AirNow

AirNow
Name	AirNow
Type	Public information service
Founded	2000
Owner	United States Environmental Protection Agency
Area served	United States

AirNow AirNow is a United States federal air quality information service that provides localized air pollution data and forecasts. It aggregates observations from networks such as the Environmental Protection Agency and state agencies, distributes the Air Quality Index and issues health guidance to agencies like the Centers for Disease Control and Prevention and emergency managers. AirNow interoperates with meteorological models and public alert systems used by the National Weather Service, Federal Emergency Management Agency, and health departments.

Overview

AirNow consolidates observational streams from federal and state sources including the Environmental Protection Agency, National Oceanic and Atmospheric Administration, State of California Air Resources Board, Texas Commission on Environmental Quality, and regional air districts such as the South Coast Air Quality Management District. The platform publishes current conditions, forecasts, and historical records used by Centers for Disease Control and Prevention, Occupational Safety and Health Administration, Department of Homeland Security, American Lung Association, and municipal agencies in cities like Los Angeles, Chicago, New York City, Denver, and Seattle. It supports data exchange standards embraced by organizations including the Open Geospatial Consortium and the World Health Organization air quality initiatives.

History

AirNow originated from interagency efforts in the late 1990s to standardize dissemination of the Air Quality Index across the United States, coordinated by the Environmental Protection Agency with partners such as the National Oceanic and Atmospheric Administration and the Department of Health and Human Services. Early deployments tied into regional monitoring programs like the State and Local Air Monitoring Stations network and initiatives following events such as the 2001 California wildfires and the 2003 Eastern United States blackout, which highlighted the need for centralized exposure information used later in responses to incidents including the 2012 Hurricane Sandy and the 2020 Western United States wildfire season.

Data and Technology

AirNow ingests sensor readings from continuous monitors operated by the Environmental Protection Agency, state agencies, tribal programs like the Navajo Nation Environmental Protection Agency, and academic networks at institutions such as the University of California, Berkeley, Colorado State University, and Johns Hopkins University. It integrates remote sensing inputs from satellite missions like MODIS, VIIRS, and programs at NASA and assimilates model output from the National Air Quality Forecasting Capability, driven by the Global Forecast System and chemical transport models used by the European Centre for Medium-Range Weather Forecasts. The technical stack uses standards from the Open Geospatial Consortium, data schemas compatible with the AirNow-Exchange, and visualization tools similar to those employed by the National Weather Service and the National Oceanic and Atmospheric Administration’s data portals.

Air Quality Index and Public Health Guidance

AirNow operationalizes the Air Quality Index adopted by the Environmental Protection Agency and referenced by the World Health Organization in guidance documents. AQI categories—such as Good, Moderate, Unhealthy for Sensitive Groups, Unhealthy, Very Unhealthy, and Hazardous—align with concentration breakpoints for pollutants regulated under the Clean Air Act including particulate matter, ground-level ozone, carbon monoxide, sulfur dioxide, and nitrogen dioxide. Public health advisories produced for agencies like the Centers for Disease Control and Prevention, American Medical Association, and local health departments inform protective actions for populations in Los Angeles County, Cook County, King County, and tribal lands.

Partnerships and Governance

Governance of AirNow involves interagency collaboration among the Environmental Protection Agency, National Oceanic and Atmospheric Administration, Department of Homeland Security, Centers for Disease Control and Prevention, and state and tribal environmental agencies. Partnerships extend to non-governmental organizations such as the American Lung Association, AirNow International cooperative programs, academic partners at Massachusetts Institute of Technology and University of Washington, and industry stakeholders including sensor manufacturers certified under programs like those run by the South Coast Air Quality Management District. Oversight aligns with statutory frameworks like the Clean Air Act and reporting obligations to entities such as the United States Congress and the Government Accountability Office.

Impact and Usage

AirNow data support public communications by media outlets including The New York Times, Los Angeles Times, and broadcast partners of the National Weather Service. Emergency response agencies including the Federal Emergency Management Agency and municipal offices in San Francisco, Phoenix, Houston, and Boston use AirNow for routing and shelter decisions during events like wildfires and industrial accidents. Researchers at institutions such as Harvard T.H. Chan School of Public Health, University of California, Los Angeles, and Columbia University use AirNow datasets in epidemiological studies on cardiovascular and respiratory outcomes, informing policy deliberations in bodies like the Environmental Protection Agency’s advisory committees and the United States Senate hearings.

Criticisms and Limitations

Critics including some academic groups at Stanford University, University of Michigan, and advocates like the Environmental Defense Fund point to spatial coverage gaps where regulatory monitors are sparse, leading users to rely on low-cost sensors from vendors or community networks coordinated by organizations like the South Coast Air Quality Management District or citizen science projects at Public Lab. Limitations in representing indoor exposures, latency of regulatory-grade monitoring, and differences between model forecasts and observed concentrations have been noted in evaluations by the Government Accountability Office and peer-reviewed studies published in journals such as Environmental Health Perspectives and Atmospheric Environment. Questions about communication equity have been raised by public health researchers at Johns Hopkins University and community groups in regions including the San Joaquin Valley.

Category:Air pollution