One of the few bright spots of the pandemic has been the dramatic increase of funding that has gone towards making schools safer. In order to make best use of this money, schools need to consider, not only having sufficient resources for the present, but also being prepared for the future.
Indoor air quality is a critical component of school safety that has long been neglected.
Why is air quality so important in schools?
The most immediate reason for improving air quality is prevention of llness transmission. Studies have shown that the vast majority of COVID outbreaks have occurred indoors, particularly in buildings with poor ventilation. And it isn’t just COVID. Building-related interventions have been shown to reduce the spread of many other airborne infectious diseases, including severe acute respiratory syndrome(SARS), Middle East respiratory syndrome (MERS), tuberculosis, measles, and the flu.
Indoor air quality will become increasingly important as climate change, increased globalization, and urbanization contribute to an environment that makes pandemics even more likely.
But the issue of air quality extends far beyond illness transmission to an array of health concerns, including a decrease in cognitive ability.
Why is pollution dangerous to children?
Air pollution is made up of a complicated combination of suspended gases, solids, and liquid particles. There are numerous toxic ingredients in this mix, including ozone, sulfur dioxide, and carbon monoxide, all of which can cause serious health issues. But, the component that appears most damaging are PM 2.5 particles.
PM 2.5, also known as fine particulate matter, generally comes from smoke, dust, and exhaust. PM 2.5 is 30 times smaller than the width of the average human hair, so small that it can remain airborne for long periods of time, and infiltrate buildings and our bodies. Ultrafine particles are even smaller, less than .1 micrometer across. Their tiny size makes them almost impossible to monitor.
PM 2.5 particles are so small that they may even be able to go straight from the nose to the brain, bypassing the blood-brain barrier. And they don’t travel alone. On the surface of these particles are a whole range of contaminants including chemical compounds and metals.
Once inside the body, PM can affect the body in a number of devastating ways. Exposure to PM2.5 has been linked to heart, lung, and brain issues and even premature death.
Children are especially vulnerable to the ill effects of air pollution. For instance, nearly one in thirteen children in the US has asthma, which is triggered by allergens commonly found in schools, and is the leading cause of school absenteeism due to chronic illness.
Outdoor pollution can penetrate into the schools, impacting neurodevelopment and academic performance and even leading to childhood cancer.
What is the current state of air quality in schools?
Most school heating, ventilation, and air conditioning (HVAC) systems are designed for comfort, focusing on controlling temperature and common pollutants. But few schools are equipped to deal with more complicated issues of illness transmission and pollution. This is especially significant because indoor air is generally 2 to 5 times more polluted than outdoor air.
Currently, most schools do not even meet the minimum standard set by the American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE) of approximately five liters of air exchanged per second per person (l/s/p). For example, in a study of 100 US classrooms, 87 had ventilation rates below recommended minimum standards.
How can we improve indoor air quality in schools?
A recent study by the Lancet Covid-19 Task Force on Safe Work, Safe School, And Safe Travel recommends that the additional funds be used to make the following infrastructure changes in schools.
Commission buildings and examine existing systems.
Commissioning is the process of checking HVAC performance to ensure that systems are operating as designed. This means that schools should receive regular inspections by trained professionals to identify and resolve building issues. Part of this regular maintenance should be the installation of sensors to monitor CO2 concentrations in real-time to ensure that ventilation systems are working properly.
Ventilate with clean outdoor air.
Recirculating unfiltered air is unhealthy, especially during a pandemic. Opening windows and doors can dilute the concentrations of airborne viruses, lowering the rate of transmission..
Use evidence-based air cleaning treatments
Recycled air should always be filtered at the highest possible efficiency for the system’s design. Airflow patterns should be regularly reviewed to ensure that sufficient airflow is maintained across the filter. Schools should also strive for a Minimum Efficiency Reporting Value (MERV) of MERV13 filtration or higher.
Use portable air cleaners with high efficiency particulate air (HEPA) filtration.
Portable air purifiers that use HEPA filters are another option for improving ventilation requirements. Portable air cleaners can significantly increase the clean air supply in a classroom, and are often a cost-effective measure for improving indoor air.
Consider other evidence-based air cleaning approaches.
If improved ventilation and air cleaning through filtration is not possible, other science based technologies such as in-duct germicidal UV lights or upper-room germicidal UV can be considered.
Looking towards the future
The pandemic has revealed many societal issues that have long been pushed to the side. School infrastructure has been chronically underfunded. The current funding provides a unique and long overdue opportunity to ensure that no child will suffer the devastating health effects or cognitive issues caused by low quality air.