not really known (Jones, 1999). Some studies found that there were several related risk factors for these symptoms such as the number of person inside thework place area, type of job performed,workplace area and conditions, building design and age (Bornehag
et al
., 2001;Gyntelberg
et al
., 1994; Teeuw
et al
.,1994; Mendell, 1993). The prevalence of SBS symptoms was associated with thelevel of indoor air pollutants (IAP) and the