Environmental quality in primary schools and related health effects in children. An overview of assessments conducted in the Northern Portugal

Since children are far more vulnerable than adults to the effects of air pollution and spend about a third of their day in school, strict control of indoor environments in educational buildings is paramount to prop-erly identify, manage and mitigate putative environmental risks for children. In this context, this work aimed to provide a holistic view on the outcomes obtained from the national ARIA project, which was focused on broadening the knowledge on the effects on children's health of the exposure to schools' indoor air. In particular, this work performed a comprehensive investigation of the indoor air quality (IAQ) in 20 public primary schools located in Porto (Northern Region, Portugal). This paper presents the results of the investigation along with the recently published main outcomes of ARIA on (1) the char-acteristics of the environment surrounding the surveyed buildings, and (2) the school's environment-related health effects in school-age children from the studied classrooms. The investigation consisted in an extensive assessment plan conducted in 71 classrooms to assess temperature, relative humidity, carbon monoxide and dioxide, particulate matter (PM2.5, PM10, and ultrafine particles), nitrogen dioxide, ozone, volatile organic compounds, formaldehyde, acetaldehyde, airborne fungi, bacteria and endotoxins, and investigate their respective sources, during the cold seasons of 2014-2015. A series of studies was also launched to investigate school environment-related health detriments in 916 children. The results showed that comfort and ventilation issues and/or indoor pollutant levels that exceeded recommended limits were found in a substantial number of the classrooms surveyed. The high density of occupants, deficient ventilation, soil characteristics, presence of indoor pollution sources (e.g. classroom materials and consumer products) and outdoor pollution were some of the factors that seemed to explain the high air stuffiness and/or indoor pollution load identified in classrooms. In fact, some of indoor pollutants detected, even at low exposure levels, were associated with the development of respiratory symptoms in school-age children. Moreover, results from this work have also shown that the characteristics of the environment surrounding the schools, namely the presence of green spaces and species richness, can be major determinants of respiratory health among school-age children. Overall, the body of evidence generated from the ARIA project can support new evidence-based perspectives for promotion of health in educational buildings. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

This study investigated the indoor air quality in 20 public primary schools in Porto, Portugal and found that a substantial number of classrooms had comfort and ventilation issues, as well as indoor pollutant levels exceeding recommended limits. Factors such as high occupancy density, poor ventilation, indoor pollution sources, and outdoor pollution seemed to explain the high air stuffiness and indoor pollution load in classrooms. Indoor pollutants, even at low exposure levels, were associated with respiratory symptoms in school-age children. Additionally, the characteristics of the environment surrounding the schools were shown to be major determinants of respiratory health among school-age children.