[This text was written by Mònica Ubalde, Carolyn Daher, Mireia Gascon, Ioar Rivas, Jordi Sunyer and Mark Nieuwenhuijsen (ISGlobal), and was originally published in Spanish in the electronic report Respira Madrid.]
As a result of our current urban planning and transport model—which relies on dense building construction and allocating public space to private motor vehicles— children have limited independence during their daily journeys to school and families have a heightened perception of danger. Consequently, families tend to use private motor vehicles to take children to school.
This tendency has affected the environment where children spend most of their time—their schools—in ways that need to be made more visible. The quality of the air and the ways in which public space is used have repercussions that affect children’s health, physical development and brain development, as well as the maturation of their basic psychological and learning skills.
As a result of our current urban planning and transport model—which relies on dense building construction and allocating public space to private motor vehicles— children have limited independence during their daily journeys to school and families have a heightened perception of danger
The growing number of journeys to school made by private car has led, first and foremost, to a decrease in physical activity. With about 40% of children classified as overweight, Spain has one of the largest problems of childhood obesity anywhere in Europe. Obesity in children is associated with other symptoms and chronic diseases, including asthma, type 2 diabetes, sleep apnoea, cardiovascular or bone problems, and elevated risk of low self-esteem, depression and social isolation. Active travel to school and neighbourhood-based physical activity should be included in the minimum daily exercise needed to reduce the sedentary lifestyles that are directly linked to childhood overweight. In addition to preventing children from walking to school, the use of private vehicles for these daily journeys leads to more traffic, more bottlenecks at school entrances, and a school environment that is noisier, less safe and characterised by poorer air quality.
9 Out of 10 Children Breathe Polluted Air
Air pollution causes childhood asthma and impaired cognitive growth, among other conditions. There is no organ, body system or stage of life that is not affected by air pollution. However, the prenatal period and early childhood are the stages of life in which children are most vulnerable to exposure to toxic air, which affects brain development and respiratory health and increases the risk of chronic disease in later stages of life.
For example, a recent study of 915 children aged 6 to 15 years in Germany found that exposure to high levels of air pollution during infancy can affect the development of lung function into adolescence.
Two girls sitting on the benches of the planters at Escola Els Llorers (Barcelona). Mariona Gil / Barcelona City Council.
Children are particularly vulnerable to environmental exposures because they are still developing. In addition, because of their physiological peculiarities (e.g. high respiratory rate) and behavioural traits (e.g. high levels of physical activity), children may receive higher doses of air pollution than adults. High short-term exposures can have an especially large impact on children’s health. Globally, 93% of all children breathe air that does not meet the standards of the World Health Organisation, resulting in 600,000 premature child deaths each year. In the city of Barcelona, for example, nearly 50% of childhood asthma cases can be attributed to air pollution.
Globally, 93% of all children breathe air that does not meet the standards of the World Health Organisation, resulting in 600,000 premature child deaths each year
BREATHE (BRain dEvelopment and Air polluTion ultrafine particles in scHool childrEn), a project led by ISGlobal, is the largest epidemiological study in the general population to assess whether exposure to traffic-related air pollutants at school negatively affects children’s cognitive development (Sunyer et al. 2015). The key elements of BREATHE are the direct measurement of exposure in classrooms and on school playgrounds, the assessment of cognitive function developmental trajectories through repeated examinations, and the inclusion of neuroimaging.
More than half of the dose of air pollutants children breathe each day comes from exposure to road traffic on the way to school and in the vicinity of the school itself. Indoor and outdoor air pollution levels at schools generally follow the trends seen at urban background measurement stations. However, pollution levels at a school may be higher or lower than background levels, depending on the traffic conditions on specific nearby streets, thus confirming the existence of infiltration from outdoors to the indoor school environment as well as the influence of traffic emissions. This exposure, specifically to suspended particulate matter (PM2.5) and black carbon, impairs children’s working memory and attentiveness as well as their cognitive development.
More than half of the dose of air pollutants children breathe each day comes from exposure to road traffic on the way to school and in the vicinity of the school itself
More Vegetation, Less Pollution
One study, conducted at 39 schools in Barcelona, found that the concentration of traffic-related air pollutants (NO2), ultrafine particles and suspended particulate matter (PM2.5) was lower, both indoors and outdoors, in schools with more vegetation, especially those with more trees. It has also been found that children in schools with higher levels of air pollution may be at higher risk of overweight and obesity than those in less polluted environments. Walking or cycling to school is a way of integrating physical activity as a daily habit; it also has health benefits that outweigh the harms of air pollution. Choosing school routes along less polluted streets would enhance these benefits.
One study, conducted at 39 schools in Barcelona, found that the concentration of traffic-related air pollutants was lower, both indoors and outdoors, in schools with more vegetation, especially those with more trees
Since children spend a substantial portion of their day in class and on the playground, schools are among the most crucial urban spaces for ensuring children’s health, well-being, effective learning and behavioural response management, among other skills. Guaranteeing good air quality at schools is important for the benefit of children and for public health. Therefore, air pollutants in schools and the associated cognition-related health effects must be properly characterised so that preventive actions can be identified and targeted to minimise the impact of this pollution.
Children watering plants at Escola Els Llorers. Mariona Gil / Barcelona City Council.
Public spaces such as schools provide an opportunity to reconnect with nature by introducing green and blue features for the promotion of equitable health, covering different socioeconomic levels within neighbourhoods and mitigating the effects of “green gentrification”. A good strategy for equitably combatting heat, air pollution and the effects of climate change is to seize the opportunity presented by public school playgrounds and buildings—which typically boast little green space—and plant more trees, build green walls to generate shade, and add water features (fountains, water play areas). Such adaptations would have a positive impact both on social cohesion and on the physical and mental health and well-being of children and other community members granted access to these spaces.
Studies have shown that urban greenery is beneficial for mental and cardiovascular health as well as for neurodevelopment in children. However, there is still a need for scientific studies to assess the health effects of greening and, especially, the addition of water features and the adaptation of buildings in public spaces such as schools. Most of the studies that have included children have focused on the benefits of greenery in outdoor school environments in terms of increased levels of physical activity, imaginative play and development of positive relationships, and as a place for learning, restoration of attention, overall health improvement, improved performance, psychological well-being and stress reduction.
Studies have shown that urban greenery is beneficial for mental and cardiovascular health as well as for neurodevelopment in children
Scientific evidence shows that contact with natural environments stimulates creativity and influences cognitive development in children. In fact, just being able to see vegetation from inside a classroom has benefits in terms of cognition, recovery from stress and mental fatigue. “Doses of nature”, such as a 20-minute walk in a park, have also been found to improve concentration levels in children with attention deficit disorders.
Relationship Between Green Space and Health
The mechanisms behind the restorative effects of vegetation and nature have been described in two theoretical frameworks: Attention Restoration Theory (ART) and Stress Recovery Theory (SRT). These two theories support the notion that vegetation can contribute to a restorative school environment that supports children’s cognitive and affective functioning. ART asserts that vegetation captures our attention effortlessly, thereby allowing us to rest and restore our directed attention. According to SRT theory, our psychophysiological and restorative reactions to plants reflect an evolutionary mechanism whose function was to guide and support our ancestors in the process of finding food, water and shelter. In relation to SRT theory, for example, a study of 800 students from 13 Dutch universities showed that students preferred spaces featuring vegetation—both outdoors and indoors—and that they also expected outdoor green space to function better as a restorer of psychological well-being.
To make effective use of the outdoors, schools should provide children with access to the natural environment and teachers should help them develop a relationship with nature. A recent experience in five Dutch primary schools found that equipping playgrounds with green elements—grassy hills, tunnels made of tree branches, bushes, trees and garden-like parts—had a positive impact on restoration of attention, social well-being, appreciation of the playground and stimulation of physical activity.
Another study in two Norwegian schools showed that, during recess, asphalt-covered areas were more conducive to physical activity for boys than for girls, as they invited children to run around and play football, whereas a rural school playground, which allowed children to play in a small forest, was more attractive for girls than for boys. A recent study in Finland showed that biodiversity interventions in daycare playgrounds significantly improved children’s immune systems in a very short time, as the children developed a greater diversity of protective gut and skin microbiota than children at daycares with standard playgrounds (Roslund MI et al. 2020). In addition, vegetation at schools and playgrounds in general can provide benefits such as noise reduction, temperature decrease, energy savings, biodiversity enhancement and aesthetic value.
Transforming School Environments Into Child Health Protection Areas
In the 2020s, we can expect to see an uptick in active travel to school as well as traffic bans during drop-off and pick-up times. The areas around schools will be protected, helping children become healthier and smarter. The Spanish National Centre for Environmental Education (CENEAM) coordinates the Mobility and Childhood Seminar working group, which includes professionals from the fields of urban planning, education, mobility management, road safety and public health, as well as representatives of various government bodies, universities, research centres, consulting firms and civil-society organisations (environmental, volunteering, educational, etc.) that are involved in the development of policies and programmes aimed at promoting active, safe and independent mobility for children.
The group has proposed a ten-point list of measures to transform school environments into child health protection areas:
- Replace parking areas within school grounds with open areas and playgrounds.
- Provide secure parking areas for bicycles, scooters and skates at all schools to encourage active mobility.
- Revegetate school grounds with trees and plants that provide shade, coolness and colour while improving air quality and dampening noise.
- Restrict parking and traffic in the surrounding streets, especially in the immediate vicinity of school entrances.
- Strictly monitor and enforce traffic regulations at pick-up and drop-off times to ensure that the school environment is a safe and harmonious place.
- Prioritise pedestrian and cyclist mobility on the surrounding streets by designating car-free access corridors, adding vegetation and water features, and creating recreational, social and play areas in public space near schools.
- Integrate measures designed to create safe and healthy school environments into municipal urban planning documents.
- Incorporate specific traffic-restriction and traffic-calming measures for school environments into sustainable urban mobility plans.
- Encourage a widespread shift towards the 30 km/h model in urban areas, with the aim of reducing traffic speeds on all city streets.
- For the benefit of children and the entire community, prioritise proximity as a fundamental criterion for school catchment areas and reverse the trend towards citywide catchment areas, which have had the negative effect of increasing the number of daily journeys by car.
Many cities have started making plans to improve air quality at schools. One good example is London, home to one of the most ambitious air-quality improvement plans. In addition to unveiling the world’s first ultra-low emission zone (ULEZ) in central London in April 2019, the mayor of London announced that 50 primary schools located in areas exceeding legal NO2 limits would be audited to identify key interventions to reduce children’s exposure and that a pollution awareness education programme would be introduced at each school.
The ten-point list of measures proposed by the Mobility and Childhood Seminar (entornosescolares.es)
In Spain, cities such as Castellón, Valencia and Barcelona have recently launched urban projects to guarantee safer and healthier school environments. Castellón’s pilot project aims to limit private vehicle access to schools by closing streets to traffic in the vicinity of school entrances and exits. The city of Valencia plans to create “buffer zones” around nursery and primary schools by widening pavements, using paint and street furniture, and reallocating space previously dedicated to motor vehicles for pedestrian use. In 2020, Barcelona launched a project called Protegim les escoles (“Let’s protect the schools”), which will run through 2023 and will affect 200 schools throughout the city. The aim is to make school environments healthier and safer, with better air quality, meeting spaces, fewer accidents and less noise. The project includes three types of measures: i) traffic calming (fewer vehicles and slower speeds); ii) improving liveability (expansion of green spaces and addition of street furniture), and iii) enhancing visibility (better signage and lighting).
Moreover, through the Patios x Clima programme, cities in various autonomous communities, including Andalusia, Aragon and Catalonia, are developing projects to (re)naturalise school grounds through participatory processes . The aim of the programme is to support the creation of learning spaces with natural land cover and integrate climate action into school curricula, while helping to increase biodiversity, build resilience against the effects of climate change and improve environmental conditions in urban settings.
Schools provide a strategic opportunity for intervention in cities and represent a space for social, regional and health equity. All children go to school; therefore, if we intervene in a city’s schools, we give all children an opportunity to reap the benefits.
Schools provide a strategic opportunity for intervention in cities and represent a space for social, regional and health equity
The participation of citizens, the educational community, families, children and the scientific community in identifying needs and in the co-creation, implementation and assessment of solutions to improve health and well-being in cities and schools requires willingness and engagement on the part of government bodies and multiple sectors.
Together we can ensure that our schools are a great resource, not just for education but also for the health and well-being of the entire community.