The City of Bloomington measured "fairly low" particulate matter in most of the city in a dual study published earlier this month. Still, some areas of the city measured elevated concentrations.
The project, initiated by the National Oceanic and Atmospheric Administration, originally just studied urban heat islands with Bloomington as an example. It began last August.
Shawn Miya, the assistant director of sustainability for Bloomington’s Economic and Sustainable Development Department, said the city chose to enhance the heat island project by adding an air quality study focused on measuring particulate matter.
These tiny particles are composed of many different chemicals and are usually produced from automobiles, construction equipment, agricultural processes, industrial plants and wildfires. When these particles are smaller than 2.5 micrometers in diameter, they can be especially harmful to human health.
“Those fine particulates have an impact on human health,” Miya said. “Especially vulnerable populations such as children, older adults and those with asthma and cardiovascular disease.”
City officials collected data for fine particulate matter alongside temperature and humidity readings over three intervals during the day of Aug. 4, 2024. Following the initial mobile campaign, they placed air quality monitors at 10 fixed locations across Bloomington for 21 days.
Philip Stevens, associate dean for faculty affairs and professor at the O'Neill School of Public and Environmental Affairs, emphasized that the results of this study only present an overview.
“It’s only a snapshot,” Stevens said. “But it does indicate that there is spatial gradience in the concentration of these fine particulates across the city.”
For more accurate results, Stevens suggested a long-term study.
“Doing more measurements over a longer period of time would provide even more information about how these gradients change over time,” Stevens said. “And whether there are areas that consistently have higher concentrations that could have some health implications.”
Miya explained that there were elevated concentrations of particulate matter in the central, eastern and southern portions of the city.
One data collection point south of campus indicated elevated concentrations of particulate matter above 12.1 micrograms per cubic meter for six days. The Environmental Protection Agency states that there is a higher health risk whenever concentrations are above 12.1 for over 24 hours.
Still, Stevens said the results from the study are not cause for alarm. Bloomington has “fairly low” measurements of fine particulate matter, he said.
“I think what the report is showing is that the levels vary across the city,” Stevens said.
The city of Bloomington is already working to address the disparities in air quality. Miya said the city provided Canopy Bloomington, an organization managing Bloomington’s urban forest, with $50,000 to begin planting more than 100 trees in lower-income neighborhoods Crestmont and Walnut Woods.
The study also granted insight to the temperature differences between urban and rural Monroe County.
“We found that there was a 12-degree difference between Griffey Lake and our downtown area, which is really significant,” Miya said.
She explained that the city will use this data to create a climate resilience map in order to better coordinate Bloomington’s environmental initiatives.
Additionally, the city will use the data to create new green spaces.
“We're going to look to see in those hot areas and low-income areas if there's any place where the city owns that property that we can turn into a micro park,” Miya said.
Planting trees and creating green spaces will provide shade, reduce temperatures and improve overall air quality.
“We want to make sure that wherever people are walking, that the sidewalks are shaded,” she said.
They’re also considering other strategies, including grants for commercial or nonprofit buildings to install cool roofs and pavements. According to Miya, these sunlight-reflecting roofs can be up to 50 degrees cooler, while the pavements help to reduce urban temperatures.
Bloomington residents also have a part to play in the city’s environmental efforts.
“Whenever we burn fossil fuels, that is a big contributor to particulate matter,” Miya said. “We can all take part in reducing our fossil fuel consumption by investing in energy efficiency projects, in our homes, businesses, nonprofits and in our municipal government.”
In the meantime, results from the air quality study and heat watch campaign will continue to inform the city’s environmental goals.
“We care about each other and our health, and especially the health of our vulnerable neighbors who are impacted the most by climate change,” Miya said. “The air quality study and the heat watch campaign provide us with information that we can use to begin developing strategies that help us adapt to climate change.”
