In the recent decades many studies have been carried out in
children’s dwellings to study indoor air quality, but children’s
dwelling is not, however, their only microenvironment; the most
important indoor environment for children and their primary place
of social activity is the nursery, and up till now indoor environment
quality in this place has been poorly documented (Roda et al., 2011).
In fact, and as far as known, there are only a few studies published
concerning the indoor air quality in nurseries, particularly
regarding PM measurements. Fromme et al. (2005) analysed
respirable PM and elemental carbon levels in the indoor air of
apartments and nursery schools in the urban area of Berlin (Germany),
and found that the outdoor motorway traffic was correlated
with the indoor air in the studied nurseries. However, only 1-day
measurements were performed (sampling time from 7 to 8 h) and
the samples occurred merely in one place per nursery. Yang et al.
(2009) characterized the concentrations of different indoor air
pollutants, including PM10, within Korean schools and nurseries
and concluded that, in average, children were more exposed to PM
inside nurseries than outdoors and suggested that increasing
ventilation rate could play a key role to improve indoor air quality
in nurseries. Although measurement campaigns were performed
during summer, autumn and winter, and it has had into account the
building age, this study did not performed measurements in the
lunch rooms neither in different floors inside each studied building,
and only considered the PM10 fraction. Wichmann et al. (2010)
studied the extent of infiltration of PM2.5 (as well as soot and
NO2) from outdoor to indoor in the major indoor environments
occupied by children (10 preschools, 6 schools and 18 homes) in
different locations (city centre, suburban area and background),
and found that, despite outdoor infiltrations, PM2.5 concentrations
in these indoor environments were mainly due to indoor sources.
However, this studywas limited to places occupied by children over
6 years old and measurements were only made for PM2.5 fraction
and in one classroom per preschool. More recently, Yoon et al.
(2011) studied 71 classrooms in 17 nurseries (preschools) and
searched for indoor air quality differences (several pollutants
including PMTotal and respirable particulates) between urban and
rural ones, and confirmed that the PM concentrations indoors were
higher than those in outdoor, and also that those in urban areas
were higher than in rural areas. Lack of comparative analysis