Why Air Quality Testing for VOCs Usually Isn't Helpful for People with MCS

Steve Temes
Industrial Hygienist

Worker health and safety regulations require that workplace contaminant exposure limits not be exceeded. Industrial Hygienists and Indoor Environmental Professionals are trained to conduct air sampling for risk assessment and compliance purposes. The concentrations of airborne contaminants measured using standardized sample collection and analytical methods are compared with established occupational exposure levels (OELs). Based primarily upon toxicological testing, numerical values for these OELs are set to prevent adverse health effects in a hypothetical healthy adult working 40 hours per week. These acceptable exposure values are for general compliance/safety purposes and are not a determinant of "safe" or "unsafe" for an individual who is not "healthy" or "normal" with regard to their individual response to a chemical exposure. There should be no presumption that someone who is not the hypothetical healthy adult worker cannot be affected at levels well below any general exposure guideline. In fact, the American Conference of Governmental Industrial Hygienists (ACGIH), which establishes Threshold Limit Values (TLVs) for use by Industrial Hygienists, explicitly states: "These values are intended for use in the practice of industrial hygiene as guidelines or recommendations to assist in the control of potential workplace health hazards and for no other use. These values are not fine lines between safe and dangerous concentrations and should not be used by anyone untrained in the discipline of industrial hygiene." (http://www.acgih.org/Products/tlvintro.htm).

Some residential exposure guidelines have been established (http://www.epa.gov/risk/expobox/populations/re-overview.htm). These guidelines take into account longer exposure periods and purport to consider susceptible populations. The definition of "susceptible population" does not, however, include individuals with multiple chemical sensitivity (MCS).

For the person who is hypersensitive, a "safe level" of exposure to his or her allergic or chemical trigger(s) means safe for that particular person and not someone else, rendering general exposure guidelines meaningless for that individual. There is no safe level of airborne peanut dust established for children who have a hypersensitivity to peanut allergen because it is widely recognized that some individuals can react severely when exposed to only trace concentrations. The same is true for individuals who react to low levels of common environmental volatile organic compounds (VOCs) such as those in perfumes, air fresheners, laundry or personal care products, or other consumer products containing fragrance chemicals. Individuals can react at extremely low levels of exposure to these VOCs once they have become sensitized. Other common indoor VOCs include emissions from building materials and furnishings, furnaces, gas stoves, and stored items such as household chemicals, heating fuels, or gasoline. Toxicity data regarding the particular volatile chemical compound is not relevant in assessing the sensitized individual's potential to react.

One common scenario in which professionals use testing to declare an environment "safe" is immediately after a mold remediation procedure. The environmental professional will typically perform a post-remediation verification (PRV) inspection for visible mold and dust to assess the quality of the remediation contractor's work and then perform some type of mold testing to assess the presence of any remaining microscopic mold contamination. Mold testing can determine the presence of invisible spores and other particulate contaminants. Mold testing does not, however, detect the presence of microbial volatile organic compounds, or MVOCs, which are the chemicals that constitute the musty, moldy, mildew odors characteristic of microbial growth in water-damaged buildings and damp basements and crawl spaces. Many people with chemical hypersensitivities are reactive to these MVOCs, which continue to desorb (offgas) from surfaces post-remediation. Wiping or vacuuming porous surfaces will not eliminate mold odors. A person with MCS may enter a home or workplace that has been remediated of mold and declared "safe" by an environmental professional based upon mold testing, yet still have a severe reaction to low levels of residual MVOCs.

The only reliable instrument of detection for determining if an environment is safe for someone with MCS is the person who has the chemical sensitivity. Many people have an instantaneous neurologic response to an environmental chemical exposure. They sense immediately when they are in an environment that will be problematic for them. Such immediate symptoms might include a burning sensation in the nasal passages, eyes, lips, or tongue. A sneeze, irritant cough, choke reflex, wheeze, chest tightness, or other respiratory symptom may also be an immediate reaction. Some may instantly feel nauseous or dizzy. Neurogenic inflammatory symptoms such as neurocognitive effects (concentration or memory problems), muscle aches/pains, joint pains, migraine headache, irritable bowel symptoms, abdominal bloating, or personality/mood changes may take a longer time to develop after exposure. Depending upon the individual, it can take seconds, minutes, hours, or even days for chemical hypersensitivity symptoms to fully manifest.

A professional cannot test the air to determine which low-level chemical contaminant caused a hypersensitivity reaction to occur in a given individual. You cannot prove the negative by testing to determine that an environment did not cause an individual chemical hypersensitivity reaction. Many attorneys believe that environmental testing for VOCs will prove that there is, or is not, an indoor air quality cause of chemical hypersensitivity symptoms. Often, the levels of indoor volatile chemical species in the laboratory analytical report are not deemed by knowledgeable professionals to be harmful at the concentrations present. What starts out as an attempt to demonstrate with testing that an environment is causing symptoms often proves, based upon ATSDR toxicity data, that the chemical exposures are not considered harmful. A litigation strategy based upon testing may backfire on a plaintiff when the lab results are used by the defendant to argue that the level of contaminant exposure is too low to be causing symptoms in the person who is claiming to react in that environment.

In conclusion, testing to determine airborne chemical exposure levels is only useful when one's goal is to compare these values with health and safety guidelines that have been established based upon known health risk. These exposure guidelines do not take into account, however, the potential for various chemical compounds to trigger an individual hypersensitivity reaction and cannot be used to determine the acceptability of an environment for a sensitized person.