An increasing number of complaints related to time spent in artificially ventilated
buildings have been progressively reported and attributed, at least in part, to physical
and chemical exposures in the office environment. The objective of this research was
to investigate the association between the prevalence of work-related symptoms and
the indoor air quality, comparing a sealed office building with a naturally ventilated
one, considering, specially, the indoor concentration of TPM, TVOCs and the main individual
VOCs.
A cross-sectional study was performed to compare the prevalence of sick building syndrome
(SBS) symptoms among 1736 office workers of a sealed office building and 950 of a
non-sealed one, both in Rio de Janeiro's downtown. The prevalence of symptoms was
obtained by a SBS standardized questionnaire. The IAQ of the buildings was evaluated
through specific methods, to determine the temperature, humidity, particulate matter
and volatile organic compound (VOC) concentrations.
Upper airways and ophthalmic symptoms, tiredness and headache were highly prevalent
in both buildings. Some symptoms were more prevalent in the sealed building: "eye
dryness" 33.3% and 27.1% (p: 0.01); "runny nose" 37.3% and 31.3% (p: 0.03); "dry throat"
42% and 36% (p: 0.02); and "lethargy" 58.5% and 50.5% (p: 0.03) respectively. However,
relative humidity and indoor total particulate matter (TPM) concentration as well
as total volatile organic compounds (TVOCs) were paradoxically greater in the non-sealed
building, in which aromatic compounds had higher concentration, especially benzene.
The analysis between measured exposure levels and resulting symptoms showed no association
among its prevalence and TPM, TVOCs, benzene or toluene concentration in none of the
buildings.
Other disregarded factors, like undetected VOCs, mites, molds and endotoxin concentrations,
may be associated to the greater prevalence of symptoms in the sealed building.