Pollutant and Greenhouse gas An air pollutant is a material in the air that can have adverse effects on humans and the ecosystem. The substance can be solid particles, liquid droplets, or gases. A pollutant can be of natural origin or man-made. Pollutants are classified as primary or secondary.
AQI values of or greater are calculated with hour SO2 concentrations. Real time monitoring data from continuous monitors are typically available as 1-hour averages. However, computation of the AQI for some pollutants requires averaging over multiple hours of data.
For example, calculation of the ozone AQI requires computation of an 8-hour average and computation of the PM2. To accurately reflect the current air quality, the multi-hour average used for the AQI computation should be centered on the current time, but as concentrations of future hours are unknown and are difficult to estimate accurately, EPA uses surrogate concentrations to estimate these multi-hour averages.
For reporting the PM2. The Nowcast is a particular type of weighted average that provides more weight to the most recent air quality data when air pollution levels are changing.
The impetus was to draw public attention to the issue of air pollution and indirectly push responsible local public officials to take action to control sources of pollution and enhance air quality within their jurisdictions.
Jack Fensterstock, the head of the National Inventory of Air Pollution Emissions and Control Branch, was tasked to lead the development of the methodology and to compile the air quality and emissions data necessary to test and calibrate resultant indices.
These indices were then weighted and summed to form a single total air quality index. The overall methodology could use concentrations that are taken from ambient monitoring data or are predicted by means of a diffusion model.
The concentrations were then converted into a standard statistical distribution with a preset mean and standard deviation. The resultant individual pollutant indices are assumed to be equally weighted, although values other than unity can be used.
Likewise, the index can incorporate any number of pollutants although it was only used to combine SOx, CO, and TSP because of a lack of available data for other pollutants.
While the methodology was designed to be robust, the practical application for all metropolitan areas proved to be inconsistent due to the paucity of ambient air quality monitoring data, lack of agreement on weighting factors, and non-uniformity of air quality standards across geographical and political boundaries.
Despite these issues, the publication of lists ranking metropolitan areas achieved the public policy objectives and led to the future development of improved indices and their routine application.National Digital Air Quality Forecast Guidance Page.
The starting point for graphical digital government air quality guidance. Display current and forecast air quality conditions across the U.S.
Drill down to explore data at individual monitors.
Fires Fires Explore current locations of wildfires, smoke plumes, and air quality monitors. Includes advisories and health information about wildfires. initiativeblog.com - Home of the Air Quality Index. The Air Management Data Viewer is an interactive map that displays information such as permitted facilities and their emissions, air quality monitoring sites and nonattainment areas in Wisconsin.
Aug 14, · The Air Quality Index is a daily index of air quality that reports how clean the air is and provides information on potential health risks. Oregon’s index is based on three pollutants regulated by the federal Clean Air Act: ground-level ozone, particle pollution and nitrogen dioxide.
National Digital Air Quality Forecast Guidance Page.
The starting point for graphical digital government air quality guidance. Oct 11, · Air pollution is a mixture of natural and man-made substances in the air we breathe.
It is typically separated into two categories: outdoor air pollution and indoor air pollution. In some instances, outdoor air pollution can make its way indoors by way of open windows, doors, ventilation, etc. What.