What is House Dust?
House Dust is a broad term to describe the ever-changing and always present combination of unknown substances we see in our homes.
House Dust is the combination of particles that results from the natural decomposition of the contents of our homes, mixed with dust that infiltrates from the outside. Dust is the most visible and therefore is a primary indicator of poor Indoor Air Quality. In many cases, this leads to multiple allergic symptoms and related health issues.
What is in house dust?
The composition of house dust has changed over time and the components today may be quite different, from one home to the next. For the most part, you may see textile fibres, insect parts, pet dander, human and animal hair, food leftovers, pollen grains, mould spores, bacteria, skin flakes, insulation, sand, and the ever-present dust mite and its fecal material.
What increases the amount of dust in a house?
Homes with carpets often have a higher level of house dust. draperies, ruffled items, knickknacks, books, magazines, pets, upholstered furniture, animals and pillows, and fireplaces increase levels of dust. Inadequate cleaning or cleaning with an inadequate filtering system, high traffic levels, location of the house, type of yard, and their condition of the central air system all contribute to the amount of dust in your home. For example, if you are in a new neighbourhood where there is a lot of construction and the yards without grass, you will have more dust in your home.
Dust = Respirable Particles
Dust and airborne particulates can be irritating to the upper respiratory system and will adversely affect individuals with existing allergies, asthma, and respiratory diseases. Long term exposure to dust and airborne particulate may also pose a risk for people who currently do not experience respiratory symptoms.
Recognize sources of pollution in your home
Air-borne pollutants are either biological (mould, dust mites, pollen, animal dander) or come from other sources (gases or chemical particles released by furnishings, carpets, construction materials, unvented appliances, renovation activities including dust from lead paint, poorly-maintained heating systems, humidifiers and dehumidifiers). A Heat Recovery Ventilator (HRV)works to reduce concentrations of indoor pollutants.
It’s important to consider the effects of different size dust particles in your home…
PARTICLES are usually measured in microns: (1 micron=1 millionth of a meter or 1/25,000th inch).
The human body has defences which can protect against particles larger than 10 microns, however, particles smaller than 10 microns can enter breathing passages and penetrate deep into the lungs.
PM10 – respirable particles having an aerodynamic diameter <= 10 microns. Particles < 5 microns can penetrate into the lower respiratory tract.
PM2.5 -particles with an aerodynamic diameter <=2.5 microns. PM2.5 particles settle slowly (several hours to several days) – particles can cover hundreds of miles. Particles penetrate deep into lungs.
There are two categories of indoor air pollutants that can affect the quality of air in a home: particulate matter and gaseous pollutants, also known as VOC’s, or Volatile Organic Compounds. The best way to address these gaseous pollutants id with a Heat Recovery Ventilator, otherwise known as an HRV
Particulate matter is made up of microscopic solids, liquid droplets, or it can be a mixture of solids and liquid droplets suspended in the air. Also known as particle pollution, Particulate matter is made up of a number of components, including acids such as nitric and sulphuric acids, organic chemicals, metals, soil or dust particles as well as biological contaminants.
Some of the particles that can be found in a home are:
- Dust as solid PM or fumes and smoke, which are mixtures of solid and liquid particles.
- Biological contaminants, including viruses, bacteria, pollen, moulds, dust mite and cockroach body parts and droppings, and animal dander.
How to reduce particulate contaminants in your home…
The Answer: Mechanical Ventilation Systems
Heating, Ventilation and Air Conditioning (HVAC) systems perform many functions, including, but not limited to these important tasks:
- They bring fresh air indoors
- They vent stale air outside
- They circulate the air throughout the building; and
- They control temperature and humidity levels.
Mechanical filters can be installed on your furnace or as part of the ventilation system. . Filters must be replaced according to the manufacturer’s instructions in order to be effective. PCO Models use Photo Catalytic Oxidization to destroy VOC’s and are usually equipped with a high efficiency particulate filter. They can be a part of the ventilation system.
Ion generators use static charges to trap particles and are only available as portable units. Some ion generators also produce ozone as a by-product, which is a known lung irritant. Hybrid models are air cleaners that incorporate two or more of the air cleaner types mentioned above into a single product and are becoming more and more common.