You exhaust me! Air pollution exposure near schools during pick-up and drop-off times

Abstract

Background

Public and healthcare practitioner awareness of climate change and the longitudinal health impacts of air pollution is growing; however, it is not always clear how to implement practical and feasible steps that individuals and communities can take to help decrease air pollution and protect children, and it can be challenging to request and enforce behaviour changes that the public associates with perceived personal inconvenience. In this context, it is important to consider common, chronic exposures that increase children’s risks, especially when straightforward solutions with minimal negative impact where significant evidence-based positive results are available.

Aims

This article provides simple tips that healthcare providers, parents, and communities can use to advocate for decreased idling in school zones to improve air quality in and around schools.

Graphical abstract

Graphical Abstract.

INTRODUCTION

Childhood exposure to traffic-related air pollution (i.e., particulate matter [PM]) is associated with exacerbations of chronic conditions (e.g., asthma) that may result in emergency department visits (1). Given the vulnerability of children to air pollutant exposure and the potential health consequences, it is important to identify effective interventions whose implementation reduces childhood air pollution exposure and prevents disease.

A key exposure issue involves transportation to and from school. Automotive (bus and private vehicle) transportation to school has increased over the last decades in North America while active school transportation, such as walking and biking, has decreased. As the proportion of automotive school drop-off and pick-up increases, air pollution concentration around schools could increase.

Studies in Canada and internationally have indicated an increase in traffic-related air pollution at school drop-off zones (2–5). This exposure ranges depending on measurement location and binning averages. One study in Australia measured PM_2.5 at school drop-off locations demonstrating median values of 28.5 μg/m³ with wide ranges (2). Another study using mobile PM_2.5 measurement at drop-off reported mean values of 53.95 μg/m³ (3). Additionally, “hot spot” peak values can range even higher with values of 80 to 100 μg/m³ in Taiwan (3) and nearly120 μg/m³ in Canada (4). Moreover, while traffic-related air pollution dissipates from the source, PM concentration may remain elevated in nearby classrooms, with one Canadian study demonstrating mean levels of PM_2.5 in classrooms during drop-off at 7.31 μg/m³ (5). These potential pollution levels experienced by children are alarming given they exceed the World Health Organization’s maximum daily and annual averages of 15 and 5 μg/m³, respectively (6).

ROLE OF HEALTH PRACTITIONERS

The role of health providers in prevention cannot be overemphasized. Safety programs have historically operated on a “3 Es” framework that consists of Education, Enforcement, and Engineering. This framework can be applied to decrease traffic-related air pollution given the evidence supporting interventions that promote these “Es” to reduce school drop-off air pollution (Table 1).

Table 1.

The “3-Es” (Education, Enforcement, and Engineering) safety approach to traffic-related air pollution at school for primary healthcare providers.

Suggested strategy	Education	Enforcement	Engineering
Decrease vehicle use	Encourage active transport	Positive reinforcement Active transport campaigns Encourage car-pooling and transit use	Encourage safe routes for active transport Develop school-based active transport programs (e.g., a “walking school bus” run by the parent advisory council) School-based air purifiers
Decrease idling	Inform parents and school transportation (e.g., bus) providers	Anti-idling activities (signage, reminders) Collaborate with school bus providers	Limit drop-off and pick-up near school buildings Move school bus stops away from air intakes

Education

Many schools are unaware of the extent or effects of air pollution during school drop-off and pick-up times (2). Encouraging active transportation to and from school could mitigate this with the added benefit of promoting physical activity. Anti-idling campaigns that educate parents, schools, and children have successfully reduced PM_2.5 concentrations at school drop-off zones using signage near schools and educational newsletters for parents (2). A trusted source educating patients, parents, and school boards may be the first step to changing behaviours.

Enforcement

Recognizing, identifying, and removing exposure can be an effective way of preventing exacerbations of respiratory conditions. Bringing the potential trigger to the attention of schools can help promote policies to reduce idling near schools that may contribute to poor health outcomes. The role of the health provider could be similar to advocating for scent-free or nut-free zones. Simply understanding the extent to which children are exposed and notifying schools could create meaningful and rapid change. Creating and enforcing policy that forbids idling in front of schools has been successful in reducing traffic-related air pollution and removing “hot spots” of very high pollution (3).

Engineering

Travel behaviour to school can influence exposure. One Canadian study showed that children who walk to school experience the least amount of traffic-related air pollution exposure (4). When feasible, children and schools should be encouraged to engage in active and safe school routes where children cannot only avoid high-pollution areas but also be more physically active (4). Engineering may also include advocacy for school-level factors including air purifiers (5) in school and school buses (4), and design/location of play structures related to drop-off locations (5). Improving air filtration, also important for COVID-19 safety, is a multiple win.

CONCLUSION

The near-daily exposure of school-age children to high levels of air pollution is concerning. Alarmingly, while tools exist to reduce this exposure, many schools are unaware of the dangers and fail to implement simple, low-cost interventions. Implementation requires strong advocacy from experts, stakeholders, and champions for child health who aim to educate, enforce, and engineer solutions to reduce children’s exposure. Within the 3E framework, each E can be successful independently; however, their synergistic effects amplify effectiveness. Central to change through this framework is the role of advocacy. Acknowledging that traffic-related air pollution can affect children with respiratory conditions and understanding that repeated exposure may contribute to increased incidence of respiratory illness for every child, regardless of apparent good health, health providers, parents, and children play an important role as advocates to ensure that primary prevention strategies are broadly adopted.

POTENTIAL CONFLICTS OF INTEREST

Outside of this work, BHR received grants from the Canadian Institutes of Health Research (CIHR) and Alberta Health Services as well as book royalties from the publisher, Wiley. BHR is also Scientific Director, Institute of Circulatory and Respiratory Health at CIHR and received travel support from CIHR to attend meetings. He was also a member of Abbott Pharmaceuticals’ Point of Care Traumatic Brain Injury (TBI) Advisory Board and a member of Canadian Agency for Drugs and Technologies in Health (CADTH)’s COVID Medical Management Advisory Board, both of which were unpaid positions. AH is a member of the editorial board. Another editor was assigned to handle the peer review of this manuscript. Outside the context of this manuscript, she also reports a CIHR Team Grant and a grant from the Lung Association of Alberta, as well as support from the American Thoracic Society and the Canadian Paediatric Society for travel costs. AH is also President of the Canadian Paediatric Society Section of Environmental Health and a Member of the American Thoracic Society Environmental Health Policy Committee. There are no other disclosures. All authors have submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Conflicts that the editors consider relevant to the content of the manuscript have been disclosed.