Air Quality Testing
Air Quality Testing Methods And Techniques
Typical Testing Techniques Used on Most Air Quality and Environmental Surveys
Indoor air quality is affected by the presence of various types of contaminants present in the air. Some air contaminants are in the form of gases, some are in the form of airborne suspended particulate. The indoor air contaminants floating in the sea of your indoor air quality can range from benign to nuisance to toxic. The toxic contaminants include combustion products (carbon monoxide, carbon dioxide, oxides of nitrogen), Radon, Volatile Organic Compounds (VOCs: household solvents, paint solvents and thinners, gasoline and fuel oil vapors, perfumes and fragrances, etc.), semi-volatile organic compounds, pesticides and herbicides. Other air quality pollutants are found in the form of particulates such as dust, asbestos, soot, and particles from building materials and furnishings, such as fiberglass, gypsum powder, paper dust, lint from clothing, carpet fibers, etc. Problematic airborne suspended bioaerosols frequently found include: mold spores, mushroom spores, pollen, bacteria, insect parts, animal dander, cockroach/rat allergens, dust mites, etc.
Below You Will Find a List and Description of The Many Tools We Use to Analyze Indoor Air Quality
Ultrafine Particulate (p/cc)
Envirotest performed particulate testing to determine the amount of suspended particulate in the environment. Suspended particulate testing is performed utilizing the P-Trak Ultrafine particle counter. The P-Trak detects and counts particles smaller than 0.02 micrometers in diameter.
These particles are the ones that often accompany or signal the presence of a pollutant that is the cause of complaints about indoor air quality. Because the P-Trak provides far greater sensitivity to very small particles than traditional instruments, it can actually be used to locate the source and migration of toxic exhaust gases, malfunctioning office equipment, pinhole leaks in boiler gaskets and a wide variety of other problems including airborne mold spores.
Envirotest performed particulate testing to determine the amount of suspended particulate in the environment. Suspended particulate testing is performed utilizing the P-Trak Ultrafine particle counter. The P-Trak detects and counts particles smaller than 0.02 micrometers in diameter. These particles are the ones that often accompany or signal the presence of a pollutant that is the cause of complaints about indoor air quality. Because the P-Trak provides far greater sensitivity to very small particles than traditional instruments, it can actually be used to locate the source and migration of toxic exhaust gases, malfunctioning office equipment, pinhole leaks in boiler gaskets and a wide variety of other problems including airborne mold spores.
| Typical Pollutant Sizes | |
|---|---|
| Bacteria | .01 to 1.0 Microns |
| Dust | 1.0 to 10 Microns |
| Mold | 1.0 to 10 Microns |
| Hair | 10 to 100 Microns |
| Pollen | 10 to 100 Microns |
| Diesel Particulate | 0.1 to 100 Microns |
The Following are common sources of airborne particulate. This list in by no means exhaustive, but it gives you an idea of the types of things to be aware of when you are looking for the source of contamination.
| Mold | Bacteria |
|---|---|
| Hair | Combustion Exhaust |
| Skin Flakes | Dirty Clothing |
| Cosmetics | Chemicals |
| Perfumes | Caulks and Paints |
| Coughing / Sneezing | Aerosols |
| Excessive Movement | Ions (Rust) |
| Wood Fibers | Smoke |
| Paper Fibers | Thinners /Solvents |
| Tobacco Products | Food |
| Candles | Incense |
Use of candles and incense contribute significant quantities of pollutants to the indoor environment, especially soot, benzene and lead. Due to the variability in candles and incense and their respective emission rates, great uncertainty would exist in a generalized risk assessment. The absence of consumer warnings concerning candle emissions and their potential health effects may contribute to exposure of susceptible individuals to respiratory inflammatory agents, carcinogens and teratogens. Due to the variability in candles and incense and their respective emission rates, great uncertainty would exist in a generalized risk assessment. The absence of consumer warnings concerning candle emissions and their potential health effects may contribute to exposure of susceptible individuals to respiratory inflammatory agents, carcinogens and teratogens.
Diesel particulate matter as found as a results of burning diesel fuel for heat, is part of a complex mixture that makes up diesel exhaust. Diesel exhaust is commonly found throughout the environment and is estimated by EPA's National Scale Assessment to contribute to the human health risk. Diesel exhaust is composed of two phases, either gas or particle and both phases contribute to the risk. The gas phase is composed of many of the urban hazardous air pollutants, such as acetaldehyde, acrolein, benzene, 1,3-butadiene, formaldehyde and polycyclic aromatic hydrocarbons. The particle phase also has many different types of particles that can be classified by size or composition. The size of diesel particulate that are of greatest health concern are those that are in the categories of fine, and ultra fine particles. The composition of these fine and ultra fine particles may be composed of elemental carbon with adsorbed compounds such as organic compounds, sulfate, nitrate, metals and other trace elements. Diesel exhaust is emitted from a broad range of diesel engines; Home heating systems, on road diesel engines of trucks, buses and cars and the off road diesel engines that include locomotives, marine vessels and heavy duty equipment. The most common exposure pathway is breathing the air that contains the diesel particulate matter. The fine and ultra fine particles are respirable which means that they can avoid many of the human respiratory system defense mechanisms and enter deeply into the lung. In the National Scale.
Macro Particulate Sampling P3 Dust Analysis
Envirotest utilizes the SIDEPAK AM510 Personal Aerosol Monitor analyzing and data logging aerosol concentration in real time. This machine is a belt-mountable laser photometer that allows a wide variety of size-selective aerosol inlet conditioners for breathing zone or area measurements with a respirable cyclone or integrated impactors. The results are given in real-time concentrations (mg/m3). Sensor type: 90° light scattering, 670 nm laser diode
The SIDEPAK has an Aerosol concentration range: 0.001 to 20 mg/m3 and can read particle sizes from 0.1 to 10 micrometer (µm). Envirotest performed testing to determine the levels of P3 (0.3 micrometers) aerosols.
Carbon Dioxide (CO2)
Carbon Dioxide levels were analyzed using a TSI Q-Track Plus 8554 Air Quality Monitor with a data logger. CO2 measurements were recorded by the data logger at marked intervals over the course of the monitoring period.. The TSI Q-Track Plus 8554 Air Quality Monitor uses an infrared sensor to analyze for CO2. The CO2 System was calibrated to NIST certified CO2 standards before and after the monitoring period.
As a point of reference, ASHRAE1 recommends levels of 1000 PPMv of CO2 as the acceptable indoor limit1. This value (1000 ppm) corresponds to approximately 15 cubic feet per minute of outside air per person supplied to occupied spaces.
Carbon dioxide is a non-toxic gas. It has beneficial uses and is the "fizz" in carbonated beverages. When frozen, it is "dry ice". At concentrations from of 1,100 ppm to 5,000 ppm carbon dioxide can cause headaches. At extremely high levels of 100,000 ppm (10 percent) people lose consciousness in ten minutes, and at 200,000 ppm (20 percent) CO2 causes partial or complete closure of the glottis.
Levels of 2,500 to 5,000 ppm do not normally occur in structures. Use of any type of non-vented fuel-burning space heater, such as a kerosene, natural gas, or propane heater will result in elevated levels. High levels also can occur when several people are in a poorly ventilated room. Carbon dioxide is commonly used as an indicator of the adequacy of ventilation systems. When the windows and doors are closed, all buildings need ventilation both summer and winter.
In homes, the normally occurring leaks and cracks around windows and doors typically provide this ventilation. New, energy-efficient houses are now so tight that most leaks have been eliminated and some type of ventilation system may be needed.
In commercial buildings the required ventilation is typically provided by a fresh air intake to the heating and cooling system. Unfortunately, many firms have closed the fresh air intake to save energy. Many other systems were installed without fresh air intakes. In older buildings many fresh air exchangers and intakes may either be not working or in need of repair.
The American Society of Heating Refrigerating and Air-Conditioning Engineers, Inc. publishes "ASHRAE Standard 62-1989, Ventilation for Acceptable Indoor Air Quality." This standard specifies that the minimum ventilation rate per person is 15 cubic feet per minute (cfm) of outdoor air. Higher rates are in place for specified applications, i.e., the minimum rate is 60 cfm for a smoking lounge, 20 cfm for a school training shop, and 30 cfm for a hospital operating room. Residential dwellings are covered by a special specification, which is 0.35 air changes per hour, but not less than 15 cfm/person. (Note, additional special requirements are listed in the ASHRAE Standard and the complete standard should be consulted for specific recommendations.)
Since carbon dioxide is produced by human respiration, the amount of carbon dioxide can be easily used as an indicator of the adequacy of fresh air ventilation in occupied buildings. Outdoor levels are approximately 300 ppm. The ASHRAE standard requires that sufficient fresh air be provided to keep the level below 1,000 ppm. The CO2 levels in buildings with sufficient ventilation will range between these two readings.
Buildings with insufficient ventilation will range from 1,000 ppm up. Often the levels will be low in the morning and increase while the building is occupied. In buildings occupied during the day the reading should be taken in mid-afternoon, because this is when the CO2 reaches its highest level. To determine ventilation rates, the carbon dioxide levels inside and outside the building must be measured in parts per million (ppm). The ventilation rate is equal to the value 10,500 divided by the difference in indoor and outdoor CO2 concentration.
The ventilation rate will be in cubic feet per minute (cfm) per person. For example, assume the peak afternoon indoor concentration is 1,000 ppm and the outdoor concentration is 300 ppm. The difference between these two is 700 ppm. Dividing 10,500 by 700 ppm yields a ventilation rate of 15 cfm of outdoor air per person. This equation only works when there is a relatively uniform density of people in the room and when steady-state conditions have been reached. It assumes that the people are engaged in light activities, and that there are no combustion sources in the space.
High levels of carbon dioxide often indicate inadequate ventilation. Persons in buildings with high CO2 levels may complain of burning eyes, tiredness, and headaches. These symptoms can be caused by a combination of carbon dioxide and the many other pollutants that occur in a poorly ventilated space. Complying with the requirements of ASHRAE 62-1989 is one step toward improving the indoor air quality of these buildings.
When too little outdoor air enters a building, pollutants can accumulate to levels that can pose health and comfort problems. Unless special mechanical means of ventilation are designed and constructed into a building to minimize the amount of outdoor air that can "leak" into and out of the building, these buildings may have higher pollutant levels. .
Outdoor air enters and leaves buildings by: infiltration, natural ventilation, and mechanical ventilation. In a process known as infiltration, outdoor air flows into the house through openings, joints, and cracks in walls, floors, and ceilings, and around windows and doors. In natural ventilation, air moves through opened windows and doors. Air movement associated with infiltration and natural ventilation is caused by air temperature differences between indoors and outdoors and by wind.
There are a number of mechanical ventilation devices, from outdoor-vented fans that intermittently remove air from a single room (bathroom vents) to air handling systems that use fans and duct work to continuously remove indoor air and distribute filtered and conditioned outdoor air to strategic points throughout the house. The rate at which outdoor air replaces indoor air is described as the air exchange rate. When there is little infiltration, natural ventilation, or mechanical ventilation, the air exchange rate is low and pollutant levels can increase.
1 ASHRAE Standard 62-1989(1989), "Ventilation for Acceptable Indoor Air Quality"
American Society of Heating, Refrigeration, and Air Conditioning Engineers, Inc., Atlanta, Georgia.
Carbon Monoxide (CO)
The TSI Q-Track Plus 8554 Air Quality Monitor equipped with a datalogger for CO was used to monitor for CO. The TSI Q-Track Plus 8554 uses an electrochemical sensor to analyze for CO. This instrument was calibrated prior to all uses with outside air and daily by utilizing a 100 ppm CO span gas prior to use. Calibration is performed against a known standard to ensure precision and accuracy. Measurements are taken at marked intervals for the duration of the survey.
Carbon Monoxide is odorless, colorless, and highly toxic. It kills by reducing the oxygen supply in the body and is a deadly poison. It adversely affects human health at only a few parts per million and causes death at 250 parts per million (250 ppm). CO produces it's toxic effect by competing with oxygen for hemoglobin molecules in the blood. Since it has a greater affinity for hemoglobin than does oxygen, CO is more readily accepted into the blood stream. Low amounts of CO can cause headaches, while higher levels can be fatal.
Properly installed and maintained heating appliances cause little threat from carbon monoxide. Poorly installed and maintained systems can be deadly. All fossil fuels contain carbon. During the combustion process the carbon in the fuel combines with oxygen in the air. With sufficient oxygen, sufficient turbulence, and at high ignition temperatures, nearly all of the carbon combines with two atoms of oxygen, producing the relatively innocuous carbon dioxide.
Heating appliances are designed to provide excess oxygen, and a clean, properly installed and maintained system will produce primarily carbon dioxide (CO2), a large amount of water vapor, small amounts of carbon monoxide (CO), and a number of other pollutants. These products of combustion from a properly maintained heating system will be vented outdoors through the chimney, and do not pose an undue risk to the building occupants.
When insufficient oxygen is available for complete combustion, one atom of carbon combines with one atom of oxygen and carbon monoxide is produced. If the heating appliance or the venting system is defective, some or all of the carbon monoxide might be circulated into the building, posing an extremely hazardous health risk. A warning sign of heating trouble might be sudden excessive levels of moisture in the building, since water vapor is also produced by combustion of fossil fuels. CO is also a by-product of tobacco smoke and motor vehicle exhaust.
Volatile Organic Compounds (VOCs)
Volatile Organic Compounds (VOCs) are tested with the use of the PpbRae. The PpbRae is the most sensitive hand held VOC monitor available. This machine measures with true parts per billion detection of extremely low level, low vapor pressure and highly toxic VOCs, like paint fumes, rug off-gassing, pesticide residues and isocyanates (polyurethane foam, insulation materials, surface coatings, car seats, furniture, foam mattresses, under-carpet padding, packaging materials, shoes, laminated fabrics, polyurethane rubber, and adhesives, and during the thermal degradation of polyurethane products.) This instrument senses measurements of off-gassing from carpets and fabrics, spot checks for ethylene oxide and formaldehyde.
At room temperature, volatile organic compounds (VOCs) are emitted as gases from certain solids or liquids. These include pesticides, solvents, fuels, plastics, perfumes, cleaning agents, hair sprays, rugs, oven cleaners, dry-cleaning fluids, home furnishings, office materials like copiers, certain printers, correction fluids, graphics and craft materials etc. VOCs are consistently found at higher levels indoors than outdoors. Products used in home, office, school, arts/crafts and hobby activities emit a wide array of VOCs. Pesticides sold for household use are technically classified as semi-volatile organic compounds. Very low airborne levels of these products have been found to cause symptoms like conjunctival irritation, nose and throat irritation, headache, allergic skin reaction, and nausea to sensitive individuals.
The sensor in this instrument is also very helpful in determining the origination of mold in buildings by sensing the microbial volatile organic compounds (mVOCs) in the air.
Percent Relative Humidity (RH)
The TSI Q-Track Plus 8554 Air Quality Monitor and the TSI VELOCICALC air quality meter indicates % Relative Humidity.
a. Relative Humidity
Everyone is familiar with the word "humidity," especially as it applies to one's comfort indoors or outdoors. We can feel the humidity on the hot, sticky days of summer, and we know it is low when static electricity shocks us during cold, dry winters. But few people understand the science behind humidity or what is meant by the more precise term "relative humidity."
The National Oceanic and Atmospheric Administration (NOAA) defines relative humidity as: "A dimensionless ratio, expressed in percent (% RH), of the amount of atmospheric moisture present relative to the amount that would be present if the air were saturated. Since the latter amount is dependent on temperature, relative humidity is a function of both moisture content and temperature. As such, relative humidity by itself does not directly indicate the actual amount of atmospheric moisture present."
For example, if the air contains half as much water vapor as is possible, then the relative humidity reading would be 50% RH. Bear in mind that the warmer the air temperature, the more moisture it can hold, and vise versa. This is an important factor to remember when looking at a particular RH. Using the same example, there is less water vapor at 50% RH (65) than 50% RH (85). Almost every meteorologist and hygrometer expresses humidity in this fashion.
b. Humidity and Comfort
Our comfort, whether we feel warm or cold, is determined, among other factors, by the rate at which moisture is evaporated from our bodies. It is this fact which makes the humid summer day so uncomfortable. When there is already so much moisture in the air that the moisture from our skin evaporates very slowly. Therefore, as we perspire, we feel sticky and are generally uncomfortable. Conversely, if the air is dry, evaporation is much more rapid; the more rapid the evaporation, the cooler we feel.
c. Humidity and Health
Air has a tremendous need for moisture. So when we heat our buildings in the winter (drawing in cold, dry air), this air is going to take moisture from wherever it can. This dry air in our homes and offices not only dries our skin, but also robs the delicate membranes of the nose and throat of their normal moisture. Low humidity may make us more uncomfortable or even subject to various respiratory problems.
However, there may be more effects of both high and low humidity than just discomfort. Studies show that humidity may affect three groups of factors with respect to health:
1. Biological contaminants including bacteria, viruses, fungi, and mites.
2. Pathogens causing respiratory problems including allergic rhinitis and asthma.
3. Chemical interactions including ozone production.
Some of these factors may thrive at low levels of RH while others may prefer high levels of RH.For example, certain bacteria thrive and grow at very low levels of humidity (0-20% RH) while other bacteria grow and thrive at very high levels of humidity (55%-100% RH). Most Fungi remain dormant and do not start growing and thriving until %RH levels rise above 50% RH.
The optimal comfort zone for %RH is roughly between 35-45% RH in the summer months and 25-40% RH in the winter months. By following these guidelines the levels of bacteria, fungi, viruses, respiratory infections, allergic rhinitis and asthma will be kept in check.
d. Humidity and Energy Costs
In winter, heated, non-humidified air may dry out and/or shrink wood framing around doors and window frames. Gaps may occur allowing cold, dry outside air to enter the building. This heat loss causes heating systems to output more dry air. To maintain a certain humidity level, many people compensate with the use of a humidifier. However, since it takes four times as much energy to heat water than to heat dry air, it costs more to maintain a specific humidity level in your building for health and comfort reasons. Monitoring the humidity and careful attention to areas of heat loss will help offset costs.
The benefit of humidified air is its effect on how we feel in certain temperatures. In the winter, the air is dry and the increased evaporation of moisture from our skin makes us feel cold. While 70F is recommended for indoor air temperature, some find that the temperature (when dry) must be near 80F or even higher for us to feel warm enough to be comfortable. The proper humidity will make 70F feel comfortable and may help offset the increased energy it takes to heat humidified air. However, Envirotest does not recommend humidification of any sort during the winter months due to the inherent problems associated with humidifiers. Typically most humidifiers require excessive amounts of cleaning and can increase the humidity to levels where fungi and bacterial growth will occur. Envirotest recommends re-hydrating by consuming more liquids when humidity drops in the winter.
e. Interior Building Humidity
Low humidity in winter may cause drying and/or shrinking of furniture, wood floors and interior trim. Doors and drawers may warp or crack and glue joints in fine furniture and veneers may open or split. Low humidity may rob plants of their moisture, and it may contribute to wall and ceiling cracks. All of these problems may be the result of dry air absorbing moisture from whatever source it can find inside your building.
Buildup of moisture may also cause rotting of wood, mildew and mold. In areas of your building where humidity may be very high, such as Sub-Grade area, laundry rooms, Attics, or Crawl Spaces, it is important to prevent damage to your building from excessive moisture. Additional ventilation may be helpful in the case of excessive Attic humidity
Hydrogen Sulfide (H2S)
Hydrogen sulfide develops from decaying organic matter, from sulfate-reducing bacteria, and from petroleum refining. A magnesium anode rod in a hot water heater can catalyze hydrogen sulfide formation. While extremely high levels of hydrogen sulfide can indeed be harmful, even deadly, H2S is one of those chemicals that can be detected by the nose at an extremely low level. In fact, it can be detected by the human nose at a concentration 1/400 times lower than the threshold for harmful human health effects.
Hydrogen sulfide is irritating to the eyes and respiratory tract. These eye irritations, conjunctivitis, pain, lacrimation, and photophobia may persist for several days. Respiratory tract symptoms include coughing, pain in breathing, and pain in the nose and throat. Repeated exposures to hydrogen sulfide can result in chronic poisoning. Eye irritation, respiratory tract irritation, slow pulse rate, lassitude, digestive disturbances, and cold sweats occur.
The ITX Multi gas monitor Air Monitor equipped with a datalogger for H2S was used to monitor for H2S. The ITX Multi gas monitor uses an electrochemical sensor to analyze for H2S. This instrument was calibrated with 10 ppm H2S span gas prior to use. Calibration is performed against a known standard to ensure precision and accuracy. Measurements are taken at marked intervals for the duration of the survey.
Ammonia (NH3)
Ammonia occurs naturally in the environment and can be found in low levels in air, soil, and water. Typical and natural levels occur between one part and five parts per billion parts of air (ppb). Soil typically contains about 1 to 5 ppm of ammonia. The levels of ammonia vary throughout the day, as well as from season to season. Generally, ammonia levels are highest in the summer and spring.
Ammonia is used in cleaning products, refrigeration, blueprinting machines, and as a neutralizing agent in the petroleum industry. It is also used in the manufacture of fertilizers, nitric acid, explosives, plastics, fuel cells, rocket fuel, synthetic fibers, dyes, and other chemicals. Emissions occur from the processing of guano, purification of refuse, sugar refining, tanneries, and in un-purified acetylene (Sax, 1987; HSDB, 1991).
Ammonia typically enters the body either through breathing and/or ingestion. Typically after inhaling ammonia, most is breathed out again. If ingested, in food or water, ammonia will get into your bloodstream and be carried throughout your body within minutes. Most of the ammonia that enters your body rapidly changes into other non-toxic substances that will not harm you. The rest of this ammonia leaves your body in urine within a couple of days.
The hazardous effects of extreme exposure to ammonia (such as exposure to a dense cloud of ammonia or an accidental spill of concentrated ammonia on skin) would be severe burns on your skin, eyes, throat, or lungs, conjunctivitis, laryngitis, and pulmonary edema, possibly accompanied by a feeling of suffocation (OSHA, 1989).
Persons with asthma may be particularly sensitive to exposure to ammonia. These burns might be serious enough to cause permanent blindness, lung disease, or death. Likewise, if you accidentally ate or drank large amounts of ammonia, you might experience burns in your mouth, throat, and stomach.
Sampling for ammonia was performed by the ITX Multi gas monitor equipped with a datalogger for NH3 which utilizes an electrochemical sensor to analyze for NH3. This instrument was calibrated with 25 ppm NH3 span gas prior to use. Calibration is performed against a known standard to ensure precision and accuracy. Measurements are taken at marked intervals for the duration of the survey.
Ozone (O3)
Ozone is a highly reactive and unstable gas composed of three atoms of oxygen rather than the usual two. Ozone reverts to oxygen quite rapidly particularly on contact with furnishings. Ozone has a pungent odor at 0.01 to 0.02 parts per million of air. At 0.25 ppm, ozone can cause irritation to the eyes and upper respiratory tract. Ozone can be damaging to health in higher concentrations and therefore is included in the list of maximum permitted concentrations of substances (TRGS 900) in the workplace, as a 'substance dangerous to health'. According to this list, a maximum concentration of 0.1 ppm (= 0.2 mg/cm) is permitted in the workplace. This concentration is calculated on the basis of exposure for eight hours in a working week of 40 hours.
Ozone is typically produced in all electrical discharges, e.g. through electric motors, including domestic equipment such as mixers, vacuum cleaners, Ionizing air filters, drills, all electrical tools, copiers, laser printers/faxes and through artificial ultra-violet light (e.g. sun tan lamps).
Ozone is an intensely irritating gas. Ozone can damage the lungs and airways, causing them to become inflamed, reddened and swollen. This response can cause coughing, burning sensations and shortness of breath. Ozone exposure has also been found to increase susceptibility to bacterial pneumonia infection, influenza and other infections.
High ozone levels are particularly dangerous for people with asthma. When ozone levels are high, more people with asthma suffer attacks that require a doctor's visit or use of extra medication. In addition, ozone can significantly worsen the condition of people with chronic bronchitis and emphysema.
Envirotest Utilized the ATI series C16 Portasens II leak detector equipped with a datalogger to perform sampling for O3. This machine utilizes an electrochemical sensor to analyze for O3. This instrument was calibrated with 1 ppm O3 span gas prior to use. Calibration is performed against a known standard to ensure precision and accuracy. Measurements are taken at marked intervals for the duration of the survey.
Nitrogen Oxide (NO2)
Under the high pressure and temperature conditions in an engine, nitrogen and oxygen atoms in the air react to form various nitrogen oxides, collectively known as NOx. Nitrogen oxides, like hydrocarbons, are precursors to the formation of ozone.
Certain members of this group of pollutants, especially nitrogen dioxide (NO2), are known to be highly toxic to various animals as well as to humans. High levels may be fatal, while lesser amounts have been shown to affect the delicate structure of lung tissue. In experimental animals this leads to a lung disease that resembles emphysema in humans. As with ozone, long-term exposure to nitrogen oxides makes animals more susceptible to respiratory infections. Nitrogen dioxide exposure lowers the resistance of animals to such diseases as pneumonia and influenza. Humans exposed to high concentrations suffer lung irritation and potentially lung damage. Increased respiratory disease has been associated with 1st floor Areas exposures.
The human health effects of exposure to nitrogen oxides, such as nitrogen dioxide, are similar to those of ozone. These effects may include:
- Short-term exposure at concentrations greater than 3 parts per million (ppm) can
- measurably decrease lung function.
- Concentrations less than 3 ppm can irritate lungs.
- Concentrations as low as 0.1 ppm cause lung irritation and measurable decreases in lung function in asthmatics.
- Long-term 1st floor Areas exposures can destroy lung tissue, leading to emphysema.
- Children may also be especially sensitive to the effects of nitrogen oxides.
Sampling for Nitrogen Oxide was performed by the ITX Multi gas monitor equipped with a datalogger for NO2 which utilizes an electrochemical sensor to analyze for NO2. This instrument was calibrated with 10 ppm NO2 span gas prior to use. Calibration is performed against a known standard to ensure precision and accuracy. Measurements are taken at marked intervals for the duration of the survey.
Moisture Content
Moisture content was performed using a Protimeter Surveymaster SM. This meter measures water content utilizing radio frequency emissions and through two (2) pin electrodes. The results of testing utilizing the measure mode are in a percentage (%) format representing wood moisture equivalent. The test is performed by actually impinging wall material and writing results as the test is taken. This test is necessary when establishing the exact areas of moisture concentration and origination.
Visible Results For Mold
Inspection for visible mold was performed by trained mold professionals observing visible surfaces and inside wall cavities and other small areas with the assistance of a TESTO-318-1 Boroscope. This machine is able to be inserted into walls and allows the user to visibly detect interior wall cavity utilizing fiber-optic technology with the supplied micro-light. Envirotest performs interior wall cavity observations by removing the electrical outlets and switch plate covers and inserting the probe directly into the wall cavity. Upon entrance into the wall cavity, Envirotest is able to observe any clue of mold activity or obvious mold staining of building materials and interior wall components.
Thermal Imagery
Envirotest utilizes a Flir Thermacam for thermal imaging or thermography of areas of a building. Thermography is the use of an infrared imaging and measurement camera to "see" and "measure " thermal energy emitted from an object.
Thermal, or infrared energy, is light that is not visible because its wavelength is too long to be detected by the human eye; it's the part of the electromagnetic spectrum that we perceive as heat. Unlike visible light, in the infrared world, everything with a temperature above absolute zero emits heat. Even very cold objects, like ice cubes, emit infrared. The higher the object's temperature, the greater the IR radiation emitted. Infrared allows us to see what our eyes cannot.
Infrared thermography cameras produce images of invisible infrared or "heat" radiation and provide precise non-contact temperature measurement capabilities. Envirotest utilizes this camera to pinpoint areas of varying temperatures to identify leaks under walls, floors and ceilings.
Airborne Results For Fungi Samples
1. The Airborne Fungal Levels In Colony Forming Units (CFU/m3):
a. Airborne Fungi Concentrations
Envirotest performed fungi air sampling for identification and enumeration in the areas listed above. All samples are performed using a single stage Anderson Sampler that was calibrated to 28.3 liters per minute using a Mini-Buck primary calibration flow meter. The samples are taken on Sabouraud Dextrose (SD) or Malt Extract Agar (MEA) and then incubated at 280C.
Fungi results are measured in Colony Forming Units (CFU) per cubic meter (m3) of air. Each spore captured typically produces a CFU, these spores then grow in the particular media, the cultured CFU's are then enumerated and identified.
Envirotest recommends that when CFU/m3 levels rise above 250 that corrective action should be taken. When levels of CFU's rise above 500 indoor air quality complaints typically begin