How concerned are you about your health? Have you ever tried to lose weight, eat healthy, and be active in order to prevent or eliminate any health risks? If so, you’ve left out one critical factor, AIR. Yes, you read it right; it’s the air that you breathe. All these factors contribute to your health and well-being. To be healthy, you need take control to eliminate or minimize the “bad” and bring in the “good”. This is possible with your indoor air. So what’s in the air you’re breathing and how can you improve the indoor air quality (IAQ) around you?
What is in the air you’re breathing?
We are constantly exposed to the air that surrounds us regardless if we’re sleeping, working, playing, etc. It’s there 24/7 whether we like it or not. Worst yet, we unconsciously breathe it and bring it into our system with every breath we take. Indoor air pollutants are common but controllable. Sources of indoor air pollutants include, paints, lacquers, paint strippers, aerosol sprays, air fresheners, cleaning supplies, pesticides, building materials and furnishings, copiers, printers, correction fluids, carbonless copy paper, clothes, adhesives, permanent markers, and the list goes on. In other words, they are everywhere! All these Volatile Organic Compounds (VOC) release gases into the air and contribute to Sick Building Syndrome (SBS) and Building Related Illness (BRI) and are the primary cause of IAQ problems. Photo-ionization detectors (PID) are used “to get a simple measure of the joint exposures to several VOCs in indoor air” (Berglund, et al., 1997).
Volatile Organic Compounds (VOC)
Chemicals that emit gas are called volatile organic compounds (VOC). Another common term, Total VOC (TVOC) is a combined variety of organic chemicals that emit gas. They are measured in micrograms per meter cubed (µg/m3) of air, parts per million (ppm), or parts per billion (ppb). Most buildings will have TVOC levels ranging from 100-500 µg/m3 (Aerias). Table 1, below, is used as a guide to compare TVOC results with its symptoms.
Table 1: TVOC and Symptoms
|
TVOC |
Symptoms |
|
< 200 µg/m3 |
No irritation or discomfort expected |
|
200 – 3,000 µg/m3 |
Irritation and discomfort may be possible |
|
3,000 – 25,000 µg/m3 |
Discomfort expected and headache possible |
|
> 25,000 µg/m3 |
Toxic range where other neurotoxic effects may occur |
Source from Aerias
Concentrations of many VOC are consistently (up to ten times) higher indoors than outdoors (US Environmental Protection Agency, 2010). Therefore, some VOC are regulated due to its short and long term affects on the health of humans. For example, the most common VOC is formaldehyde. On average, formaldehyde levels measured over a day in Canadian homes were 20-40 μg/m3 (16-32.5 ppb). Daily levels as high as 95 μg/m3 (77 ppb), however, have been recorded (Health Canada, 2009b). This chemical is strictly regulated by the Occupational Safety & Health Administration (OSHA) as it has been known to cause cancer. Table 2, below, lists a few common VOC along with the recommended exposure limit (REL) of the National Institute for Occupational Safety and Health (NIOSH), permissible exposure limit (PEL) of OSHA, identified symptoms if exposed to the chemical and some examples of products that contain the chemical.
Table 2: Common VOC
|
Chemical |
Exposure Limit |
Symptoms |
A Few Examples |
|
Acetone C3H6O |
NIOSH REL:
OSHA PEL:
|
eyes/nose/throat irritation, headache, dizziness, central nervous system depression |
Nail polish remover Paint thinners Sanitary cleaner |
|
Arsine AsH3 |
NIOSH REL:
OSHA PEL:
|
headache, malaise, lassitude, dizziness, dyspnea, nausea, vomiting
lung & lymphatic cancer |
Semi-conducting materials Chemical warfare |
|
Benzene C6H6 |
NIOSH REL:
OSHA PEL:TWA 1 ppm ST 5 ppm |
eyes/nose/throat irritation, dizziness, headache, nausea, anorexia, lassitude
leukemia |
Tobacco smoke, Stored fuel Paint supplies Auto emission Laboratory solvent |
|
Formaldehyde CH2O |
NIOSH REL:TWA 0.016 ppm
OSHA PEL:TWA 0.75 ppm ST 2 ppm |
irritation eyes/nose/throat, coughing, wheezing
nasal cancer |
Carpet Pill capsules Disinfectant Preservative in vaccines Pressed wood |
|
Hydrogen Sulfide H2S |
NIOSH REL:10 ppm (15 mg/m3) [10-minute] OSHA PEL:20 ppm - 50 ppm [10-minute maximum peak] |
eyes/nose/throat irritation, apnea, coma, conjunctivitis, photophobia, dizziness, headache, lassitude, irritability, insomnia |
Crude petroleum Natural gas Hot springs Volcanoes |
|
Nitric Oxide NO |
NIOSH REL:TWA 25 ppm (30 mg/m3) OSHA PEL:TWA 25 ppm (30 mg/m3) |
unconsciousness, eye irritation, drowsiness, wet skin/nose/throat |
Tobacco smoke Vehicle exhaust Vaccines |
|
Phosphine PH3 |
NIOSH REL:TWA 0.3 ppm (0.4 mg/m3) ST 1 ppm (1 mg/m3) OSHA PEL:TWA 0.3 ppm (0.4 mg/m3) |
nausea, vomiting, abdominal pain, diarrhea, chest tightness, dyspnea, pulmonary edema |
Clothing Microelectronics Pesticide |
|
Styrene |
NIOSH REL:TWA 50 ppm (215 mg/m3) ST 100 ppm (425 mg/m3) OSHA PEL:TWA 100 ppm C 200 ppm 600 ppm (5-minute maximum peak in any 3 hours) |
eyes/nose irritation, headache, lassitude, dizziness, confusion, malaise, drowsiness, narcosis, reproductive effects |
Synthetic rubber Insulation Fiberglass Pipes Auto and boat parts Food containers Carpet backing |
|
Toluene C7H8 |
NIOSH REL:TWA 100 ppm (375 mg/m3) ST 150 ppm (560 mg/m3) OSHA PEL:TWA 200 ppm C 300 ppm 500 ppm (10-minute maximum peak) |
eyes/nose irritation, lassitude, confusion, euphoria, dizziness, headache, dilated pupils, lacrimation, anxiety, muscle fatigue, insomnia, paresthesia, dermatitis, liver/kidney damage |
Feedstock Paint solvents Gasoline Silicone sealants Printing ink Adhesives Disinfectants |
|
Xylene C6H4C2H6 |
NIOSH REL:TWA 100 ppm (435 mg/m3) ST 150 ppm (655 mg/m3) OSHA PEL:TWA 100 ppm (435 mg/m3) |
eyes/nose/throat/skin irritation, dizziness, excitement, drowsiness, corneal vacuolization, anorexia, nausea, vomiting, abdominal pain, dermatitis |
Plastic bottles Polyester clothing Cleaning agents Paint thinner Paints & varnishes Gasoline Concrete sealers |
TWA = Time Weighted Average
Sick Building Syndrome (SBS) and Building Related Illness (BRI)
Long term exposure to VOC contributes to SBS and BRI. Based on the US Environmental Protection Agency (1991), SBS and BRI are compared in Table 3 below:
Table 3: Comparison between SBS & BRI
|
|
Sick Building Syndrome (SBS) |
Building Related Illness (BRI) |
|
Definition |
An illness temporarily associated with an occupant’s presence in a building caused by indoor air pollutants. |
A diagnosable illness caused by an identified agent in the indoor air. |
|
Symptoms |
Headaches Eye, nose, throat irritation Dry cough Dry or itchy skin Dizziness Nausea Fatigue |
Cough Chest tightness Fever Chills Muscle aches |
|
Cause |
Unknown |
Identified |
|
Symptom after leaving building |
Relief |
Require prolong recovery time |
Photo-ionization Detector (PID)
A PID is commonly used to measure TVOC mainly because it is the most efficient on the market. It provides instant and continuous readings to the user. However, if there’s a rapid temperature change or humidity level is high, the reading maybe affected.
PID is great for indicating the presence of VOC but it doesn’t identify the exact type of VOC. If a TVOC reading is 200 µg/m3 and increased to 300 µg/m3 the next month, it’s impossible to say the increase was due to formaldehyde. It’s also impossible to identify what combination of VOC made up the TVOC reading.
Ideally, measuring the exact type of VOC and monitoring it is a better practice. Unfortunately, this is not the case due to very high cost and convenience. In the short term, having one instrument to provide a TVOC reading as well as other sensors is less expensive and easier for the technician than to have to carry multiple units for each type of chemical. However, in the long term, if a high reading was detected, it will cost more to solve the problem since the type of VOC needs to be identified before a solution gets established. The technician would need to make a lot of assumptions and do a lot of trial and error runs which could take forever or a more simple method would be to analyze the air samples. Depending on the seriousness of the situation, other costs that get lumped into the problem are evacuation of the occupants, specific VOC detector(s) needs to be purchased, delays of other projects, and the time of all the individuals involved.
Common buildings that should monitor their IAQ include:
- Hospitals
- Scientific facilities eg. laboratories
- School
- Commercial buildings
- Warehouses
- Industrial buildings
- Parkades
- Repair shops
- Food plants
- Salons & spas
- Manufacturing Plants
- Medical Offices
- Construction sites
- Transportation facilities
- And many more…
How can you improve the IAQ around you?
Now that you have an understanding about the air that you’re breathing, you can take can control and improve your IAQ. Here are some preventatives that you can do to minimize your health risk:
- If using products that have high fume make sure there is proper ventilation. Outdoor air can dilute the chemical level.
- No smoking indoors or near windows or doors. Tobacco smoke gets absorbed by furniture, carpets, curtains, etc. and takes a long time to be desorbed.
- Chimney needs to be cleaned and clear of obstructions.
- Don’t idle vehicles or gas powered equipment indoor (eg. garage) or near windows or doors.
- For building & household products, use “green” or “environmentally friendly” options.
- If possible, wash and air out products (eg. drapes, clothing, sheets) containing any VOC before bringing indoor.
- Buy limited quantities to avoid having leftovers for storage.
- Safely dispose partially full containers of old or unneeded chemicals.
- Prevent moisture build-up inside and make sure water leaks are cleaned up rapidly.
- Keep humidity levels below 60% (Aerias) by purchasing a dehumidifier. High humidity encourages off gassing.
- Read labels and use as directed.
For suggestions on gas detection systems, indoor air quality monitors and calibration, please visit www.critical-environment.com.
References
Aerias. “VOCs: A Major Contributor to Indoor Pollution”. Retrieved June 8, 2010 from http://www.aerias.org/DesktopModules/ArticleDetail.aspx?articleId=131.
Berglund, et al. (1997). “Total Volatile Organic Compounds (TVOC) in Indoor Air quality Investigations”. Retrieved June 8, 2010 from http://www.inive.org/medias/ECA/ECA_Report19.pdf.
Centers for Disease Control and Prevention. (2010). “NIOSH Pocket Guide to Chemical Hazards”. Retrieved June 8, 2010 from http://www.cdc.gov/niosh/npg/default.html.
Environment Canada. (2010). “Clean Air Online”. Retrieved June 7, 2010 from http://www.ec.gc.ca/cleanair-airpur/Home-WS8C3F7D55-1_En.htm.
Gilbert, Nicolas. (2005). “Proposed residential indoor air quality guidelines for formaldehyde”. Retrieved June 3, 2010 from http://www.hc-sc.gc.ca/ewh-semt/alt_formats/hecs-sesc/pdf/pubs/air/formaldehyde/in-formaldehyde-eng.pdf.
Health Canada. (2006). “Residential Indoor Air Quality Guideline: Formaldehyde”. Retrieved June 4, 2010 from http://www.hc-sc.gc.ca/ewh-semt/alt_formats/hecs-sesc/pdf/pubs/air/formaldehyde-eng.pdf.
Health Canada. (2009a). “Formaldehyde - Pollutants from Household Products and Building Materials”. Retrieved June 3, 2010 from http://www.hc-sc.gc.ca/ewh-semt/air/in/poll/construction/formaldehyde-eng.php.
Health Canada. (2009b). “It's Your Health: Formaldehyde and Indoor Air”. Retrieved June 4, 2010 from http://www.hc-sc.gc.ca/hl-vs/alt_formats/pacrb-dgapcr/pdf/iyh-vsv/environ/formaldehyde-eng.pdf.
US Environmental Protection Agency. (1991). “Indoor Air Fact Sheet No. 4 (revised) – Sick Building Syndrome”. Retrieved June 8, 2010 from http://www.epa.gov/iaq/pubs/sbs.html.
US Environmental Protection Agency. (1994). “Indoor Air Pollution: An Introduction for Health Professionals”. Retrieved June 8, 2010 from http://www.epa.gov/iaq/pubs/hpguide.html.
US Environmental Protection Agency. (2010). “An Introduction to Indoor Air Quality: Volatile Organic Compounds (VOCs)”. Retrieved June 8, 2010 from http://www.epa.gov/iaq/voc.html.
World Health Organization. (1989). “International Programme on Chemical Safety (IPCS): Environmental Health Criteria 89: Formaldehyde”. Retrieved June 2, 2010 from http://www.inchem.org/documents/ehc/ehc/ehc89.htm.