Mike Hannigan's research group has worked on many different air quality projects spanning various applications and pollution concerns. In all our work, we strive to develop low-cost solutions for monitoring and reducing exposure to air pollutants. We ultimately hope that by quantifying pollution issues, our research empowers those working to improve their air quality, whether through policy, technology, public health measures, or other avenues. The Hannigan Lab is especially motivated to study air pollution issues that intersect with environmental justice and clean energy solutions. As such, much of our research is in partnership with local community organizations.


Read more about specific projects below, or see the list of current projects to the right.

Spatial Variability Projects

One of the benefits of using low-cost air quality measurement devices (such as U-Pods and Y-Pods) is the ability to deploy many of them in a small spatial area to quantify the variation of air pollutants in a very localized setting. The use of low-cost electrochemical sensors makes localized studies financially possible, as compared to reference sensors which are deployed at much higher spatial scales. Colocation and calibration procedures developed by the Hannigan group help to convert the raw signal data from low-cost sensors into concentrations of pollutants. These calibrations also take into consideration sensor error and bias in order to produce meaningful results.


The lab has conducted spatial variability projects in LA and Boulder. The goal is to use low-cost data to develop a better understanding of how pollutants vary within a city and how they relate to different meteorological parameters and land use patterns. These findings could be useful to regulatory agencies or air quality professionals in order to help them reduce harmful pollutants, address environmental injustice within cities, and notify citizens of times of day and locations of dangerous pollutant levels.

Our Spatial Variability Projects include: 

  • Sensors for Community Air Quality Assessment: The purpose of the project is to study ground-level ozone in the LA basin, an area with a notoriously high number of exceedances of the NAAQS (National Ambient Air Quality Standard) specified by the EPA. Ozone has negative effects on human and plant health. More.

  • Boulder County Air Quality using Sensors: The purpose of the project is to study the small-scale spatial variability of ground level ozone in Boulder. The Denver-metropolitan and North Front Range region (including Boulder) was designated a nonattainment area for ozone by the EPA in 2012 based on 8-hr averaged ozone concentrations exceeding the NAAQS (National Ambient Air Quality Standard) for ozone. More.

  • Community Air Quality in Oil and Gas Development Basins in Colorado: In this group of studies, U-pod Air Quality Monitors are used to measure several atmospheric trace gases in two oil and gas production basins via spatially distributed continuous measurements. More.

  • Landfill Methane Emissions Monitoring: Methane is an exceedingly potent greenhouse gas emitted from landfills. In this project, we use a dense network of stationary air quality monitors alongside meteorological instrumentation to measure the spatiotemporal variability of EPA-regulated methane emissions from active, real-world landfills. More.

  • ASPIRE PM2.5 Characterization in Salt Lake County: On a clear day in Salt Lake County (SLCo) you can see for miles—from the Wasatch Front in the east to the Oquirrhs in the west. However, during wildfires, inversions, and other periods of high air pollution, it may be hard to even see down the street. The ASPIRE project will investigate SLCo’s air pollution and how it affects health. More.

Combustion Emissions Assessment Projects

According to recent reports, nearly three billion people cook food and heat their homes with open fires or cookstoves that are fueled by solid biofuels. Many people in developing countries also manage waste through open trash burning. The smoke exposure from these combustion activities is estimated to lead to approximately four million premature deaths each year. The emissions from these processes also add significantly to global emissions of greenhouse gases, short-lived climate forcing agents, and air pollutants.

In connection with greenhouse gases and the climate crisis, intensified wildfires across the globe increase human exposure to smoke-related air pollution. However, emission estimates from these various combustion processes (household burning and wildfires) and their atmospheric impacts are still highly uncertain. We use our pollutant sensing technology to estimate emissions and learn more about how to minimize exposure for people around the world.

Our Combustion Emissions Assessment Projects include:

  • Cookstove REACCTING Project: Stove technologies exist that enable reductions in the amount of fuel used for cooking, and in emissions. Yet, the extent to which these technologies will be utilized, change emissions, and impact health and atmospheric composition is unclear. The REACCTING project investigates the emissions changes resulting from a cookstove intervention in Ghana. More.
  • Heating and Indoor Air Quality on the Navajo Nation: This project is aimed at gaining a better understanding of how heating fuel choice can impact air quality in homes on the Navajo Nation.  Employing U-pod air quality monitors, developed by members of the Hannigan lab, in addition to filter sampling equipment, gas and particle-phase pollutants were measured inside and outside of homes in Tsaile, Arizona, and Shiprock, New Mexico. More.

  • Waste Burning Exposure Assessment: In Accra, Ghana, as well as other parts of the developing world, a common form of waste disposal is open burning. One-third of the airborne particulate matter (PM) emissions in Accra comes from the open burning of trash. The project’s objective aimed to analyze PM and carbon monoxide (CO) emissions from the burning of trash mimicking methods used in Accra. More.

VOC Sensors and Arrays for Hydrocarbon Quantification Projects

More recently our lab has begun exploring the use of low-cost VOC sensors for the quantification of methane and non-methane hydrocarbons. We are interested in using our sensors for applications ranging from long-term ambient methane monitoring to source apportionment of speciated VOCs. Hydrocarbon detection and monitoring present a unique challenge because typically many different hydrocarbons may originate from a single source and the types, as well as relative proportions of these different hydrocarbons, varies from source to source. For example, two different oil and gas basins may have very different makeups in terms of the relative proportions of methane, propane, ethane, etc… in the natural gas. For this reason, we calibrate specifically for the environment in which we plan to sample and we are exploring different types of analysis and the use of sensor arrays to better isolate particular hydrocarbons, such as methane, or improve our quantification of source compositions and contributions.

Our VOC sensors and Arrays for Hydrocarbon Quantification projects include: 

Other Air Quality Monitoring Research Projects

Air quality affects all aspects of our society, from how we build our indoor environments and generate renewable energy to how our communities and ecosystems grow and thrive. Our research expands into many of these aspects of life, described below.

Other Air Quality Monitoring Projects include: 

  • Air Quality and Solar Panel Soiling: Solar photovoltaic (PV) panels get dirty, or soiled, which decreases the PV energy yield. PV soiling leads to around $2 billion U.S. dollars lost annually worldwide [1]. In this research, we are exploring the ability to predict PV soiling performance using local air quality data. More.

  • Cherokee Concerned Citizens Fenceline Community Monitoring: Community concern over the health impacts of local industrial air pollution led to this project co-developed by CU Boulder’s Hannigan Air Quality (HAQ) Lab and CCC. Together we plan to amplify the community’s calls for environmental justice through air quality monitoring and data-informed storytelling. More.

  • Air Quality InQuiry Mongolian Chapter: Through a US State Department-sponsored Fellows On-Demand collaborative visit to Mongolia in October 2019, the Hannigan Research group partnered with Public Lab Mongolia, a non-governmental organization dedicated to environmental justice and open data, to expand the Air Quality InQuiry (AQIQ) program to Mongolian youth. More.