only related to the time after decoration finished, but also to the air temperature. After decoration finished, it must take half a year that the content of formaldehyde would meet the national standard limit. In consecutive testing, it was found that the content of formaldehyde would increase a little as the air temperature increased. Conclusion It must be attached importance to the formaldehyde content in the house floored with compound boards. It will need 6 months at least that the content of formaldehyde meet the requirement of the national standard after the newly house decoration.

Aim To explore the effect of chemical hypoxia-mimetic agent,cobalt chloride(CoCl2)on inflammatory reaction in human keratinocytes(HaCat cells).Methods After HaCat cells were treated with CoCl2 at different concentrations to set up a chemical hypoxia-induced cell model of skin injury,cell viability,intracellular reactive oxygen species(ROS),mitochondrial membrane potential(MMP),the levels of both interleukin 6(IL-6)and interleukin 8(IL-8)as well as the expression of heme oxygenase-1(HO-1)were detected.Results The viability of HaCat cells was reduced by CoCl2 at the concentrations from 500 to 3 000 ?mol?L-1,and the higher CoCl2 doses,the lower cell viability was.CoCl2 induced oxidative stress reaction(increasing ROS production and decreasing MMP).CoCl2 induced inflammatory reaction,enhancing the release of IL-6 and IL-8.CoCl2 at concentrations from 1 000 to 3 000 ?mol?L-1 upregulated HO-1 expression in HaCat cells.Conclusion CoCl2 induces not only oxidative stress,but also inflammatory reaction,increasing the release of both IL-6 and IL-8,as well as HO-1 expression.