Air Pollution's Pm: What, Why, And How?

Particulate Matter (PM) is a term for a mixture of solid particles and liquid droplets found in the air. PM pollution, or particle pollution, is a complex mixture of solids and aerosols composed of small droplets of liquid, dry solid fragments, and solid cores with liquid coatings. PM pollution can be emitted directly from sources such as construction sites, unpaved roads, and smokestacks, or formed in the atmosphere through chemical reactions of gases (secondary particles) such as sulfur dioxide and nitrogen oxides. PM2.5 and PM10 are common terms used to describe the size of particulate matter, with PM2.5 being fine inhalable particles with diameters of 2.5 micrometers or less, and PM10 being inhalable coarse particles with diameters between 2.5 and 10 micrometers. These particles can have adverse health effects, with PM2.5 being associated with a higher proportion of negative health impacts compared to PM10.

PM2.5 and PM10: fine and coarse particles

PM stands for particulate matter, also known as particle pollution. It refers to a mixture of solid particles and liquid droplets found in the air. Some particles, such as dust, dirt, soot, or smoke, are large enough to be visible, while others are so small that they can only be seen through an electron microscope.

PM2.5 and PM10 are types of fine and coarse particles, respectively, that are classified based on their size. PM2.5 particles have diameters of 2.5 micrometers or smaller, while PM10 particles have diameters of 10 micrometers or smaller. To put this into perspective, an average human hair is about 70 micrometers in diameter, making it 30 times larger than the largest PM2.5 particle.

These particles come in various sizes and shapes and can be composed of hundreds of different chemicals. They can be emitted directly from sources such as construction sites, unpaved roads, fields, smokestacks, or fires. However, most particles form in the atmosphere through complex reactions of pollutants like sulfur dioxide and nitrogen oxides, which are released from power plants, industries, and automobiles.

PM2.5 and PM10 have different sources and chemical compositions. PM2.5 particles are primarily generated from the combustion of gasoline, oil, diesel fuel, or wood. They are also found indoors due to activities like smoking tobacco, cooking, burning candles or incense, and using household cleaning products. On the other hand, PM10 particles include dust from construction, landfills, agriculture, wildfires, industrial sources, wind-blown dust, pollen, and bacterial fragments.

Both PM2.5 and PM10 can be inhaled and have adverse effects on human health. Due to their smaller size, PM2.5 particles can penetrate deeper into the lungs and have been linked to various health issues, including premature mortality, increased hospital admissions for heart or lung problems, bronchitis, asthma attacks, and respiratory symptoms. PM10 particles, on the other hand, tend to deposit in the upper region of the lung and have been associated with respiratory mortality. Long-term exposure to these particles, especially in vulnerable groups such as children, older adults, and people with pre-existing heart or lung conditions, can result in serious health consequences.

Health effects: respiratory issues, heart disease, and more

PM stands for particulate matter, a term for a mixture of solid particles and liquid droplets found in the air. Some particles, such as dust, dirt, soot, or smoke, are large or dark enough to be seen with the naked eye. Others are so small they can only be detected using an electron microscope. These particles come in many sizes and shapes and can be made up of hundreds of different chemicals.

PM2.5 refers to fine inhalable particles with diameters generally 2.5 micrometres and smaller. To put this into context, the average human hair is about 70 micrometres in diameter, making it 30 times larger than the largest fine particle. PM2.5 is produced by the combustion of gasoline, oil, diesel fuel, or wood. It is also a component of smoke from wildland fires, including wildfires and prescribed fires.

PM air pollution can have significant respiratory effects. Short-term exposure to PM2.5 has been linked to premature mortality, increased hospital admissions for respiratory issues, acute and chronic bronchitis, asthma attacks, emergency room visits, respiratory symptoms, and restricted activity days. These adverse effects are primarily seen in infants, children, and older adults with pre-existing respiratory diseases. Long-term exposure to PM2.5 has been associated with reduced lung function growth in children and an increased risk of early death from respiratory causes.

Additionally, PM air pollution can impact cardiovascular health. Short-term exposure can increase the risk of heart attack, stroke, arrhythmias, and heart failure in susceptible individuals, such as the elderly or those with pre-existing cardiovascular conditions. Long-term exposure to PM2.5 has been linked to an elevated risk of mortality from cardiovascular causes, including heart disease, stroke, and atherosclerosis. Research suggests that air pollution contributes to the development and progression of atherosclerosis, which involves plaque buildup in the artery walls, leading to heart disease.

Outdoor sources: vehicle exhaust, burning wood, etc

Outdoor sources of particulate matter (PM) air pollution include vehicle exhaust and burning wood, among other things. PM refers to a mixture of solid particles and liquid droplets found in the air. These particles vary in size, shape, and chemical composition and may contain inorganic ions, metallic compounds, elemental carbon, organic compounds, and compounds from the Earth's crust.

Vehicle Exhaust

Motor vehicle exhaust is a significant source of outdoor air pollution. Studies have found elevated levels of pollutants, including ultrafine particulates (UFP), black carbon (BC), oxides of nitrogen (NOx), nitrogen dioxide (NO2), carbon monoxide (CO), volatile organic compounds (VOCs), and particle-bound polycyclic aromatic hydrocarbons (PPAH), in the air near highways, major roads, and busy urban streets. The health risks associated with exposure to these pollutants include an increased risk of developing asthma, reduced lung function, and pulmonary and cardiac mortality, especially in children and individuals with pre-existing heart or lung diseases.

Burning Wood

Residential wood burning is a major source of PM2.5 emissions, especially in densely populated neighbourhoods and during winter. In the European Union, wood burning accounts for 51% of total PM2.5 emissions, and in certain regions, such as Île-de-France, it contributes to 56% of wintertime PM1 emissions. Wood smoke contains fine particles that can infiltrate the respiratory system and cause various health issues, including eye and respiratory irritation, bronchitis, asthma attacks, and potentially more severe conditions like heart attacks, strokes, and heart failure.

Other Outdoor Sources

Other outdoor sources of PM pollution include combustion processes involving gasoline, oil, and diesel fuel, as well as dust from construction sites, landfills, agriculture, wildfires, industrial sources, wind-blown dust, pollen, and bacterial fragments.

Indoor sources: tobacco smoke, frying food, fireplaces, etc

PM stands for particulate matter, also known as particle pollution. It refers to a mixture of solid particles and liquid droplets found in the air. These particles vary widely in size, shape, and chemical composition. They include inorganic ions, metallic compounds, elemental carbon, organic compounds, and compounds from the earth's crust.

Indoor sources of PM pollution include tobacco smoke, frying food, fireplaces, and other combustion activities. Tobacco smoke, including secondhand smoke, is a significant source of indoor PM2.5 pollution. It contains numerous pollutants and is closely correlated with chronic lung diseases. Frying food and other cooking activities, such as grilling, baking, or sautéing, can also produce high levels of PM, especially when food is burned. The type of food, cooking method, and cooking fat used all impact the amount of PM generated during cooking.

Fireplaces and fuel-burning appliances, such as stoves, heaters, and furnaces, are another source of indoor PM pollution. When using these appliances, it is essential to ensure proper ventilation and follow best practices, such as using dry, seasoned wood and providing sufficient air to the fire to prevent smoldering.

Other indoor activities, such as burning candles, incense, or oil lamps, and even everyday activities like cleaning and vacuuming, can also contribute to indoor PM levels. Settled indoor dust, which can be easily disturbed and inhaled, is often composed of PM from various sources. Therefore, it is crucial to maintain good indoor air quality by implementing proper ventilation, following recommended practices, and taking breaks when engaging in activities that may generate high levels of PM.

Air quality alerts and forecasts

PM stands for particulate matter, or particle pollution, which is a mixture of solid particles and liquid droplets found in the air. These particles vary in size, shape, and chemical composition and can be emitted directly from sources such as construction sites, unpaved roads, and smokestacks, or formed in the atmosphere through chemical reactions.

The NowCast AQI displays the highest AQI among pollutants such as ozone, PM2.5, and PM10 for each monitor and contour every hour. PM2.5 refers to fine inhalable particles with diameters of 2.5 micrometres or less, while PM10 includes particles with diameters of up to 10 micrometres. These particles can have adverse health effects, with PM2.5 being associated with the greatest proportion of adverse health impacts related to air pollution. Short-term exposure to PM2.5 has been linked to increased hospital admissions for heart and lung issues, asthma attacks, and respiratory symptoms, especially in infants, children, and older adults with pre-existing conditions. Long-term exposure can lead to premature death and reduced lung function growth in children.

To stay informed about air quality and potential health risks, individuals can utilise resources such as the AirNow website and interactive map, which provide regularly updated data and forecasts. By understanding the AQI and taking appropriate actions, communities can adjust outdoor activities and protect the health and well-being of their citizens, particularly vulnerable groups, during periods of poor air quality.

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