THE DIRT: Air quality monitoring

Your family sledding trip should only leave your calves burning. But you feel it more in your chest after a smoky day in our narrow Silver Valley. Think back to the red AQI forecast on your phone. What information was it trying to convey? The Air Quality Index (AQI) is a color-coded tool to relay air pollution threats. Starting at GREEN, for good, colors warm to MAROON, for hazardous. The AQI can represent a variety of pollutants. In North Idaho, two air pollutants are monitored—PM10 and PM2.5.

The air around us contains particulate matter (PM). This term describes the microscopic solids and liquid droplets suspended in the atmosphere. These inhalable drifters can be pollen, dust, or other harmful particles. PM10 is the subgroup of these particles smaller than 10 micrometers (µm). About the size of one-tenth a grain of salt, PM10 particles can often be coughed out. PM2.5, on the other hand are tiny, 2.5µm in size. Measuring about one-20th of a strand of hair, these particles can be breathed in so deeply that they cannot be expelled. They can build up with each exposure and lead to the most risks. Associated toxins can pass directly into the bloodstream causing adverse effects.

This year, the EPA lowered the annual PM2.5 standard to reflect a better understanding of health risks associated with long-term exposures. This is one of the National Ambient Air Quality Standard (NAAQS) criteria pollutants that is monitored to help protect environmental and community health. The current primary standard for annual PM2.5 is 9.0 micrograms per cubic meter (µg/m3). This concentration of particles in the air is considered safe for most people. It corresponds with the maximum of the GREEN category from the AQI. When the average concentration rises above 9.0µg/m3 for 24 hours, there is an increased risk of short-term effects. Furthermore, when the annual average has excess days above the GREEN category, you start to see the riskier long-term effects associated with exposure to PM.

To help the community make informed choices and monitor potential health risks, a monitoring site in the Silver Valley was installed near Pinehurst Elementary School. The site features weather data collection, monitors for collecting PM2.5 and PM10 data and a NASA robot that monitors the upper atmosphere. Keeping tabs on this data with the DEQ Air Map and watching for AQI forecasting is easy! It can help you make informed decisions on how much time you and your family should be spending outdoors. Paying attention is just the beginning of protecting ourselves from poor air quality.

The Dirt is a series of informative articles focused on all aspects of cleanup efforts associated with the Bunker Hill Superfund Site. Our goal is to promote community awareness of contamination issues, to provide tools for protecting public health, and to keep the community informed of current and future cleanup projects. The Dirt is a group of committed and local experts from multiple agencies including the Basin Environmental Improvement Project Commission, Panhandle Health District, Shoshone County, Silver Valley Economic Development Corporation, and the Idaho Department of Environmental Quality.