Recognized Carcinogens Released into Air
This indicator shows the total pounds of reported recognized carcinogens released into the air. This measure includes reported on-site and off-site carcinogens disposed of or otherwise released (in pounds), for all industries. Occupational Safety and Health Administration (OSHA) Carcinogens include reported amounts for each of the following four chemical categories: arsenic compounds; dioxin and dioxin-like compounds; chromium compounds; lead compounds; and polycyclic aromatic compounds (PACs). However, only part of each category is classified as an OSHA carcinogen (i.e., OSHA carcinogens include only inorganic arsenic compounds; chromium (VI) compounds; inorganic lead compounds; 2,3,7,8-tetrachlorodibenzo-p-dioxin; and all chemicals in the PACs category except for benzo(a)phenanthrene, dibenzo(a,e)fluoranthene, benzo(j,k)fluorene, and 3-methylcholanthrene).
Air Quality System
The Air Quality System (AQS), formerly the Aerometric Information Retrieval System (AIRS), is the Environmental Protection Agency's (EPA) repository of ambient air quality data. AQS stores data from over 10,000 monitors, 5,000 of which are currently active. The system contains ambient air pollution data collected by EPA, state, local, and tribal air pollution control agencies. AQS also contains meteorological data, descriptive information about each monitoring station (including its geographic location and its operator), and data quality assurance/quality control information. The Office of Air Quality Planning and Standards (OAQPS) and other AQS users rely upon the system data to assess air quality, assist in Attainment/Non-Attainment designations, evaluate State Implementation Plans for Non-Attainment Areas, perform modeling for permit review analysis, and other air quality management functions. AQS information is also used to prepare reports for Congress as mandated by the Clean Air Act.
http://www.epa.gov/ttn/airs/airsaqs
Methodology
EPA regulations require state environmental agencies to report air monitoring data at least quarterly. Data for one calendar quarter are due to EPA by the end of the following quarter.