Air Monitoring
Ambient Monitoring Program

Monitoring Site


Monitoring Data
- Current Data (By Site)
- Current Data (By Monitor)

Map of Current Air Monitors

Latest Air Quality Index Readings

Annual Network Plan

Pollen Monitoring
- Current Pollen Report
- Pollen Trend Report

Quality Assurance Documents

Special Studies & Exceptional Events

Data Archives and Statistical Summaries

Haze Cameras

Current NAAQS


Hazardous Air Pollutant Reports


Donnie Redmond
Ambient Monitoring Section Chief
Phone 919-707-8468
Fax 919-715-8468

Joette Steger, Ph.D.
Projects and Procedures Branch Supervisor
Phone 919-707-8449
Fax 919-715-8449

Jim Bowyer, Ph.D.
Laboratory Analysis Branch Supervisor
Phone 919-715-7484
Fax 919-733-0890

Justin Davis
Electronics and Calibrations Branch Supervisor
Phone 919-715-1761
Fax 919-733-6578

Current Data by Site Current Data by Monitor Latest Air Quality Index

"Ambient air" is the outside air that we all breathe. This term is specifically defined by EPA as "that portion of the atmosphere, external to buildings, to which the general public has access."

In the early 1970s, the EPA listed six major air pollutants that affected the quality of ambient air and established concentration limits for these pollutants. These limits are known as the National Ambient Air Quality Standards (NAAQS). Primary limits or standards were established to protect human health and secondary standards were established to protect human welfare and the quality of life. Through the years, the NAAQS have been revised and amended to account for evolving scientific understanding of air pollution and its impacts. Currently, the six criteria pollutants are:

  • Ozone (O3)
  • Particulate Matter (PM 2.5 and PM 10)
  • Carbon Monoxide (CO)
  • Sulfur Dioxide (SO2)
  • Nitrogen Dioxide (NO2)
  • Lead (Pb)

These six pollutants can cause serious human health problems (including premature mortality) and damage the environment and property. Common sources of these pollutants are coal-fired power plants, industrial manufacturing sources, and on-road and off-road vehicles. These standards can be viewed on-line at the National Ambient Air Quality Standards (NAAQS) page.

The Clean Air Act (CAA) requires the states to set up air monitoring networks to measure these six pollutants. The methods used to sample these pollutants are referred to as either "reference" or "equivalent" methods and must be approved by EPA before being used. The required methods for sampling these six pollutants and ambient limits themselves are codified in the Code of Federal Regulations at 40 CFR Part 50.

Background information about the annual Air Monitoring Network Design Plan and a general overview of how the state's air monitoring networks are operated can be found here.

The Ambient Monitoring Section is responsible for measuring levels of regulated pollutants in the ambient air. It is divided into three different branches:

Projects and Procedures Branch
The Projects and Procedures Branch is responsible for maintaining the overall quality control for all ambient monitors operated by the State and local programs. Electronically polled data is checked daily by the headquarters and several times a week by the regional offices for quality control purposes. These instruments must follow EPA-approved Quality Assurance/Standard Operating Procedures that are updated and reviewed on a regular basis by this branch.

Laboratory Analysis Branch (LAB)
is responsible for conducting the laboratory-based analyses of samples collected at air monitoring sites across the state. The LAB is responsible for collection and analysis of samples for fine particulate matter (PM2.5 and PM10), pollen, volatile organic compounds, aldehydes, and ozone precursor hydrocarbon compounds. The LAB also oversees the collection and analysis of rain water samples for mercury deposition at two site through the National Atmospheric Deposition Network's Mercury Deposition Network (MDN). In addition to these efforts, the LAB provides laboratory capabilities for special investigative studies. These analyses are conducted at two laboratory facilities in Raleigh, NC.

Electronics and Calibrations Branch
The Electronics and Calibration Branch provides technical support to the Division of Air Quality and the Ambient Monitoring Section. This is accomplished by performing installations, repairs, maintenance, calibrations, certifications, audits and training on the air monitoring equipment.