Using Low-Cost Air Sensors in Schools Can Inform Decision-Making
Measuring air pollution from wildfire smoke at schools and child care settings could help staff make informed decisions that can reduce children’s exposure to smoke. Researchers at the University of Washington partnered with four Washington state schools in areas frequently affected by wildfire smoke to test a process for measuring in-school air pollution.
“Children are especially vulnerable to health impacts from air pollution because they breathe in more air relative to their body weight compared to adults, their lungs are still developing, and they are often very active,” said lead researcher Orly Stampfer, Ph.D., now at the Washington State Department of Health (WA DOH). “Measuring air pollution during wildfire smoke events could help school and child care staff determine whether to adjust activities to help protect children from harmful exposure.”
The research team examined whether and by how much air pollution measurements varied across rooms within the same school, and how indoor air quality compared with outdoor air quality during a wildfire smoke event. Results of the study are published in a May 2024 paper.
Setting up Sensors and Collecting Measurements
Researchers worked with school staff to determine where to place sensors inside the schools. They used Purple Air sensors because they are low cost and easy to install. Staff identified priority areas to measure where students would spend the most time, such as classrooms and the gym. The gym is particularly relevant because doing vigorous physical activity in the event of poor air quality can be particularly risky to children’s health. Staff also identified areas where they expected air quality to vary because of differences in ventilation and air filtration.
The researchers’ findings indicated that air quality readings varied widely across rooms within the same facility. This showed that taking measurements in multiple locations, as would be done with a handheld sensor or multiple sensors throughout a school, gives the clearest picture of children’s risk of exposure to air pollution.
The team also installed one outdoor sensor at each school. Outdoor and indoor data were used to calculate the ratio of indoor to outdoor fine particulate matter concentrations, which is a common method of assessing variability in indoor air quality.
(Left) Setting up air monitors in a classroom. The item on the wall to the top left is a Purple Air sensor. The metal item on the right is an impactor. The plastic box contains an air pump for the impactor. (Right) Outdoor air monitoring set up at a school. The item on the wall to the top right is a Purple Air sensor. The metal dome on the left is a rain shield protecting two impactors. The white plastic box contains air pumps for the impactors. (Photos courtesy of Orly Stampfer)
Since setting up multiple sensors may not be practical for schools due to financial or other reasons, the research team used their data to simulate the use of a handheld sensor that staff could use to take measurements while walking around a school, which would be a likely way school staff would take measurements on their own. Based on their findings, the team recommends that if a school is going to rely on handheld sensors for a general understanding of their indoor air quality, staff should take measurements using handheld sensors multiple times throughout the wildfire smoke event. For decisions about activities happening in the very near future, such as deciding at the last minute whether to have outdoor recess, current handheld sensor data can be useful.
The team also examined how well historical measurement data predicted air quality over the next hour. They compared the average of either 3 hours or 10 minutes of measurement data to air quality over the next hour. Indoors, the average from the 10 minutes before the hour predicted air quality over the next hour better than the 3-hour averages. Outdoors, 10 minute and 3-hour data predicted the next hour similarly. This shows that decisions about air quality indoors are best made with the most recent sensor readings.
“Air quality during wildfire smoke can sometimes be stable, but also can change substantially over a short span of time,” stated Stampfer. “When using sensors to inform decisions about children’s activities, recent, short-term measurements can be really helpful to make decisions about activity location or intensity for activities happening in the next hour.”
Developing a Toolkit for Air Quality Measurement in Schools
The study’s results have already informed guidance from WA DOH on using low-cost sensors to support decision-making during wildfire smoke. While guidance on using low-cost air sensors exists from sources such as the Environmental Protection Agency (see also the July 2024 PEPH mini article on EPA reports on using low-cost sensors), the guidance from WA DOH is specifically tailored to child and youth settings and is meant to be more accessible to school and child care staff.
The team has previously interviewed school staff about their perceptions on using air sensors to make decisions to protect children’s health. Results indicated that schools may have limitations as to what type of sensors they can use, due largely to cost considerations, but also related to the time to use and read the sensors. These perceptions informed the current study, particularly the use of low-cost sensors, and simulation of walkaround measurements.
Stampfer will continue working with the air quality team at WA DOH and plans to use the results of those interviews when developing toolkits for schools and child care settings.
“Our goal is that the toolkit will provide guidance on selecting and using sensors, as well as interpreting sensor measurements to help inform decisions,” added Stampfer. “This supports the overall aim to reduce children’s exposure to poor air quality from wildfire smoke.” Listen to the July 2021 PEPH podcast to learn more about children’s health and wildfire smoke.
Listen to the July 2021 PEPH podcast to learn more about children’s health and wildfire smoke.
Educational Video Explains Environmental Public Health to Students and Community Members
The NIEHS-funded Environmental Health Sciences Core Center at Oregon State University produced a short video to introduce the field of environmental health to students and community members. The video summarizes the link between human health and the environment and briefly describes how professionals work to understand and reduce human exposure to contaminants and other environmental hazards. The video also gives information on categories of contaminants and hazards and how people can be exposed to them. The center supports community-engaged research to understand what people are exposed to in their homes, workplaces, schools, and communities. The center’s other videos describe in greater detail how scientists study contaminants in the environment and how people can be exposed to them.
New Heat and Health Index Identifies Areas At-Risk for Heat-Related Illness
The Department of Health and Human Services recently released the Heat and Health Index (HHI), an online tool for identifying communities likely to experience negative health effects from heat. The HHI shows data by ZIP code using historical temperature figures, information on heat-related illness, sociodemographic characteristics, and features of the area’s natural and built environment that influence heat-related outcomes. Each ZIP code is assigned one overall HHI ranking, as well as rankings for each factor that influences the HHI. Rankings are shown as percentages. For example, a community with a 92% ranking is more vulnerable to the impacts of heat than 92% of other communities in the country. Users can access the tool to make informed decisions for their communities. For example, public health officials and policymakers will be able to identify areas most at risk for the negative effects of heat. They can then prioritize actions such as increasing tree canopy cover and access to air conditioning.
Use Cases and Toolkits on Sustaining Community Partnerships
The Community Engagement Alliance Consultative Resource (CEACR) has been building a toolkit for community partnerships, which are the backbone of successful community-engaged research. CEACR, supported through the NIH Community Engagement Alliance program, is a vehicle for providing NIH-funded researchers with best practices in community-engaged research approaches to address health disparities and inclusion in research. In a recent case study, CEACR highlighted staff from the West Virginia School of Osteopathic Medicine Center for Rural and Community Health who partnered with community-based organizations to address population health and inequities, providing services and conducting research that meets the specific needs of communities. For example, in response to a devastating flood in 2016, the center helped provide disaster relief with a county-wide task force. The center hosted meetings, offered its space, and connected community-based organizations with resources in response to the catastrophe. When the COVID-19 pandemic hit, the task force mobilized to host vaccine clinics, distribute food donations, and address other disparities caused by the pandemic. The task force’s responsiveness to community needs created a strong foundation of trust and reciprocity with community members, which can support future community-engaged research. Read more about how the center grew and sustained community partnerships and access toolkits from the program on creating trustworthiness and research reciprocity and best practices for community partners compensation.
