A)Overall Health Effects
Many of us experience some kind of air pollution-related symptoms such as watery eyes, coughing, or wheezing. Even for healthy people, polluted air can cause respiratory irritation or breathing difficulties during exercise or outdoor activities. Your actual risk depends on your current health status, the pollutant type and concentration, and the length of your exposure to the polluted air.
People most susceptible to severe health problems from air pollution are:
- Individuals with heart disease – such as coronary artery disease or congestive heart failure
- Individuals with lung disease – such as asthma, emphysema or chronic obstructive pulmonary disease (COPD)
- Pregnant women
- Outdoor workers
- Children under age 14, whose lungs are still developing
- Athletes who exercise vigorously outdoors
High air pollution levels can cause immediate health problems:
- Aggravated cardiovascular and respiratory illness
- Added stress to heart and lungs, which must work harder to supply the body with oxygen
- Damaged cells in the respiratory system
Long-term exposure to polluted air can have permanent health effects:
- Accelerated aging of the lungs
- Loss of lung capacity
- Decreased lung function
- Development of diseases such as asthma, bronchitis, emphysema, and possibly cancer
- Shortened life span
Health Effects from Specific Pollutants
Ground-level ozone is formed when volatile organic compounds (VOCs) and oxides of nitrogen (NOx) react with the sun’s ultraviolet rays. The primary source of VOCs and NOx is mobile sources, including cars, trucks, buses, construction equipment and agricultural equipment.
Ground-level ozone reaches its highest level during the afternoon and early evening hours. High levels occur most often during the summer months. It is a strong irritant that can cause constriction of the airways, forcing the respiratory system to work harder in order to provide oxygen. It can also cause other health problems:
- Aggravated respiratory disease such as emphysema, bronchitis and asthma
- Damage to deep portions of the lungs, even after symptoms such as coughing or a sore throat disappear
- Wheezing, chest pain, dry throat, headache or nausea
- Reduced resistance to infection
- Increased fatigue
- Weakened athletic performance
Particulate Matter (PM)
Particulate Matter is a complex mixture that may contain soot, smoke, metals, nitrates, sulfates, dust, water and tire rubber. It can be directly emitted, as in smoke from a fire, or it can form in the atmosphere from reactions of gases such as nitrogen oxides.
The size of particles is directly linked to their potential for causing health problems. Small particles (known as PM2.5 or fine particulate matter) pose the greatest problems because they can get deep into your lungs and some may even get into your bloodstream. Exposure to such particles can affect both your lungs and your heart.
Scientific studies have linked long-term particle pollution, especially fine particles, with significant health problems including:
- Increased respiratory symptoms, such as irritation of the airways, coughing or difficulty breathing
- Decreased lung function
- Aggravated asthma
- Development of chronic respiratory disease in children
- Development of chronic bronchitis or chronic obstructive lung disease
- Irregular heartbeat
- Nonfatal heart attacks
- Premature death in people with heart or lung disease, including death from lung cancer
Short-term exposure to particles (hours or days) can:
- Aggravate lung disease causing asthma attacks and acute bronchitis
- Increase susceptibility to respiratory infections
- Cause heart attacks and arrhythmias in people with heart disease
Even if you are healthy, you may experience temporary symptoms, such as:
- Irritation of the eyes, nose and throat
- Chest tightness
- Shortness of breath
B)Assessing the potential health risks of basements
Basements sure have come a long way. These days, we convert them into enjoyable, comfortable living spaces. Whatever purpose you give your basement, though—office, game room, home cinema—it’s vital that you make sure it offers a healthy environment for all occupants.
Features and factors to keep in mind
Basements have features that expose the people living in them to certain risk factors, like mould, carbon monoxide, volatile organic compounds, and radon.
Mould: it’s never innocuous
Mould is made up of microscopic fungi that grow in humid materials. It can be black, white or another colour, and can smell musty or earthy. To proliferate, mould needs moisture and a material it can live in: wood, paper, carpeting, etc. It develops in areas where:
- water condenses on surfaces because of excessively humid air, a lack of ventilation or excessively low temperatures;
- water infiltrates due to leaks from the roof or plumbing, a breach in the home’s exterior cladding, cracks in the foundations, or flooding.
These conditions occur frequently in basements.
Mould releases spores into the air, which everyone in the house can breathe in. This can lead to health problems such as:
- irritation of the eyes, nose and throat;
- coughing and phlegm buildup;
- shortness of breath; and
- asthma symptoms or allergic reactions.
To find out more:
- Effects of Mould on Health (Health Canada): www.hc-sc.gc.ca/ewh-semt/air/in/poll/mould-moisissure/effects-effets-eng.php
- Residential Indoor Air Quality Guidelines: Moulds: Health Canada
- Measuring and controlling humidity (CAA-Quebec Tips & Tricks): Excess humidity: Condensation is an S.O.S.!
- Cleaning surfaces affected by mould (CAA-Quebec Tips & Tricks): Mould: Get rid of it for good!
Carbon monoxide: a silent enemy
Carbon monoxide (CO) is an invisible, odourless toxic gas that does not irritate the throat—so detecting its presence is impossible. It may be “silent,” but it can kill.
CO builds up rapidly in the blood, inhibiting its ability to carry oxygen throughout the body. The longer one is exposed to it, the worse the damage:
- Mild exposure: flu-like symptoms, like headaches, runny nose, eye irritation, etc.
- Medium exposure: drowsiness, dizziness, vomiting, disorientation, confusion.
- Severe exposure: loss of consciousness, brain damage, death.
Carbon monoxide is released in cases of incomplete combustion of organic matter or when an appliance (e.g., a heater or generator) or vehicle burns fuel such as gasoline, propane or natural gas, wood, heating oil, etc. For this reason, if your home is equipped with a fuel-burning appliance, or has an attached garage where vehicles are started, you must install a certified carbon monoxide detector. Note that smoke detectors do NOT detect carbon monoxide, even in high concentrations.
To find out more:
- Read this document from the Quebec Health and Social Services Ministry on the effects of CO and how to detect the gas;
- Read the CAA-Quebec Tips & Tricks instalment on the risks of having a garage attached to an inhabitable part of your house.
Volatile organic compounds (VOC): pollution at home
Volatile organic compounds (VOCs) are chemicals that can be released into the indoor air of homes. They affect air quality and, in turn, the health of residents who breathe that air, especially if a room is poorly ventilated, which is often the case in the basement.
Cigarette smoke, paints, varnishes, glue, floor coverings, cleaners, air purifiers, furniture, combustion gases emitted by heating appliances and vehicles in the garage—the sources of VOCs are legion. Their most frequently observed consequences on health are various types of irritation, allergies, and central nervous system disorders.
According to a document published by Canada Mortgage and Housing Corporation (CMHC), chemical pollutants in the home can lead to:
- acute reactions generally caused by accidental short- or medium- term exposure; and
- chronic reactions related to prolonged exposure to low concentrations of substances.
Because of our harsh climate, our homes are built more air- and watertight—which means they trap more moisture and contaminants potentially toxic to our health. This is why a controlled mechanical ventilation system—i.e., an air exchanger, which is designed to completely replace the air in a home every three hours—is required in new homes. Another good idea is to seek out green products that contain no chemical compounds.
To find out more:
- Sections 2.2 and 6 of the CMHC document “Air Quality in Interior Environments,” which cover chemical contamination of indoor air and various ways of preventing it.
- Je me méfie des COV (published by Écohabitation, in French).
- Sustainable development in housing (CAA-Quebec Tips & Tricks).
NB : bien que le site ecohabitation.com ait sont pendant anglo, ecohome.net, il n’y a pas d’équivalent précis de la page «Je me méfie des COV».
Radon: a radioactive gas
Hard as it may seem to believe, your home can contain radioactive gases, like radon, which is produced by the natural decay of uranium in the Earth’s crust. It is colourless and odourless, and can build up to high concentrations in a closed space like a basement.
A house can act like a vacuum, sucking up underground gases. Radon can seep in through any opening that is in contact with the surrounding soil: cracks in foundation walls and floor slabs, construction joints, gaps around utility lines and supporting studs, floor drains and sump pumps, water inlets, etc. At that point, it constitutes a serious health hazard, especially if exposure is prolonged; the effects are worsened if the people exposed are smokers.
Smokers who are exposed to high concentrations of radon are at significantly greater risk of developing lung cancer:
- An average of 16% of lung cancer cases in Canada are attributable to radon exposure.
- Radon is the second leading cause of lung cancer after exposure to tobacco.
The only way to know whether you have a radon problem is to measure the concentration of the gas in your home. It’s a simple and very inexpensive process.
To find out more:
- Read our comprehensive report on the topic: Radon in the house?
- Talk to a CAA-Quebec residential advisor by calling 514 861-6162 or 1 888 627-6666.
NB : l’hyperlien pointait vers la FAQ sur le radon, qui n’est qu’une partie du dossier spécial sur la radon sur votre site. Nous avons modifié le lien en anglais pour qu’il mène au niveau précédent.
If you plan on renovating your basement for liveability, keep in mind that various other factors can have an impact on your well-being and that of the other members of the household. These include accessibility of safety exits, properly functioning smoke detectors, the intensity of electromagnetic fields (which is largely dependent on the concentration of electronic devices and the quality of your electrical system), and sound insulation. By carefully considering all of these aspects, you should be able to get the most out of these extra living spaces.