The average person spends over 90% of their time indoors. We are constantly being bombarded with indoor air pollution. This includes toxic fumes such as formaldehyde, VOCs, trichloroethylene, carbon monoxide, benzene, toluene, xylene, and countless others.

Formaldehyde (CH2O)

Formaldehyde is an organic chemical that is very prevalent in our environment. It has colorless gas with a pungent odor from a family of gases called aldehydes. Commonly known as a preservative in medical laboratories and mortuaries, formaldehyde is also found in other productssuch as furniture, wall paper, cardboard, and facial tissues. It is also used in some plastics, paints, varnishes, dishwashing liquids, fabric softeners, and cosmetics, such as nail polish. It enters the indoor environment through natural sources such as forest fires and certain human activities, including burning tobacco, gasoline and wood. As a result of being in so many common products and so prevalent in the environment, it is present, in its breathable gas form, in virtually all homes and buildings. Studies have suggested that people who are exposed to low levels of formaldehyde for long periods of time are more likely to experience asthma-related respiratory symptoms, such as coughing and wheezing. In higher amounts formaldehyde is known to cause cancer of the nasal cavity.

The World Health Organization guideline for indoor air formaldehyde concentration is 0.08 ppm (0.1mg/m3).

Formaldehyde is normally present at low levels, usually less than 0.03 ppm in both outdoor and indoor air. The out door air in rural area ha lower concentrations while urban areas have higher concentrations. Residences or offices that contain products that release formaldehyde to the air can have formaldehyde levels of greater than 0.03 ppm

There are numerous methods for determining the concentration of formaldehyde in indoor air. Air testing for formaldehyde can be conducted using either passive or active sampling techniques. only trained professionals should measure formaldehyde because of the difficulty of obtaining good data and interpreting the results.

Trichloroethylene (TCE)

is a common indoor pollutant being released from paints, dry cleaning, adhesives, pesticides and the ink in copy machines, faxes, and printers. Short-term exposure to TCE causes irritation of the nose and throat and depression of the central nervous system. Higher concentrations have caused numbness and facial pain, reduced eyesight, unconsciousness, irregular heartbeat and even death.

Carbon monoxide (CO)

is a dangerous gas which is produced from open fires, gas stoves, appliances and heaters. It is also present in high concentrations in cigarette smoke and vehicle exhaust. Low level exposure causes dizziness and headaches while more acute exposure can lead to death because CO actually prevents the delivery of oxygen to the body's cells.

Benzene (C6H6), Toluene (C7H8) and Xylene (C8H10)

are found in the vapour of products such as gasoline, oils, paints, glues, inks, plastics, and rubber, where they are used as solvents.


Phthalates are a class of widely used industrial compounds known technically as dialkyl or alkyl aryl esters of 1,2-benzenedicarboxylic or volatile organic compounds are found in all petroleum products; however there are many other sources such as flooring adhesives (used for carpeting, hardwoods, etc), paint, furniture, wall materials, electronic equipment, cigarette smoke, household cleaning products and even air fresheners!

Intentional uses of phthalates include softeners of plastics, oily substances in perfumes, additives to hairsprays, lubricants and wood finishers. That new car smell, which becomes especially pungent after the car has been sitting in the sun for a few hours, is partly the pungent odor of phthalates volatilizing from a hot plastic dashboard. In the evening's cool they then condense out of the inside air of the car to form an oily coating on the inside of the windshield

Health effects

Health concerns related to phthalate ester exposures have focused primarily on cancer and reproductive effects (Kavlock et al. 2002a, 2002b, 2002c; NTP 2003). However, phthalate exposures have also been postulated to have a role in the pathogenesis of asthma (Oie et al. 1997), and plasticized indoor materials have been associated with the development of bronchial obstruction in young children (Jaakkola et al. 1999). We recently reported an association between asthma and allergies in children and phthalate concentrations in dust collected from the children’s bedrooms (Bornehag et al. 2004b). The geometric mean concentrations of BBzP were higher in dust from rooms of children with rhinitis compared with controls (0.237 vs. 0.157 mg/g dust, p = 0.001) and of children with eczema compared with controls.

The main finding from this study is that the concentrations of BBzP and DEHP in dust are associated with the amount of PVC/vinyl used as flooring and wall material in the home, but that there are also many other sources of these phthalates. Although PVC flooring and vinyl on walls do not fully explain the concentration of phthalates in dust, occurrences of such materials are associated with higher concentrations of DEHP and BBzP in dust indoors. There are also associations between the concentration of BBzP in bedroom dust and water leakage in the previous 3 years

HEAVY METALS: Airborne Lead and Mercury Vapor

Airborne Lead


Indoors, the chief source is paint. Lead levels in paints for interior use have been increasingly restricted since the 1950's, and are now virtually lead free. But many older houses may still have coat after coat of leaded paint covered with peeling non-lead paint. In these circumstances, lead dust and fumes can permeate the air and affect both adults and children.

Products made of PVC, which often contain lead,  such as toys, teethers, and lunchboxes. Old toys and furniture made prior to 1978 may also contain lead-based paint

Health effects

Decades of evidence on lead’s health effects were amassed before the metal was banned in paint and gasoline, and lead is still allowed in many consumer products.

Common Health effects: behavioral problems,high blood pressure, anemia,kidney damage, memory and learning difficulties
miscarriage, decreased sperm production
, reduced IQ

Methods of measurement

When testing for lead paint, all interior rooms, the exterior sides, and the outside property around the unit should be inspected.

XRF: the recommended method for testing a unit is the high-energy K-Shell readings from a portable x-ray Fluorescence (XRF). XRF results are in units of milligrams per square centimeter. An average of three readings is recommended. Each reading should be approximately 15 seconds with a new source.
Paint sampling: Paint samples may be collected and sent to a laboratory for analysis. Paint samples should be collected from a one square inch area.

Mercury Vapor


Mercury use in products such as thermometers and thermostats, but major sources like coal burning continue.

A 1990 report detailed elevated levels of mercury in persons exposed to interior latex (water-based) paint containing phenylmercuric acetate (PMA). PMA was a preservative that was use to prolong the product's shelf life.

The EPA eliminated the use of mercury compounds form indoor index paints at the point of manufacture as of August 1990, with the requirement that paints containing mercury, including existing stock to be labeled for external use only. Then in September 1991 PMA was no longer allowed in exterior paint either. However, latex paint containing hazardous levels of mercury may still be on the store shelves or in homes where they were left over.

Health effects

Common Health effects : blindness and deafness, brain damage, digestive problems, kidney damage, lack of coordination, mental retardation

Methods of measurement

Detector Tubes: This is a relatively simple method for determining gas concentrations. They are usually calibrated in ppm for easy interpretation. There are different tubes to detect different gases, in this case it would be mercury vapor. Pumps are used for drawing are through the tube. Each tube requires a set volume of gas to be drawn through the pump in order to insure detection if present. Any change in color with in the tube is a detection of mercury. The length of the color streak is an indication of concentration.


Mercury vapor along with liquid mercury is harmful if not regulated and should be taken care of by a professional if levels are above what is recommended by environmental safety specialists.