This study may have some limitations. First, a
cross-sectional design may restrict causal relations.
This can be addressed in a prospective cohort study.
Another limitation is that in evaluating solvent
exposure we relied on environmental monitoring
alone. Workers were in separate working environments,
which facilitated group classifi cation and exposure
assessment, but further studies should consider using
biological monitoring instead. Besides, we were not
able to calculate cumulative occupational exposure
because the information on previous levels of exposure
was not available.
We investigated the effects of mixed organic
solvents on hypertension, but not the effects of single
solvents. However, organic solvent mixtures are more
common in workplaces.