Indoor Air Quality

In an effort to make our homes more energy efficient, we have made our homes tighter.  As a result, our indoor air can be more polluted than the air outside.  Familiarize yourself with common indoor pollutants and what you can do to minimize them.

courtesy Wikipedia.org

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Indoor Air Quality (IAQ) deals with the content of interior air that could affect health and comfort of building occupants. the IAQ may be compromised by microbial contaminants (mold, bacteria), chemicals (such as carbon monoxide, radon), allergens, or any mass or energy stressor that can induce health effects. Recent findings have demonstrated that indoor air is often more polluted than outdoor air (albeit with different pollutants) although this has not changed the common understanding of air pollution. In fact, indoor air is often a greater health hazard than the corresponding outdoor setting. Using ventilation to dilute contaminants, filtration, and source control are the primary methods for improving indoor air quality in most buildings.

Techniques for analyzing IAQ include collection of air samples, collection of samples on building surfaces and computer modeling of air flow inside buildings. the resulting samples can be analyzed for mold, bacteria, chemicals or other stressors. these investigations can lead to an understanding of the sources of the contaminants and ultimately to strategies for removing the unwanted elements from the air.


Common pollutants

Radon
Radon is the invisible, radioactive atomic gas that results from radioactive decay of some forms of uranium that may be found in rock formations beneath buildings or in certain building materials themselves. Radon is probably the most pervasive serious hazard for indoor air in the United States and Europe, probably responsible for tens of thousands of lung cancer deaths per annum. there are relatively simple tests for radon gas, but these tests are not commonly done, even in areas of known systematic hazards. Radon is a very heavy gas and thus will tend to accumulate at the floor level. Building materials can actually be a significant source of radon, but very little testing is done for stone, rock or tile products brought into building sites. the half life for radon is 3.8 days indicating that once the source is removed, the hazard will be greatly reduced within a few weeks.

Molds and other allergens
these biological chemicals can arise from a host of means, but there are two common classes: (a) moisture induced growth of mold colonies and (b) natural substances released into the air such as animal dander and plant pollen. Moisture buildup inside buildings may arise from water penetrating compromised areas of the building envelope or skin, from plumbing leaks, from condensation due to improper ventilation, or from ground moisture penetrating a building part. In areas where cellulosic materials (paper and wood, including drywall) become moist and fail to dry within 48 hours, mold mildew can propagate and release allergenic spores into the air.

Mold

In many cases, if materials have failed to dry out several days after the suspected water event, mold growth is suspected within wall cavities even if it is not immediately visible. Through a mold investigation, which may include destructive inspection, one should be able to determine the presence or absence of mold. In a situation where there is visible mold and the indoor air quality may have been compromised, mold remediation may be needed. Mold Testing and Inspections should be done by an independent investigator to avoid any conflict of interest and to insure accurate results. Beware of free mold testing, Mold Testers and Inspectors should have no relation to any remediation companies.

there are some varieties of mold that contain toxic compounds (mycotoxins). However, exposure to hazardous levels of mycotoxin via inhalation is not possible in most cases, as toxins are produced by the fungal body and are not at significant levels in the released spores. the primary hazard of mold growth, as it relates to indoor air quality, comes from the allergenic properties of the spore cell wall. More serious than most allergenic properties is the ability of mold to trigger episodes in persons that already have asthma, a serious respiratory disease.

Indoors, mold growth can be inhibited by keeping humidity levels below 50% and by eliminating any water leaks. Moisture problems causing mold growth can be direct such as a water leaks and/or indirect such as condensation due to humidity levels.Mold is always associated with moisture, in order to resolve a mold problem moisture problems must be reduced.

Carbon monoxide
One of the most acutely toxic indoor air contaminants is carbon monoxide (CO), a colorless, odorless gas that is a byproduct of incomplete combustion of fossil fuels. Common sources of carbon monoxide are tobacco smoke, space heaters using fossil fuels, defective central heating furnaces and automobile exhaust. Improvements in indoor levels of CO are systematically improving from increasing numbers of smoke-free restaurants and other legislated non-smoking buildings. By depriving the brain of oxygen, high levels of carbon monoxide can lead to nausea, unconsciousness and death. According to ACGIH (American Conference of Governmental Industrial Hygienist),TWA (Time Waited Average) limit for CO (630-08-0) is 25 ppm.

Carbon dioxide
Carbon dioxide (CO2) is a surrogate for indoor pollutants emitted by humans and correlates with human metabolic activity. Carbon dioxide at levels that are unusually high indoors may cause occupants to grow drowsy, get headaches, or function at lower activity levels. Humans are the main indoor source of carbon dioxide. Indoor levels are an indicator of the adequacy of outdoor air ventilation relative to indoor occupant density and metabolic activity. To eliminate most Indoor Air Quality complaints, total indoor carbon dioxide should be reduced to below 600 ppm above outdoor levels. NIOSH considers that indoor air concentrations of carbon dioxide that exceed 1,000 ppm are a marker suggesting inadequate ventilation. ASHRAE recommends that carbon dioxide levels not exceed 700 ppm above outdoor ambient levels.
 

the three types of indoor air pollutants as categorized by the Environmental Protection Agency (EPA).
 

  1. Particles are small pieces of matter that float in the air.  Particulate matter can be in the form of either solid or liquid.  the smallest particles pose the most risk from exposure because they can be drawn deeply into the lungs increasing one's risk of both lung damage and lung cancer.  Examples of small particulates include cigarette smoke, viruses, bacteria, cleaning products, and pesticides.  Larger particles do not enter the lungs as deeply, but can still cause allergic reactions.  Examples of large particulate matter include pollen, pet dander, and mold spores.

  2. Gaseous pollutants are present in every household.  Exposure can cause allergic reactions and irritate the eyes, nose, and lungs.  More serious conditions such as cancer, liver damage, and compromised immune systems have been linked to long-term exposure of gas pollutants.  Examples of gas pollutants include cigarette smoke, cleaning products, fumes from carpets, and fragrances.

  3. Radon exposure is responsible for thousands of cancer deaths each year.  the greater your exposure, the greater your risk.  Radon is a naturally occurring radioactive gas; it is emitted from groundwater, natural gas, rock, and soil as well as brick, concrete, and stone.

FYI

Cigarette smoke contains carbon monoxide which can desensitize smokers to its presence.  Everyone should have a carbon monoxide detector, but it can be especially important for smokers.


Did you know?

Scientists at NASA discovered that houseplants clean the air in tightly sealed chambers.  Additionally, they found that the plants cleaned the air more efficiently over time and reduced mold and bacteria concentrations by 50 to 60 percent.  - Organic Housekeeping by Ellen Sandbeck

Tips for reducing indoor air pollution

Prevention
  • Take your shoes off at the door.  the surfaces you walk upon outdoors may contain pesticides, fertilizers, petroleum products, or any other number of chemicals that you do not want in your home.  Removing your shoes will limit the amount you bring into your home.
  • Smoke outside only.
  • Avoid the use of unvented space heaters.
  • Have your furnace and chimney inspected annually to ensure they are in proper working order.
  • Routinely clean and maintain gas appliances and pipes to head off potential leaks.
  • Do not burn candles that contain lead in their wicks or scented using synthetic fragrances.
  • Avoid using products that emit harmful fumes.
  • Address water leaks in a timely fashion and mop up puddles immediately.
  • Maintain gutters and downspouts to ensure proper drainage.
  • Dispose of musty furnishings.
Maintenance
  • Use green cleaning products.
  • Take advantage of temperate days and open the windows to air out your home.
  • Use a vacuum that contains a HEPA filter to remove allergens.
  • You may choose to use an air filtration system or an air purifier, but some models emit ozone.
  • Replace air filters in the central air/heating system monthly.
  • If you use a humidifier, clean it daily according to the manufacturer's instructions.
  • Place houseplants throughout the home.  they clean the air naturally and add beauty as well.
  • Utilize a carbon monoxide detector to alert you of its presence.

For addition information on indoor air pollution


Green tips of the month: Water

As adults, up to 60% of our bodies are composed of water.  We need to drink 8 glasses daily to help us function properly.  With that in mind, consider the following to help reduce, reuse, and recycle when consuming water. 
  • Reduce the amount of bottled water you purchase and consider using a water purification system that attaches to the tap.
  • Reuse containers.  Purchase water bottles that can be reused and refilled instead of buying bottled water.
  • Recycle the plastic bottles when you do consume bottled water.