What Is Ambient Air?

Air quality is an important issue, especially in highly regulated industries such as coal mining, cement processing, and coal‐ and oil‐fired power generation. Rules such the Mercury and Air Toxics Standards (MATS) and the Maximum Achievable Control Technology (MACT) Standards are designed to protect the public and keep ambient air pollution-free. Ozone is another pollutant of ambient air that has been linked to global warming and health risks for children. The Clean Air Act requires EPA to set National Ambient Air Quality Standards (NAAQS) for six principal pollutants, called “criteria pollutants,” that are common in outdoor air, considered harmful to public health and the environment, and that come from numerous and diverse sources. According to the EPA website, primary standards are meant to protect public health with an adequate margin of safety; whereas, secondary standards are designed to protect the public welfare from adverse effects on soil, water, crops, vegetation, animals, weather, visibility, climate, and others. There are many guidelines for coal, mining, and cement facilities, but this article will discuss ambient air in general.

What do we mean by ambient air?

When we searched for the meaning of ambient air, we got an AI generated answer that refers to the natural, unpolluted atmospheric air, typically consisting of nitrogen and oxygen, along with trace gases. It’s the outside air we breathe, distinct from air within buildings or confined spaces. Ambient air quality is monitored to ensure it meets specific standards for human health and environmental protection. Ambient air is primarily composed of 78% nitrogen and 21% oxygen. It’s considered natural and uncontaminated, meaning it’s not significantly affected by industrial emissions, vehicle exhaust, or other pollutants.

What is ambient air pollution?

The World Health Organization (WHO) defines ambient air pollution as potentially harmful pollutants emitted by industries, households, cars, and trucks. Of all of these pollutants, fine particulate matter has the greatest effect on human health. Most fine particulate matter comes from fuel combustion from vehicles, power plants, industry, households, or biomass burning. WHO reported that in 2019, 99% of the world’s population was living in places where the WHO air quality guidelines levels were not met, and that the combined effects of ambient air pollution and household air pollution are associated with 6.7 million premature deaths annually. It went on to report that ambient (outdoor) air pollution is estimated to have caused 4.2 million premature deaths worldwide in 2019.

Ambient air monitoring technologies

Advanced technology is available to monitor particulates in ambient air. These instruments measure critical regulatory parameters including PM-10 and PM-2.5 mass concentration as it exists in ambient air. Monitoring for aerosols and dust within a designated area, whether for research or routine input, can include various industry-proven particulate matter technologies, such as Beta attenuation and SHARP particulate monitors, Partisol air samplers, and TEOM continuous particulate monitors.

The principle behind beta attenuation particulate sampling instruments (beta gauge) is that energy is absorbed from beta particles as they pass through particulate matter (PM) collected on a filter media. Some beta gauge instruments have been designed to take advantage of this scientific principle to accurately monitor and measure PM concentrations. Partisol monitors measure particles in air by drawing air through a pre-weighed filter at a known flow rate for specified amounts of time, allowing for unattended daily sampling of particulate matter. Tapered element oscillating microbalances technology (TEOM) are gravimetric solutions that draw conditioned ambient air through a filter at a constant flow rate, continuously weighing the filter and calculating near real-time mass concentrations of particulate matter.

Portable and personal instruments are also available to monitor ambient air in the workplace to help detect the presence of toxic vapors and gases.

Why monitor the air?

Without such technology and equipment, respirable particles can settle deep in the lungs, resulting in serious health and respiratory problems, such as decreased lung function, asthma, irregular heartbeat, Black Lung Disease and chronic bronchitis.

According to the U.S. EPA, there are many reasons why ambient air monitoring is needed:

assess the extent of pollution;
provide air pollution data to the general public in a timely manner;
support implementation of air quality goals or standards;
evaluate the effectiveness of emissions control strategies;
provide information on air quality trends;
provide data for the evaluation of air quality models; and
support research (e.g., long-term studies of the health effects of air pollution).

Additional Resources

Editor’s Note: This article was originally published on this blog 8/8/17, but has been refreshed with updated information and broken links have been fixed.