Regarding the sewing workrooms, photocopy and take away food shops, we obtained values of the same order of magnitude or less. By the other hand, using the criteria of WHO and U.S. EPA, LCR values for benzene, chloroform and trichlorethylene for indoor air in the electromechanical repair and car painting center are unacceptable. The same goes for chloroform levels in the chemical analysis laboratories. LCR values for other indoor environments studied are within the range of acceptability.