Effect of cleaning on symptoms and percieved IAQ in an office building

Many workers in an office building complained about IAQ. No moisture damage was foundin the offices, which were, however, painted and carpeting was changed. Ventilation ductswere cleaned and the supply and exhaust air vents were installed in every room. Shortly afterthe repair the workers developed symptoms. A thorough survey of IAQ including microbesand particles and volatile organic compounds was conducted twice after the repair. Betweensurveys the rooms were cleaned for 2 months twice a week with more effective practices thanbefore. The first microbial and particle measurements before the intervention cleaningsuggested that the ventilation system was partly responsible for complaints. Occurrence ofsome indicator microbes suggested moisture damage in the office. The microbial and dustconcentrations clearly decreased after the effective cleaning period. The total concentrationsof VOCs were low ranging from 19 to 220 g/m3 already before the intervention cleaning.