In early January 2025, wildfires swept through Los Angeles, causing extensive destruction and significantly impacting air quality across the region. Moreover, the outlook wasn’t good—between January 7 and January 12, bushfires burned across the state, consuming up to 80,000 homes and businesses. This devastation created an impending humanitarian crisis. As the smoke darkened our skies, the Environmental Protection Agency (EPA) watched with bated breath. They showed incredibly high concentrations of particulate matter in the air.
The EPA’s monitoring stations detected elevated levels of PM2.5, a harmful air pollutant, particularly in downtown Los Angeles and Compton. In downtown LA, PM2.5 levels skyrocketed into the “Unhealthy” category on the Air Quality Index (AQI). Compton experienced Unhealthy for Sensitive Groups AQI. The crisis deepened in locations nearer the fires, where a network of twelve low-cost sensors registered PM2.5 levels that fell within the “Hazardous” category.
Effects of Wildfires on Local Communities
The wildfires threaten to affect property with the greatest health impacts seen in homes within 25 kilometers of the fire’s perimeter. With homes and businesses numbering in the tens of thousands, many more people found themselves displaced and uncertain about what to do next. The fires fired up immediate urgency among local officials and leaders who were forced to react to the effects on public health and safety.
As the wildfires burned across the country, EPA’s monitoring stations were the primary source of information about the impact of hazardous air quality. Researchers used this rich dataset to determine how dramatically the fires polluted the air. Eight EPA stations from the AirNow network continuously monitored air quality throughout LA County. At the same time, a growing network of 728 low-cost particulate matter sensors gave us some important complementary context.
Claire Schollaert, lead author of the study recently published in Environmental Science & Technology Letters. She stressed the importance of real-time information during a crisis like this.
“Timely and accurate air quality information is crucial for the public to reduce their smoke exposure during wildfire events,” – Claire Schollaert
Schollaert’s research underscores the unmatched potential of pairing federal monitors, low-cost sensors, and satellite data. This method goes a long way in improving the public’s air quality awareness. Through this comprehensive approach, we hope to better equip residents with the knowledge to make informed decisions about their health when wildfires occur.
Monitoring Air Quality with Advanced Technology
In this study, researchers used innovative technology to measure air pollution levels. Retort tech has gotten cheaper and more accessible. They used satellite data to track smoke plume outlines and pollutant concentrations, providing a comprehensive picture of the crisis’ scale. Development of the AirNow Fire and Smoke Map, led by NOAA’s Hazard Mapping System. It was central to imagery development that helped visually depict smoke plumes descending on impacted communities.
Our analysis found that sensors within 4.7 miles (7.5 kilometers) of the wildfires detected hazardous PM2.5 levels. Each of these readings sparked national concern about the extraordinary public health risk posed by long-term exposure to polluted air in overburdened communities.
…bringing together various data streams to gain a better picture of what’s actually happening on the ground in terms of air quality, Schollaert said.
“Combining federal monitors, low-cost sensors, and satellite data can provide a more complete picture of local air quality, which can help people make safer choices in real time,” – Claire Schollaert
This all-hazards approach provides officials with the tools to respond swiftly and share life-saving information with citizens as incidents develop in real-time.
Looking Ahead: Addressing Air Quality Challenges
While Los Angeles continues to deal with the aftermath of the wildfires, improving air quality is an urgent need. The damaging disasters highlighted the dangers of the need for better monitoring systems and transparency to educate the public on short-term air pollution during natural disasters.
Health officials might point out that the long-term exposure to high PM2.5 levels has devastating impacts on respiratory health. This is particularly the case for vulnerable populations, both children and the elderly. As such, it is imperative for local governments and agencies to implement strategies aimed at improving air quality and safeguarding public health.
