Seasonal evaluation of outdoor/indoor air quality in primary schools in Lisbon

Abstract

The aim of this study was to evaluate the indoor (I) and outdoor (O) levels of NO₂, speciated volatile organic compounds (VOCs) and carbonyls at fourteen primary schools in Lisbon (Portugal) during spring, autumn and winter. Three of these schools were also selected to be monitored for comfort parameters, such as temperature and relative humidity, carbon dioxide (CO₂), carbon monoxide (CO), total VOCs, and both bacterial and fungal colony-forming units per cubic metre. The concentration of CO₂ and bioaerosols greatly exceeded the acceptable maximum values of 1800 mg m⁻³ and 500 CFU m⁻³, respectively, in all seasons. Most of the assessed VOCs and carbonyls occurred at I/O ratios above unity in all seasons, thus showing the importance of indoor sources and building conditions in indoor air quality. However, it has been observed that higher indoor VOC concentrations occurred more often in the colder months, while carbonyl concentrations were higher in the warm months. In general, the I/O NO₂ ratios ranged between 0.35 and 1, never exceeding the unity. Some actions are suggested to improve the indoor air quality in Lisbon primary schools.

Formaldeído em escolas: uma revisão

“…Em Portugal, a evolução sazonal da qualidade do ar de 14 estabelecimentos de ensino básico de Lisboa foi avaliada usando amostradores passivos, 40 depois de otimizadas e validadas as metodologias de amostragem e de análise. 168 O formaldeído foi detetado em concentrações significativamente mais elevadas em comparação com outros compostos carbonílicos.…”

“…Inúmeros estudos confirmaram que os COV são, em geral, encontrados em maior número e em concentrações mais elevadas nos ambientes internos do que no ar externo. 4,[39][40][41][42][43][44][45][46] Por este motivo, esta é a classe de compostos mais frequentemente estudada nos ambientes internos. 47 Dada a sua presença em inúmeros materiais de construção e produtos de uso corrente, o formaldeído é um dos COV com emissões mais elevadas em ambientes interiores, sendo frequentemente associado à SED.…”

Indoor Air Quality in Primary Schools

“…All schools have natural ventilation and there is no forced ventilation or air conditioning system in use (ventilation is done by opening doors and windows). The data studied here is part of a larger study, which has been described and analysed in previous research (Almeida et al, 2011;Canha et al, 2010Canha et al, , 2011Pegas et al, 2010Pegas et al, , 2011aPegas et al, , 2011b.…”

“…Volatile Organic Compounds and carbonyls were sampled in parallel using Radiello ® diffusive passive tubes (cartridges codes 130 and 165, respectively) for 14 consecutive days in two replicates (Pegas et al, , 2011a(Pegas et al, , 2011b. Samples were collected at a height of about 1.5 m above the classroom floor.…”

Estudo exploratorio da qualidade do ar em escolas de educacao basica, Coimbra, Portugal

“…7,9,15 There are various studies on the quality of air quality inside schools. 2,4,11,12,a However, there are few studies involving this area in Portugal.…”