Understanding Particulate Matter (PM)

The clean-exhaust system effectively reduces particulate matter in the air, but what exactly is particulate matter, and why is it important to address?

What Is Particulate Matter (PM)?

Particulate matter (PM) refers to tiny, often microscopic particles and droplets that can be suspended in the air. Many people are unaware of the existence of PM, let alone the implications of particle pollution. It's a common misconception that pollution is something distant, far above us in the sky. In reality, pollution is ever-present and pervasive, whether we're indoors or outdoors. With every breath we take, we inhale these microscopic particles, most of which are invisible to the naked eye. Despite their small size, PM is the type of air pollution that most significantly impacts our health.

The Origins of Particle Pollution

Particle pollution can be produced through mechanical and chemical processes. The mechanical process involves breaking down larger particles into smaller ones, without changing their chemical composition. Activities like agriculture, coal and oil combustion, dust storms, and construction generate many of these larger or coarse particles. On the other hand, the chemical process involves the vaporization and condensation of pollutants emitted from sources burning fuel, resulting in particles of the same chemical compound. These smaller particles can further react or combine with other compounds in the atmosphere. One of the major sources of particles created through this process is the burning of fossil fuels in various industries, transportation, and agriculture.

Diverse Shapes and Sizes of Particles

Particles come in various shapes and sizes, and they can be either solid particles or liquid droplets. The size of particles is directly linked to their potential health impacts. Environmental scientists typically categorize particles into two main groups: PM10 and PM2.5. PM10 includes particles between 2.5 and 10 microns in diameter (a human hair is about 60 microns in diameter), while PM2.5 encompasses particles smaller than 2.5 microns. These measurements usually refer to the total weight of the particles found. However, more advanced monitoring equipment counts and sizes individual particles, as seen in modern clean room monitoring devices such as the Dylos DC1100.

Different Characteristics of PM

PM10 and PM2.5 particles differ not only in size but also in material composition and sources of origin. Smaller particles can remain suspended in the air for longer periods before settling. PM2.5, being smaller and lighter, can stay in the air for hours to weeks and travel extended distances. In contrast, PM10 particles, being larger and heavier, remain in the air for minutes to hours and travel shorter distances.

Impact on Human Health

When you breathe, you inhale not only air but also any particles present in the air. These particles can adhere to the airway's walls or penetrate deeper into the lungs as you breathe. The body's defense mechanisms, including mucus and tiny hairs called cilia, help remove these particles from the lungs. However, PM2.5 particles can reach the deepest parts of the lungs where gas exchange occurs. These particles are particularly hazardous because the alveolar portion of the lungs has no efficient means of removing them. If the particles are water-soluble, they can enter the bloodstream within minutes, and if not, they remain in the lungs for an extended period.

Small particles that become trapped deep in the lungs can lead to lung diseases, emphysema, and, in some cases, lung cancer. Physical activity, which involves deeper and faster breathing, can lead to more particle inhalation. The United States Environmental Protection Agency (EPA) has reported that small particles can exit the lungs and travel through the bloodstream to other organs, including the heart.

Health Effects of PM Exposure

However, when the small particles go deeply into the lungs and become trapped this can result in lung disease, emphysema and/or lung cancer in some cases. Exercise and physical activity cause people to breather faster and more deeply and to take more particles into their lungs. The United States Environmental Protection Agency reported “studies suggested small particles can leave the lung and travel through the blood to other organs, including the heart”.

Health Effects of PM Exposure

Exposure to particulate matter can have several significant effects on health:

• Premature Mortality: Exposure to PM may result in premature deaths.
• Aggravation of Respiratory and Cardiovascular Diseases: Increased hospital admissions, emergency room visits, school absences, loss of workdays, and restricted activity days are indicators of aggravated asthma, acute respiratory symptoms, chronic bronchitis, decreased lung function, and increased myocardial infarction.
• At-Risk Populations: People with heart or lung diseases, including coronary artery disease, congestive heart failure, asthma, chronic obstructive pulmonary disease (COPD), and diabetes, are at higher risk due to particle aggravation. Infants, children, and older individuals are also vulnerable.

Addressing particulate matter is essential for mitigating these health impacts and improving overall air quality.