The U.S. Department of State and the U.S. Environmental Protection Agency work together to record air quality at U.S. Embassies and Consulates around the globe.

U.S. Consulate General Sao Paulo’s reference-grade Air Quality Monitor links Sao Paulo to the air quality index information and health messaging of the U.S. Environmental Protection Agency (EPA).  The air quality data collected is translated into actionable information by the EPA’s NowCast algorithm.  This algorithm converts raw PM 2.5 readings into an air quality index (AQI) value that can help inform health-related decisions.  The index is calculated based on data over a 3-to-12-hour period.  For more information about the EPA’s Air Quality Index, please visit https://www.airnow.gov/aqi/aqi-basics/using-air-quality-index/

U.S. Embassy and Consulate air quality monitors around the world measure airborne fine particulate matter.  Airborne fine particulate matter is commonly referred to as “PM 2.5” because it is less than or equal to 2.5 microns in diameter.  Pollutants such as particle pollution are linked to several significant health effects — and those effects are likely to be more severe for sensitive populations, including people with heart or lung disease, children, and older adults.  PM 2.5 is a standard recognized by the EPA.  For more information on the EPA’s Air Quality System, please visit https://www.epa.gov/aqs

Air quality index (AQI) values are typically grouped into ranges.  Each range is assigned a descriptor, a color code, and a standardized public health advisory.  Data from a single monitoring station cannot be applied to an entire city.  Therefore, air quality data collected at the U.S. Embassy and Consulates may differ from other monitors located in the same cities.

The AQI values can increase due to an increase of air emissions (for example, during rush hour traffic or when there is an upwind forest fire) or from a lack of dilution of air pollutants.  Stagnant air, often caused by an anticyclone, temperature inversion, or low wind speeds lets air pollution remain in a local area, leading to high concentrations of pollutants, chemical reactions between air contaminants and hazy conditions.