Elevated fungal concentrations measured in dwellings on higher
floor levels (p ¼ 0.02) contrast with results of [49], who found the
highest levels of fungi on the ground floor. The difference might be
explained by different building characteristics in our study
compared to [49]. In Denmark, the Danish government released the
“The Building Act of 1856,” legislating a thinner exterior building
wall and increasing floor levels of the building. The thin uninsulated
building exterior walls might have increased the risk of water
condensation in dwellings and thus enhanced the growth of fungi
on the wall surface. It may also be speculated if the roof structures
are a significant source of fungal spores. Finally, the apartments are
not vertically airtight and the apartments at higher floor levels are
e because of the “stack effect” e expected to have a transfer of air
from apartments below to account for much of their air exchange.
There may be an accumulation of mold spores in the transferred air
as it moves from one floor to the next.