This US EPA feature layer is updated hourly and reflects the latest hour of air quality data received from each monitoring site that reports to AirNow. The concentration and AQI values are for Ozone and Particulate Matter (PM) only. Air quality index ranges from 0-5,000 with higher values indicating worse air quality.
EPA RSEI Score, 2021
This layer displays RSEI score by county. A RSEI Score is a unitless value that accounts for the size of the chemical release, the fate and transport of the chemical through the environment, the size and location of the exposed population, and the chemical’s toxicity. RSEI scores are designed to be compared to each other. A RSEI Score 10 times higher than another RSEI Score suggests that the potential for risk is 10 times higher. Relatively small releases may lead to high RSEI Scores if the toxicity weight is particularly high or if the estimated exposed population is large. Conversely, large releases may lead to low RSEI Scores if the toxicity weight is low or if the estimated exposed population is small. A low RSEI Score indicates low potential concern from reported TRI releases, but other kinds of environmental risk may also be present, including pollution from mobile sources like cars and trucks, hazardous waste, and unreported releases from facilities.
Gross Pollutant Releases
This layer displays the total pounds of toxic pollutants released by industrial and federal facilities.
Air Toxics – Cancer Risk by Census Tract
Layer displays the modeled cancer risk associated with air toxics exposure. Figures represents the likelihood of hazardous exposure per 1 million population.
Air Toxics – Non-Cancer Risk by Census Tract
Layer displays the modeled non-cancer risk associated with air toxics exposure. A hazard index (HI) of 1 or lower means air toxics are unlikely to cause adverse noncancer health effects over a lifetime of exposure.
Air Quality – Ozone Levels (O3) by Census Tract, 2019
This layer displays the daily average concentration of ozone and the percentage of days with concentrations of ozone above the National Ambient Air Quality Standard (NAAQS) of 0.075 parts per million in 2019.
Air Quality – Fine Particulate Matter (PM2.5) by Census Tract, 2018
This layer displays the daily average concentration of fine particulate matter and the percentage of days with concentrations of fine particulate matter above the National Ambient Air Quality Standard (NAAQS) of 35.0 micrograms per cubic meter in 2018.
Air Quality – Fine Particulate Matter (PM2.5) by Census Tract, 2019
This layer displays the daily average concentration of fine particulate matter and the percentage of days with concentrations of fine particulate matter above the National Ambient Air Quality Standard (NAAQS) of 35.0 micrograms per cubic meter in 2019.
Air Quality – Daily Concentration, Particulate Matter (PM 2.5) by County, 2017
This layer displays the daily average concentration of fine particulate matter and the percentage of days with concentrations of fine particulate matter above the National Ambient Air Quality Standard (NAAQS) of 35.0 micrograms per cubic meter in 2017.
Air Quality – Daily Concentration, Particulate Matter (PM 2.5) by County, 2017
This layer displays the daily average concentration of fine particulate matter and the percentage of days with concentrations of fine particulate matter above the National Ambient Air Quality Standard (NAAQS) of 35.0 micrograms per cubic meter in 2018.