Particulate matter and coal dust: Difference between revisions

From Voices in the Dust
Jump to navigation Jump to search
removed regulations text
 
(20 intermediate revisions by the same user not shown)
Line 1: Line 1:
=== '''Airborne Particles''' ===
== Airborne Particles ==
Airborne particles––also known as particulate matter (PM), particulates, or aerosols––refer to any mixture of solids and liquid droplets in the atmosphere. Particles can be directly emitted into the air or formed through chemical reactions of gaseous pollutants.  
Airborne particles––also known as particulate matter (PM), particulates, or aerosols––refer to any mixture of solids and liquid droplets in the atmosphere. Particles can be directly emitted into the air or formed through chemical reactions of gaseous pollutants.  


Particles are often distinguished by their size. The terms PM<sub>1</sub>, PM<sub>2.5</sub>, and PM<sub>10</sub> are common ways particles are described, measured, and regulated, with the number in the subscript indicating the diameter particles in micrometers. Particles can also be described as very-fine (PM<sub>1</sub>), fine (PM<sub>2.5</sub>), and coarse (PM<sub>10</sub>) particles, with PM<sub>10</sub> often called dust. Size affects how particles are regulated under the U.S. Clean Air Act and their health impacts.
Particles are often distinguished by their size. The terms PM<sub>1</sub>, PM<sub>2.5</sub>, and PM<sub>10</sub> are common ways particles are described, measured, and regulated, with the number in the subscript indicating the diameter of the particles in micrometers. Particles can also be discussed in terms of very-fine (PM<sub>1</sub>), fine (PM<sub>2.5</sub>), and coarse (PM<sub>10</sub>) particles, with PM<sub>10</sub> often referred to as dust. Size affects how particles are [[Regulation under the Clean Air Act|regulated under the U.S. Clean Air Act]] and their [[Health impacts: particles and coal dust|health impacts]].


=== '''Regulation under the Clean Air Act''' ===
== Coal Dust ==
Because they are harmful to our health, there are limits placed on airborne particles under the Clean Air Act. The U.S. Environmental Protection Agency (EPA) regulates PM<sub>2.5</sub> and PM<sub>10</sub> as two of six criteria pollutants that must meet specific concentration-based thresholds known as National Ambient Air Quality Standards (NAAQS), which you may hear pronounced as “the nacks”. The PM<sub>10</sub> NAAQS is a 24-hour average mass concentration of 150 μg/m<sup>3</sup>, not to be exceeded more than three times over three years. There are two PM<sub>2.5</sub> NAAQS: a 24-hour average mass concentration of 35 μg/m<sup>3</sup> and a recently revised annual average mass concentration of 9 μg/m<sup>3</sup>. The NAAQS are set to protect public health, including the health of more sensitive individuals such those with asthma as well as children and elders. That said, there is no known safe level of exposure to particles, with documented health impacts below the NAAQS. To determine NAAQS compliance, PM<sub>2.5</sub> and PM<sub>10</sub> must be measured using designated regulatory air monitors by an agency with the authority to do so, which in Virginia is the Virginia Department of Environmental Quality (VA DEQ).
Coal dust is a type of particulate matter that contains coal. Coal dust is produced through physical processes that wear on the brittle coal rocks during mining, transport, and storage to generate small coal particles that are then uplifted to the atmosphere and carried by winds. As a result, coal dust particles tend to be larger in size, including PM<sub>2.5</sub> and PM<sub>10</sub>, as well as even bigger PM that is visible with the unaided eye.<ref>Li, et al., [https://www.sciencedirect.com/science/article/abs/pii/S0032591016300341 Experimental Research of Particle Size and Size Dispersity on the Explosibility Characteristics of Coal Dust], ''Powder Technology'', 292, 290–297, 2016. </ref> Coal dust is lost from the atmosphere through deposition, leaving black dust films on outdoor and indoor surfaces. Coal dust contains toxic heavy metals that have serious [[Health impacts: particles and coal dust|health impacts]] at ambient concentrations below the [[U.S. Environmental Protection Agency (EPA)|U.S. Environmental Protection Agency]] [[Regulation under the Clean Air Act|National Ambient Air Quality Standards (NAAQS)]].


=== '''Documents''' ===
== Documents ==
 
* Coal Dust Residues on Homes in Southeast Newport News, 2024–2025 Photographs
<gallery mode="packed-hover" heights="400px">
File:Coal dust residue.jpg|Coal Dust Residues
File:Coal dust residue NN.jpg|Coal Dust Residues
File:Coal dust residue NN 2.jpg|Coal Dust Residues
</gallery>
 
== References ==

Latest revision as of 03:55, 5 June 2025

Airborne Particles

Airborne particles––also known as particulate matter (PM), particulates, or aerosols––refer to any mixture of solids and liquid droplets in the atmosphere. Particles can be directly emitted into the air or formed through chemical reactions of gaseous pollutants.

Particles are often distinguished by their size. The terms PM1, PM2.5, and PM10 are common ways particles are described, measured, and regulated, with the number in the subscript indicating the diameter of the particles in micrometers. Particles can also be discussed in terms of very-fine (PM1), fine (PM2.5), and coarse (PM10) particles, with PM10 often referred to as dust. Size affects how particles are regulated under the U.S. Clean Air Act and their health impacts.

Coal Dust

Coal dust is a type of particulate matter that contains coal. Coal dust is produced through physical processes that wear on the brittle coal rocks during mining, transport, and storage to generate small coal particles that are then uplifted to the atmosphere and carried by winds. As a result, coal dust particles tend to be larger in size, including PM2.5 and PM10, as well as even bigger PM that is visible with the unaided eye.[1] Coal dust is lost from the atmosphere through deposition, leaving black dust films on outdoor and indoor surfaces. Coal dust contains toxic heavy metals that have serious health impacts at ambient concentrations below the U.S. Environmental Protection Agency National Ambient Air Quality Standards (NAAQS).

Documents

  • Coal Dust Residues on Homes in Southeast Newport News, 2024–2025 Photographs

References