Environmental Project, 988 – Multiple Chemical Sensitivity, MCS

The following is a short resumé of the methods used the most for diagnosing MCS in the US today. They have to do with finding and using biomarkers for exposure, effects and incidence. Biomarkers are among the most important tools for investigating the impacts of environmental factors on health. They can indicate changes in biological systems and/or environmental illnesses such as MCS.

Biomarkers for exposure indicate that a certain exposure has taken place. The chemicals, which the body has absorbed, or derivatives thereof in blood serum, urine or tissue samples, are measured. E.g., analytical methods have been devised to detect biomarkers in connection with exposure to heavy metals and a large number of organic chemicals such as formaldehyde, aromatic hydrocarbons, pesticides, dioxins, and PCBs and for complex exposures to, e.g., tobacco smoke.

Biomarkers for effect indicate quantitative and qualitative changes in the functioning of organs or the health of exposed persons, e.g., changes in lung function, genotoxic effects on extracted tissue samples, propagation or extrusion of inflammatory cells, or signal substances in tissue samples or urine and/or blood samples.

Provocation tests in special provocation chambers, so-called climate chambers, are MCS-specific. The climate chamber was developed by environmental and other physicians to investigate and treat MCS patients and for indoor climate research. The high technical and scientific standards^[4], which are set for the construction, maintenance and running of climate chambers, make climate chambers very expensive (Selner, 1996). In the US, three well-known research centres use climate chambers for MCS and GWS research.

In Denmark climate chambers are found at the Danish Technical University, at the National Institute of Occupational Health, and at the Institute of Occupational and Environmental Medicine at the University of Aarhus. These climate chambers are only used for indoor climate research and not for examining or treating MCS patients.

At the Department of Oto-rhino-laryngology at the National Hospital of DenmarkCopenhagen University Hospital (Risgshospitalet) the physicians have performed “open” provocation experiments with xylene. The reaction in the vestibular organ (Vestibular autorotation test, VAT) and other physiological parameters (blood pressure and pulse) are measured before, during, and after provocation. The test was developed as a tool for screening for MCS. Normal values are based on values from a reference group. Provisional results show agreement between positive VAT and MCS in 80% of the cases. The method has not been fully standardised and should be developed further. Provisional results have been presented at a conference (Holmelund, 1993).

7.2 Diagnosing MCS

As long as MCS has not been recognised as a disease using scientific medical criteria, the condition cannot be registered in the International Classification of Diseases version 10 (ICD-10) of the WHO. It is, therefore, not included in the Danish medical statistics.

In the US an initiative group consisting of 34 physicians and researches from several fields, who have dealt with MCS problems for many years, have put forward a proposal for how to get out of the logjam concerning MCS diagnostics in the US (Consensus, 1999).

The clinical definition includes six items of which five have been approved by 89 clinicians and researchers (36 allergologists, 23 occupational physicians, 20 clinical ecologists, 10 specialists in internal medicine and oto-rhino-laryngology respectively (Nethercott, 1993). The initiative group proposed the sixth item.

The symptoms can be reproduced by repeated chemical exposure.
The condition is chronic.
Low concentrations (lower than previously tolerated by the patient) produce health complaints.
The health complaints improve or disappear when the source of exposure is removed.
Various non-related chemicals produce health complaints.
Symptoms of illness pertain to several organs (added in 1999).

The group proposed that the MCS diagnosis is certain when all six criteria are met, even when other illnesses (such as asthma, migraine, chronic fatigue syndrome, etc.) are present.

The group also puts forward concrete proposals for a clinical protocol and for a research protocol. The proposal contains a possibility for combining research into several illnesses.

Approved screening questionnaire
List of alternative illnesses for differential diagnosis
List of clinical signs and abnormal values from clinical-chemical parameters (published in peer reviewed literature) even though they are not commonly accepted as biomarkers for MCS
Following up of all MCS cases using qualitative and quantitative methods

MCS criteria for choosing the patient group (inclusion – exclusion criteria shown)
Full description of the examined patient groups (those ill and controls)
Registration and reporting of overlaps with other environmental illnesses

Ashford and Miller (2002) published a standard form with ten questions on health complaints, chemical intolerance, changed living conditions due to symptoms, etc. to register environmental load and chemical sensitivity.

Kutsogiannis and Davidoff (2000) developed a simple biometric questionnaire to register MCS-related issues within six areas, such as symptoms, type and duration, exposure, sensitivity to odours and to other factors, etc., easily. This method could be suited for registering Danish conditions. By relatively simple means, it would be possible to confirm or refute, whether among those previously exposed to solvents some persons with typical MCS symptoms can be found.

7.3 Comments and conclusion

Several methods to confirm or refute the MCS diagnosis have been proposed (e.g., bioimmunoassays, electronic registration of brain functions, questionnaire survey), but none have as yet proven satisfactory.

The Danish health-care system includes no guidelines neither for examination nor for diagnosis of MCS. This chapter contains some proposals as inspiration for future investigations in Denmark.

It is important that Denmark acquires better knowledge of MCS and is able to keep up to date concerning developments in environmental illnesses and MCS.

Firstly, Danish criteria defining the illness, and possibly ways in which to register the illness, should be worked out.

[4]. A climate chamber must be constructed of non-synthetic materials in order to eliminate degassing. A climate chamber must have over pressure and fresh-air ventilation with filters. The furniture is made of natural, not synthetic materials. The personnel must use non-dry-cleaned clothes and neither perfumes nor scented cosmetics.

7 Methods of examination and diagnosis

7.1 Methods of examination

7.2 Diagnosing MCS

7.3 Comments and conclusion