Microscopic Dust: A Dangerous Air Pollutant

Microdust, or fine dust, is a type of air pollution that is particularly harmful to human health. Fine dust particles are less than 2.5 micrometres in diameter, which means they can be inhaled and absorbed into the lungs and bloodstream. These particles are emitted from a variety of sources, including cars, trucks, power plants, and natural events such as wildfires. They can also be found in indoor air due to daily activities such as cooking, burning candles, and smoking. Fine dust has been linked to a range of health issues, including respiratory and heart problems, and can affect both adults and children. The issue of microdust has gained prominence in South Korea, with many residents expressing concerns about its impact on their daily lives and health.

Particulate matter (PM)

PM is classified based on the diameter of the particles. Coarse particles have a diameter greater than 2.5 μm, such as PM10, which is 10 μm in diameter. Fine particles, on the other hand, have diameters of 2.5 μm or less, often referred to as PM2.5. These fine particles pose the greatest risk to health as they can penetrate deep into the lungs and even enter the bloodstream. Long-term exposure to PM2.5 has been linked to premature death, especially in individuals with pre-existing heart or lung conditions. It also contributes to reduced lung function growth in children and adverse effects on ecosystems, including plants, soil, and water.

The sources of PM vary, and they can be either natural or anthropogenic. Natural sources include erosion of agricultural soils, volcanic eruptions, and sea-salt particles produced from bursting bubbles over the oceans. Anthropogenic sources, on the other hand, include traffic emissions, tyre and brake wear, coal combustion, and industrial activities such as factories and construction sites. Climate change is expected to influence PM concentrations in polluted environments, and wildfires fuelled by climate change could become a significant source of PM.

To protect public health, organizations like the US Environmental Protection Agency (EPA) have established regulations and standards for fine particle pollution (PM2.5). The EPA's rules aim to reduce emissions of pollutants that form PM, helping state and local governments meet national air quality standards. Additionally, tools like the Air Quality Index (AQI) provide daily information on air quality and associated health risks, enabling individuals and communities to take necessary precautions when PM levels are harmful.

The impact of particulate matter on human health and the environment is a global concern. While regulations and standards aim to mitigate the effects, public awareness and proactive measures are crucial in reducing the harmful impacts of PM exposure. Understanding the sources, size distribution, and chemical composition of particulate matter is essential for developing effective strategies to combat air pollution and safeguard public health.

Health effects

The health effects of micro dust air pollution, or particulate matter (PM), can vary depending on the size and chemical composition of the particles, as well as individual factors such as age and pre-existing health conditions.

PM10, or coarse particles, are those with a diameter of 10 microns or less, which can be inhaled into the lungs and induce adverse health effects. Sources of PM10 include dust from construction sites, landfills, agriculture, wildfires, industrial sources, wind-blown dust, pollen, and more. While these larger particles may primarily affect those with respiratory conditions such as asthma and emphysema, causing symptoms like eye and upper airway irritation, they can also have more serious health impacts. Studies have linked short-term exposure to PM10 to the worsening of respiratory diseases, including asthma and chronic obstructive pulmonary disease (COPD), sometimes requiring hospitalization.

PM2.5, or fine particles, are those with a diameter of 2.5 microns or less. Due to their smaller size, these particles can bypass the nose and throat and be absorbed by the lungs and bloodstream, leading to a range of health issues. Sources of PM2.5 include emissions from the combustion of gasoline, oil, diesel fuel, or wood, as well as industrial and transport sources. Exposure to PM2.5 has been linked to coughing, chest tightness, shortness of breath, eye/nose/throat irritation, and the triggering of asthma and other respiratory problems. Long-term exposure has been associated with an increased risk of heart attack, stroke, certain cancers, and birth defects, particularly in individuals with pre-existing heart or lung diseases, older adults, and children.

It is important to note that indoor air quality can also be affected by micro dust pollution, with activities such as cooking, burning candles or incense, and the use of certain cleaning products contributing to particulate matter. Additionally, outdoor pollution can enter indoor spaces through open windows, affecting indoor air quality.

Overall, the health effects of micro dust air pollution can be significant, particularly for vulnerable individuals, and it is important to take steps to minimize exposure and improve air quality, both indoors and outdoors.

Sources of micro dust

Particulate matter (PM) is a mixture of solid particles and liquid droplets found in the air. These particles vary in size, shape, and chemical composition. They may contain inorganic ions, metallic compounds, elemental carbon, organic compounds, and compounds from the earth’s crust.

PM10 refers to particles with a diameter of 10 microns or less, which are inhalable and can induce adverse health effects. PM10 sources include dust from construction sites, landfills, agriculture, wildfires, brush/waste burning, industrial sources, wind-blown dust from open lands, pollen, and fragments of bacteria.

PM2.5 refers to fine particles that are 2.5 microns or less in diameter. They pose the greatest risk to health as they can get deep into the lungs and even into the bloodstream. Sources of PM2.5 include emissions from the combustion of gasoline, oil, diesel fuel, or wood, as well as a significant proportion of PM10.

Some indoor sources of particulate matter include biological sources such as pollen, mold spores, dust mites, and cockroaches. Indoor activities such as smoking tobacco, cooking, and burning wood, candles, or incense can also generate particles. Particles can also form indoors from complex reactions of gaseous pollutants emitted from household cleaning products and air fresheners.

Other sources of particulate matter include metal-containing particles from frictional sources such as tyre and brake wear, mineral-containing particles from erosion of agricultural soils, volcanic eruptions, quarrying, and building activities, and cement and fertiliser dust from factories and construction sites. Sea-salt particles are also a source of particulate matter, produced from bursting bubbles over the oceans and at sea coasts.

How to reduce micro dust

While there is limited information on how to specifically reduce micro-dust, there is plenty of information on how to reduce dust and air pollution in general.

Micro-dust is a serious problem, especially in South Korea, where air pollution is a major issue. Doctors in respiratory clinics are kept very busy, and many people are considering migrating to escape the smog.

Dust particles play a role in many air pollution issues. Dust can cause respiratory and heart problems when small particles are inhaled. Particulate matter (PM) can be coarse, with a diameter greater than 2.5 μm (PM10), or fine, with a diameter less than 2.5 μm (PM2.5).

To reduce dust and air pollution, regular cleaning and vacuuming are essential. Here are some ways to reduce dust:

• Dust frequently with a duster or damp microfiber cloth to remove dust from shelves, blinds, and furniture tops.
• Vacuum regularly to capture dust securely without releasing it back into the air.
• Mop hard floors weekly with a microfiber mop and water or a gentle cleaner.
• Use an air purifier with a HEPA filter to remove particles from the air.
• If you have pets, groom them regularly to minimise shedding and reduce pet-related particles.
• Washable covers can be placed on furniture to protect surfaces from accumulating pet-related dust.
• Houseplants such as English ivy, peace lily, and snake plant can help to filter and absorb airborne particles, including dust.
• Use furniture polish or wax to create a protective barrier on furniture and surfaces.
• Avoid heating food in plastic containers, as this can release microplastics.
• Choose tap water over bottled water, as bottled water may contain microplastic particles.

Air quality standards and notifications

Air quality standards are the limit values set for specific air pollutants to protect public health and reduce air pollution. These standards are based on scientific evidence and expert evaluations to ensure that governments work towards improving the health of their citizens. While these guidelines are not legally binding, they offer critical guidance in mitigating the health impacts of air pollution.

The World Health Organization (WHO) plays a pivotal role in setting air quality guidelines and supporting countries in their quest for cleaner air. WHO's Air Quality Guidelines (AQG) are a set of evidence-based recommendations that provide target values for various air pollutants. These guidelines are dynamic, regularly updated, and designed to be adaptable to diverse conditions worldwide. They are informed by scientific evidence from multiple countries and rigorous evaluation methods, including systematic literature reviews and consultations with experts and end-users.

The WHO AQGs address a range of pollutants, including particulate matter (PM), nitrogen dioxide (NO2), sulfur dioxide (SO2), ozone (O3), and carbon monoxide (CO). Particulate matter, often referred to as dust particles, can be further classified into coarse particulates (PM10) with a diameter greater than 2.5 μm and fine particles (PM2.5) with a diameter less than 2.5 μm. These particles arise from various sources, including household fuel burning, industrial chimneys, traffic exhausts, and agricultural practices.

While the WHO provides global guidance, individual countries and regions may have their own unique air quality standards and regulations. For example, South Korea has been facing a serious problem with micro-dust air pollution, which has led to respiratory issues among its citizens and sparked discussions about migration to less polluted areas. The specific standards and notifications pertaining to air quality can vary based on a country's technical capabilities, economic capacity, air quality management policies, and other political and social factors.

It is important to recognize that air quality standards are subject to ongoing revisions as new scientific evidence emerges. Governments and organizations strive to balance economic development with the imperative to safeguard public health and the environment. By adopting and implementing these standards, societies can work towards mitigating the detrimental effects of air pollution and fostering a healthier future for their citizens.

Frequently asked questions