Dust: What's In The Air We Breathe?

Dust is made up of a variety of substances, both inside and outside the home. Dust in homes is composed of about 20–50% dead skin cells, with the rest made up of small amounts of plant pollen, human hairs, animal fur, textile fibers, paper fibers, minerals from outdoor soil, burnt meteorite particles, and many other materials which may be found in the local environment. Dust mites, which are microscopic arachnids that feed on dead skin cells, are also a major component of house dust. Dust can also contain harmful chemicals, such as phthalates, PFAS, and bisphenols, which can have negative impacts on human health. Outdoor dust, on the other hand, is primarily composed of particles in the atmosphere, such as soil lifted by the wind, volcanic eruptions, and pollution. Road dust, for example, consists of deposits of vehicle and industrial exhaust gas, particles from tire and brake wear, and dust from construction sites. Understanding the composition of dust is important for maintaining indoor air quality and reducing potential health risks associated with exposure to certain pollutants.

Dust mites

To reduce dust mites in the home, it is important to control humidity levels. Dust mites absorb moisture from the air, so they cannot survive in low-humidity areas. Maintaining humidity levels below 50% can help reduce dust mites. Using a dehumidifier or air conditioner can assist in achieving this.

Additionally, it is recommended to use furniture with smooth surfaces that are easy to clean and do not trap dust easily. Leather couches, for example, are less likely to accumulate dust than upholstered couches. Removing drapes and curtains and covering mattresses and pillows with allergen-impermeable covers can also help reduce dust mites. Regularly washing bedding and blankets in hot water (at least 120-140 degrees Fahrenheit) is essential to kill and remove dust mites.

While it is impossible to completely eliminate dust mites from a home, taking these steps can significantly reduce their numbers and help manage allergies and asthma symptoms.

Dead skin cells

The presence of dead skin cells in household dust can have implications for human health. For example, it can cause allergic reactions in some individuals. Additionally, dust mites feed on the skin cells and their droppings contain enzymes that can be released when they come into contact with moisture, potentially causing inflammation and havoc in human cells when inhaled.

To reduce the presence of dead skin cells and dust mites in the home, regular cleaning, including vacuuming, wiping down surfaces, and washing bedding and blankets in hot water, is recommended. Using a vacuum with a high-efficiency particulate air (HEPA) filter can help capture smaller particles, and dusting with a damp cloth can reduce exposure to chemicals and allergens found in dust.

While dead skin cells are a significant component of dust, it is important to note that dust is composed of various other materials as well, including fibres, pollen, hair, bacteria, and insect body parts. The exact composition of dust can vary depending on location and the presence of pets or outdoor pollutants.

Road dust

Dust is composed of a variety of materials, and road dust is no exception. It is made up of deposits of vehicle and industrial exhaust gases, particles from tyre and brake wear, dust from paved roads or potholes, and dust from construction sites.

The small size of the particles in road dust means they can be easily inhaled, causing a range of health issues. These include mild to moderate respiratory issues like allergies, coughing, and irritated eyes and skin. With prolonged or excessive exposure, more serious health issues can occur, including life-threatening respiratory illnesses like pneumoconiosis, silicosis, COPD, or lung cancer.

The control of road dust is a challenge, but some methods to reduce it include proper road construction and maintenance, such as using gravel or soil adhesives to create a hard surface, and regular watering of dirt roads to increase moisture content and prevent particles from becoming airborne. Mechanical methods such as street sweepers, vehicles equipped with vacuum cleaners, and water sprayers can also be used to suppress road dust.

Atmospheric dust

Road dust, for example, is a significant source of air pollution, consisting of vehicle and industrial exhaust gases, particles from tire and brake wear, and construction site debris. Dust from roads and construction sites can easily become airborne, especially in windy and dry conditions, leading to an increase in atmospheric dust.

The composition of atmospheric dust can vary depending on the local environment. For instance, volcanic eruptions can introduce volcanic ash into the atmosphere, while pollution from industrial activities can also contribute to atmospheric dust. In some regions, drought conditions can lead to the drying up of wetlands and lakes, transforming them into centers of dust generation due to wind erosion.

Additionally, atmospheric dust can contain particles from human and animal sources. Dead skin cells, hair, and clothing fibers can become airborne and contribute to atmospheric dust, especially in urban areas with high human populations.

Understanding the sources and composition of atmospheric dust is crucial for managing air quality and mitigating potential health risks associated with airborne particles.

Allergens

Dust allergies are a common type of allergy that is caused by exposure to dust mites, which are tiny organisms that live in household dust. These microscopic pests, which are related to spiders and ticks, feed on organic matter such as human and animal skin cells, as well as the moisture in the air. Dust mites are found all across the world and are present in around 84% of US households. They thrive in warm, humid environments, making bedding, mattresses, carpets, curtains, and upholstered furniture ideal habitats for them.

People with dust mite allergies may experience symptoms such as sneezing, a stuffy or runny nose, itchy and watery eyes, and a sore throat. In more severe cases, a dust mite allergy can lead to persistent sneezing, congestion, facial pressure, an eczema flare-up, or even an asthma attack. The allergy can also cause or worsen asthma symptoms, including wheezing and difficulty breathing. It is important to note that dust mite allergy symptoms can be similar to those of a common cold or upper respiratory viral illnesses, so it is recommended to consult a healthcare provider for an accurate diagnosis.

To prevent dust mite allergies, it is crucial to minimise exposure to dust mites. While it is challenging to eliminate dust mites completely, maintaining a clean and dry environment can help reduce their population. This includes regular vacuuming and dusting, using allergen-proof bedding, and keeping humidity levels below 50%. Washing bedding in hot water or freezing it overnight can also help kill dust mites. Additionally, using HEPA filters in vacuum cleaners and air conditioning units can effectively trap dust mites and other allergens.

For individuals with dust mite allergies, limiting exposure to allergens is the first step in prevention. Over-the-counter or prescription medications, such as antihistamines, nasal steroid sprays, and oral decongestants, can help alleviate symptoms. In some cases, immunotherapy and prescription medications may be recommended for more advanced treatment options.

Frequently asked questions