The evil 13
13 common indoor air quality conditions
that plague us all
Elevated RH
Relative humidity is simply a measurement of the amount of moisture in air compared to the maximum amount of moisture that same air could hold at a given temperature and pressure, example: if your humidity is at 50%RH then your air is about 1/2 full in regards to the amount of moisture it can hold, this is a normal indoor level.
If your humidity is at 65%RH it is about 65% full in regards to the amount of moisture it can hold, levels this high can support mold growth, dust mite growth, and you might experience condensation problems on cold surfaces such as AC registers. At 100% humidity the air cannot hold the moisture anymore and that humidity or air born moisture starts to condensate or change from humidity to water droplets. Humidity below 30% can cause drying of the lips and the mucous membranes in the throat, nose, or sinuses, this in turn causes irritation and some believe it may even lead to a higher likelihood of contracting colds because of damage to the membranes. It an also cause static electricity build up in offices that can in turn put computers at risk of lose of data. Keep your humidity between 30% and 60%RH.
Negative pressure
Sometimes negative pressure in homes and other buildings causes humid outdoor air to be pulled into buildings in hot humid environments, and radon to be pulled into buildings in environments where radon is problematic, also negative pressure can pull dangerous levels of carbon monoxide out of gas burning devices. Smelly crawl space or attic air can also be pulled into such buildings. One of the possible causes of negative pressure is leaky AC ducts in crawl spaces and attics because the ducts leaks the buildings air outdoors resulting in less air pressure indoors than outdoors, another cause of negative pressure can be the use of ventilation fans and hoods vented to the exterior. If not corrected negative pressure can cause serious problems in areas with radon or humidity thus positive pressure is desirable in hot humid environments and in areas with radon problems. In temperate climates when it is cool or cold outside positive indoor pressure is to be avoided because it can push the buildings humid indoor air into walls where it cools and forms condensation. Inspectors often use digital manometers of smoke from smoke pens to detect negative pressure.
Water damaged building materials
When leakage occurs indoors it often results in mold and decay, this in turn can cause allergenic particles such as mold spores to be released into your air. Home inspectors, mold inspectors and other building investigators may use a moisture meter to detect moisture hidden inside water damaged building materials.
Infrared cameras can also be used to detect moisture hidden inside walls and other areas by measuring very slight temperature differentials between cooler wet surfaces and warmer dry surfaces.
Physical and psychological stressors
Stressors play an important role in building occupants resistance to and perception of indoor air quality problems. According to the Technical Guide to the Investigation of Indoor Air Quality in Office Buildings stressors are "environmental parameters, such as lighting, noise, vibration, and ergonomics. Thermal comfort also plays an important role in building occupants resistance to and perception of indoor air quality problems.
According to the above referenced source thermal comfort is "A state of mind in which a person feels satisfaction with the thermal environment. The factors affecting thermal comfort are air temperature, stratification, mean radiant temperature, air motion, relative humidity, activity level, and clothing." Ventilation rate is also an important factor to consider. Ventilation rate is the amount of outside air that is supplied to the interior space.
Dust dust mites and particulates
Air contaminated with excess particles can also cause negative reactions. Some particles cause direct irritation when levels are elevated. In the case of household dust people do not typically have a direct allergenic or irritation related reaction to common dust. Common dust is as much as 80% dead human skin cells, you have serious problems. When people have allergic reactions to common household dust it is not the dust causing the problem but allergenic proteins found in dust mite feces. Particles counters can be used to measure airborne particulates, particle counters are highly sensitive scientific instruments that use an internal laser to count particles passing through it that are of a predetermined size range. Many pen / asp mold spores are between 2 and 10 microns in diameter, many other spores are around 10 to 15 microns in diameter, thus areas with high levels of particles in this size range may have a mold problem that should be verified with air sampling. These devices cannot identify the particles they count, however, some of the particles they count may be mold spores because they verify the particular size of the particles that are counted.
Carbon dioxide
High carbon dioxide levels are not typically a direct threat to human health in home and commercial properties. High carbon dioxide levels usually indicate a lack of adequate outdoor air being introduced into the building. Dust, chemicals, body odors and other indoor air pollutants often build up along with carbon dioxide in poorly ventilated buildings, and it is these other indoor pollutants that result in indoor air quality complaints and health complaints. According to Parat and others “A properly maintained and operated mechanical ventilation system can reduce indoor Bioaerosols concentrations by limiting infiltration of outdoor Bioaerosols and by diluting those from outdoor sources” ( Parat et al., 1994, 1996 ).
According to American Society of Heating Refrigerating and Air Conditioning Engineers ASHRAE 62-89 Outdoor air supply into the building should be at least 20 cubic foot per min per person in offices and thus help maintain carbon dioxide levels below 1000 ppm. Newer requirements recommend levels no more than 700 ppm higher than outdoor carbon dioxide levels. Outdoor air that is being introduced into a building must meet the US EPA National Primary Ambient Air Quality Standards is short it must be clean or it must be properly filtered.
Carbon monoxide
WARNING: Carbon monoxide can rapidly rob your bloods ability to properly absorb oxygen thus it can be deadly. If carbon monoxide levels at your property are dangerously high then emergency measures such as immediate evacuation may be deemed necessary. Even if slightly elevated further investigation by a qualified, licensed, specialist is recommended and appropriate repairs or other measures may be needed. The leading cause of deaths from carbon monoxide poisoning in homes is automobile exhaust escaping from garages, however improper combustion of fuel in gas appliances, improper ventilation of combustion gases to the exterior, and cracked heat exchangers are also important sources of carbon monoxide exposure.
At low concentrations the health effects are fatigue in healthy people and chest pain in persons with heart disease. At higher concentrations it causes impaired vision and coordination problems, headaches, dizziness, confusion, nausea. It can cause flu like symptoms that clear up after leaving home. Carbon monoxide is fatal at very high concentrations.
Average levels in homes without gas stoves 0.5 to 5 ppm.
Levels near properly adjusted gas stoves are 5 to 15 ppm. Near poorly adjusted stoves 30 ppm or higher. The above information is from epa.gov/iaq/co.html
Voc’s
Volatile organic compound also known as VOC's are common indoor pollutants composed of organic chemicals that evaporate into the air easily, they often cause chemical odors, respiratory irritation, headache, and other indoor air quality related complaints. At certain high levels they can be dangerous. These chemicals are released by paints, paint thinners, varnish, new carpets, new cabinets and furniture that contains particle board, household cleaners and air fresheners, fuel gas, improperly vented combustion devices, photocopier machines, blueprint machines, and many other sources.
Formaldehyde
Formaldehyde is a common indoor air quality problem, it is primarily used to produce glues used in the manufacture of particle board, wood veneers, wood furniture, plywood, and other wood products.
And spray-on insulating foams. These resins slowly give off formaldehyde over time, formaldehyde is one of the more common indoor air pollutants. At concentrations above 0.1 ppm in air, formaldehyde can irritate the eyes and mucous membranes, resulting in watery eyes. If inhaled, formaldehyde at this concentration may cause headaches, a burning sensation in the throat, and difficulty breathing, as well as triggering asthma symptoms.
Sewer gas
Hydrogen sulfide it the gas that produces rotten egg or sulfur like odors in well water, sewer systems, rotten eggs, and other areas where water and organic compounds have a lack of oxygen. Hydrogen sulfide odors may lead to complaints of foul odors and also eye & throat irritation cough and shortness of breath. According to wikipedia ".0047 ppm is the recognition threshold, the concentration at which 50% of humans can detect the characteristic rotten egg odor of hydrogen sulfide."
10 to 15 ppm is the borderline concentration for eye irritation.
No2
Nitrogen dioxide is composed of nitrogen and oxygen atoms, incomplete combustion in vehicles or gas burning appliances can create this pollutant and improper venting of such combustion gases from gas appliances, loading docks, and parking garages, can result in the gas entering into the indoor environment. Nitrogen dioxide is a respiratory irritation.
O3
Ozone is a fresh smelling oxygen molecule composed of 3 oxygen atoms, the oxygen we breathe is made of just two oxygen molecules. In the upper atmosphere ozone blocks out harmful UV light thus protecting living organisms below, at ground level ozone is an air pollutant that can have harmful effects on our respiratory system in fact ozone is a constitute of smog pollution. Asthmatics are especially at risk from the effects of ozone exposure.
Despite claims of safe levels of fresh smelling ozone emitted by ozone producing machines, some ozone machines have been found to produce ozone at levels that may result in respiratory irritation in some persons. It is true that ozone can break down smoke, odors, and other indoor air quality contaminates but the break down product follow the most basic laws of physics and thus do not disappear for existence but instead these products have end up in the air where some of them can serves as irritants to sensitive persons.
· According to the EPA some health effects of overexposure to ozone are:
· Decreases in lung function
· Aggravation of asthma
· Throat irritation and cough
· Chest pain and shortness of breath
· Inflammation of lung tissue
· Higher susceptibility to respiratory infection
For more info please visit: epa.gov/iaq/pubs/ozonegen.html
Radon
Last but not least on or list of 13 sinister Indoor Air Quality (IAQ) problems is radon, a colorless odorless gas that finds its way into buildings through cracks in the foundations. If a building is negatively pressurized then that negative pressure can cause radon to be actively sucked into the building. Radon is unheard of in some areas such as South Florida, in other areas such as New England radon is common. Radon is a carcinogen or cancer causing agent. Often persons living with radon will have no clue that the problem exists till it is to late. Even in non smokers radon causes lung cancer. If you know of a household where a non smoker developed lung cancer then you should suggest that the home or the victim’s previous residence be tested for radon gas. According to the EPA and the segron general radon is responsible for 15,000 deaths a year.
Daryl Watters has a bachelors degree in education for teaching biology and general science and is a certified mold inspector, certified home inspector, and certified indoor environmentalist providing building inspections in South Florida since 1993.
For more information visit www.floridamoldinspectors.us www.florida-mold-inspection.com www.freemoldinspectionreporting.com www.moldinspectionreport.com
To set up an appointment just call us at:
1 (888) 381-6651 
