Resumo (PT):
Abstract (EN):
Children represent one of the most vulnerable groups in society. The detailed characterization
of pollution (both indoors and outdoors) of schools is of great importance, since it may allow
preventing potential risks to children health. Yet the information related to carcinogenic
compounds, such as some polycyclic aromatic hydrocarbons (PAHs) in child educational
settings is very limited. Thus the aim of this work was to assess indoor and outdoor levels of
PAHs at Portuguese preschools (3–5 years old children) in urban areas with emphasis on
carcinogenic compounds, and to identify the main sources of indoor PAHs.
Eighteen PAHs (16 considered by USEPA as priority pollutants, and dibenzo[a,l]pyrene and
benzo[j]fluoranthene, the latter recommend EU Directive 2008/50/EC) were collected during 45
days of spring 2013 at two preschools (PS1, PS2) situated in two different (and distant from
each other) urban areas in north of Portugal. Nine carcinogenic PAHs were included:
benzo[a]pyrene (known carcinogen) and other 8 probable (benz[a]anthracene,
dibenz[a,h]anthracene, dibenzo[a,l]pyrene) or possible (naphthalene, chrysene,
benzo[b]fluoranthene, benzo[k]fluoranthene and indeno[1,2,3-c,d]pyrene) carcinogens. PAHs in
PM2.5 (particulate matter with aerodynamic diameter < 2.5 m) were simultaneously collected
both indoors (classroom, playrooms) and outdoors (playground and preschool yards).
Quantification of PAHs was performed by microwave-assisted extraction combined with liquid
chromatography with fluorescence and photodiode array detection. Total levels of 18 PAHs
(ΣPAHs) were 2.6 and 3.2 higher in indoor and outdoor air of PS1 than at PS2. Compositional
profiles were though similar at both preschools with 5–6 ring PAHs being the most abundant.
Dibenz[a,h]anthracene and benzo[b]fluoranthene (both class 2A carcinogens) were the
predominant individual PAHs at both preschools. Nine carcinogenic compounds (ΣPAHscarc)
accounted for 73 and 74% of indoor particulate PAH content at PS1 and PS2, respectively;
outdoors the corresponding ΣPAHscarc composed 66% and 71% of ΣPAHs. Analysis of I/O ratios
of ΣPAHscarc suggested that outdoor emissions were a significant contributor to indoor
carcinogenic PAHs at both schools. ΣPAHscarc exceeded the recommended EU guideline value
of 1 ng m–3
(100% of days at PS1, both indoors and outdoors; >65% samples at PS2) for the
total content in PM10 averaged over a calendar year. Therefore, in order to prevent risks to
children health it necessary to establish and implement target values of carcinogenic
components in indoor particles of smaller sizes (i.e. PM2.5).
Language:
English
Type (Professor's evaluation):
Scientific
No. of pages:
5