Air Monitoring Q&A
Learn more about the IVAN Air Monitoring network and how to read the air quality data.
About the air monitoring
1. What is IVAN Air Monitoring?
IVAN Air Monitoring shows current air quality from a network of community air sensors operated in partnership with Comité Cívico del Valle. Each monitor measures fine particle pollution (PM2.5), and this website shows the resulting US EPA Air Quality Index (AQI) at each location.
The goal is to give neighbors a fast, local picture of air quality so they can take action to protect their health.
2. How is this different from government air monitors?
These are low-cost community sensors (PurpleAir) placed at the neighborhood level. They are not regulatory monitors and cannot be used to determine whether air quality laws are being met. Government regulatory monitors are the official source for that.
Community monitors are useful because they show air quality at many more locations and update frequently. Use both sources together, and when in doubt follow the most health-protective reading.
3. Why is a monitor gray or offline?
A gray monitor isn't reporting data right now. This can happen if the sensor lost its internet connection or needs maintenance. It usually comes back online on its own or after a quick check.
About the data
1. What air quality data does the website show?
For each community monitor we show the US EPA AQI based on the 1-hour average PM2.5. Open a monitor to also see its 6-hour, 24-hour and 1-week PM2.5 averages, plus temperature and humidity. View the monitors.
2. Are these data validated?
The readings come straight from the sensors and are preliminary — they are not independently verified or validated. They should be used for community awareness and with discretion, not to infer violations of the law.
3. How often is it updated?
Air quality readings are refreshed regularly (about once per hour). We use the 1-hour average so a brief, momentary spike doesn't over-report the air quality.
Understanding the US EPA AQI
1. What is the AQI?
The US EPA Air Quality Index (AQI) is a standard scale that turns the amount of particle pollution into a number and a color, showing how healthy or unhealthy the air is. A higher number means more pollution and greater risk to your health.
*Sensitive groups include children, teens, older adults, pregnant people, and people with heart, lung, or other chronic conditions.
2. How is the AQI calculated?
The PM2.5 concentration measured by the sensor (in µg/m³) is converted to an AQI value using the U.S. EPA's standard breakpoints. On this website we apply that calculation to the 1-hour average PM2.5 reading from each monitor.
Air quality and health
1. What is particulate matter (PM2.5)?
Particulate matter is a mix of tiny solid and liquid particles in the air. PM2.5 are particles 2.5 micrometers or smaller — small enough to be inhaled deep into the lungs, which is why they are a health concern. Common sources include vehicle traffic, dust, smoke, agriculture, and wildfires.
2. Who is most affected by particle pollution?
Sensitive groups — children, older adults, pregnant people, and anyone with a heart or lung condition such as asthma — are most at risk, especially during short-term spikes. At higher levels, particle pollution can affect everyone.
3. How can I reduce my exposure?
Be aware of the air quality near you and take action when levels are unhealthy — spend less time outdoors and lower your activity (for example, walk instead of run).
Sign up for air quality alerts to get an email when a community monitor near you reaches the level you choose.
Report an air problem
1. What should I do if I notice an air quality problem?
If you are experiencing an emergency, call 9-1-1.
For an air quality complaint, contact your local Air Pollution Control District as soon as you notice the problem. We also recommend you submit a report here on IVAN so the issue is documented and the Environmental Justice Task Force is aware of it.