Illness from chemical "odors": is the health significance understood?

Italian Expert Consensus on Clinical and Therapeutic Management of Multiple Chemical Sensitivity (MCS)

Multiple chemical sensitivity (MCS) is a multisystem, recurrent, environmental disorder that flares in response to different exposures (i.e., pesticides, solvents, toxic metals and molds) under the threshold limit value (TLV) calculated for age and gender in the general population. MCS is a syndrome characterized by cutaneous, allergic, gastrointestinal, rheumatological, endocrinological, cardiological and neurological signs and symptoms. We performed a systematic review of the literature to summarize the current clinical and therapeutic evidence and then oriented an eDelphi consensus. Four main research domains were identified (diagnosis, treatment, hospitalization and emergency) and discussed by 10 experts and an MCS patient. Thus, the first Italian MCS consensus had the double aim: (a) to improve MCS knowledge among healthcare workers and patients by standardizing the clinical and therapeutic management to MCS patients; and (b) to improve and shed light on MCS misconceptions not supported by evidence-based medicine (EBM).

Workers' Fight for Justice: A Retrospective Exposure Profile Study of the GE Factory in Peterborough, Ontario

Occupational disease recognition is often hampered by lack of historical exposure data. This paper describes research documenting major chemical exposures of Canadian General Electric workers in a plant in Peterborough between 1945 and 2000. Workers’ experiences with diseases over forty years, and their frustration with the continual denial that these were work-related, drove this study. Researchers used qualitative methods, participatory action research, hazard mapping, and risk assessment. A report that incorporates this study’s findings documents extremely toxic exposures that placed Canadian General Electric workers at a disproportionate risk of occupational diseases. Since the report’s release, the Ontario Workplace Safety and Insurance Board reconsidered 233 previously denied claims in the light of “new evidence” and overturned one half of those it reviewed. The retrospective exposure profile methods used in this study may serve as a useful model for workers and their organization when plants close.

Multiple Chemical Sensitivity, Culture and Delegitimization: A Feminist Analysis

The condition referred to as multiple chemical sensitivity (MCS), chemical injury (CI), environmental illness (El), 20th-century disease or toxic encephalopathy has generated controversy because victims' claims of harm from low levels of chemicals in the environment conflict with general mainstream belief in the safety of these substances. Mainstream (western) culture's response to persons with MCSICI has interacted with sexism, served to delegitimize victims thereby reducing their power, reduced the victim's context (because of forced isolation), and jeopardized jobs and relationships. This article will analyze the situation of the chemically injured person and culture's response from a feminist perspective, and discuss cultural delegitimization as a process used by a chemical culture to neutralize the message of the person with MCSICI, i.e., that the environment is unsafe for her/him, and, by extension, for others.

(M)VOC and composting facilities. Part 2: (M)VOC dispersal in the environment

BACKGROUND, AIMS AND SCOPE

Composting facilities are known to release odorous volatiles due to biodegradation of municipal waste and plant residues. Although odour perception and its grading is influenced by experience, attitude and adaptation, these emissions have created a lack of acceptance for residents in the vicinity of composting facilities. Enclosure of compost pile halls, ventilation systems and biofilters are often insufficient to minimise the burden of compost-derived compounds in the air. Moreover, economic considerations forced smaller communities to establish less sophisticated facilities with open storage areas and other relevant sources for wind-borne dispersal of bioaerosols. Aim of the present study was to characterise the immission and dispersal of microbial volatiles (MVOC) and, besides, to find coincidences between MVOC and compost odour.

METHODS

In the course of this study, the surroundings of two composting facilities, differing in their type of process engineering, were investigated for emission of volatiles in the environment. Both microbially and plant-derived substances were assessed, several of which have low odour thresholds. Air samples were taken in distances ranging from 50 to 800 m in a downwind direction from each facility.

RESULTS AND DISCUSSION

Compost-derived and microbial volatile organic compounds (MVOC) were found at distances of up to 800 m from the composting facilities. Terpenes like alpha-pinene, camphene and camphor were the dominant compounds and coincided with typical compost odour, whereas several typical MVOC were not found at greater distances. The terpenes in combination with certain MVOC may play an important role in the perception of compost odour. Exposure concentrations were not of toxicological relevance, but sensory irritation and psychohygienic effects due to an annoyance potential of such compounds should not be dismissed.

RECOMMENDATIONS AND OUTLOOK

Although terpenes are generally associated with pleasant odour characteristics, they seemed to contribute to malodours in a mixture with other VOC, in this context of volatile waste from compost facilities. Malodorous emissions from biowaste have to be considered as sources of health complaints and the investigation of mixtures of compost-derived volatiles is still inevitable. Exposure levels have to be discussed taking VOC mixtures into account. Within composting facilities, technical devices have to be improved to minimise dispersal of volatiles to prevent residents from immissions eventually causing health complaints.

Idiopathic Environmental Intolerance

Toxicogenic and psychogenic theories have been proposed to explain idiopathic environmental intolerance (IEI). Part 2 of this article is an evidence-based causality analysis of the psychogenic theory using an extended version of Bradford Hill's criteria. The psychogenic theory meets all of the criteria directly or indirectly and is characterised by a progressive research programme including double-blind, placebo-controlled provocation challenge studies. We conclude that IEI is a belief characterised by an overvalued idea of toxic attribution of symptoms and disability, fulfilling criteria for a somatoform disorder and a functional somatic syndrome. A neurobiological diathesis similar to anxiety, specifically panic disorder, is a neurobiologically plausible mechanism to explain triggered reactions to ambient doses of environmental agents, real or perceived. In addition, there is a cognitively mediated fear response mechanism characterised by vigilance for perceived exposures and bodily sensations that are subsequently amplified in the process of learned sensitivity. Implications for the assessment and treatment of patients are presented.

Mechanisms of multiple chemical sensitivity

Sensitivity to chemicals is a toxicological concept, contained in the dose-response relationship. Sensitivity also includes the concept of hypersensitivity, although controversy surrounds the nature of effects from very low exposures. The term multiple chemical sensitivity has been used to describe individuals with a debilitating, multi-organ sensitivity following chemical exposures. Many aspects of this condition extend the nature of sensitivity to low levels of exposure to chemicals, and is a designation with medical, immunological, neuropsychological and toxicological perspectives. The basis of MCS is still to be identified, although a large number of hypersensitivity, immunological, psychological, neurological and toxicological mechanisms have been suggested, including: allergy; autosuggestion; cacosomia; conditioned response; immunological; impairment of biochemical pathways involved in energy production; impairment of neurochemical pathways; illness belief system; limbic kindling; olfactory threshold sensitivity; panic disorder; psychosomatic condition; malingering; neurogenic inflammation; overload of biotransformation pathways (also linked with free radical production); psychological or psychiatric illness; airway reactivity; sensitisation of the neurological system; time dependent sensitisation, toxicant induced loss of tolerance. Most of these theories tend to break down into concepts involving: (1) disruption in immunological/allergy processes; (2) alteration in nervous system function; (3) changes in biochemical or biotransformation capacity; (4) changes in psychological/neurobehavioural function. Research into the possible mechanisms of MCS is far from complete. However, a number of promising avenues of investigation indicate that the possibility of alteration of the sensitivity of nervous system cells (neurogenic inflammation, limbic kindling, cacosomia, neurogenic switching) are a possible mechanism for MCS.

Acquisition and extinction of somatic symptoms in response to odours: a Pavlovian paradigm relevant to multiple chemical sensitivity

OBJECTIVES

Multiple chemical sensitivity is a poorly understood syndrome in which various symptoms are triggered by chemically unrelated, but often odorous substances, at doses below those known to be harmful. This study focuses on the process of pavlovian acquisition and extinction of somatic symptoms triggered by odours.

METHODS

Diluted ammonia and butyric acid were odorous conditioned stimuli (CS). The unconditioned stimulus (US) was 7.4% CO2 enriched air. One odour (CS+) was presented together with the US for 2 minutes (CS+ trial), and the other odour (CS-) was presented with air (CS-trial). Three CS+ and three CS-exposures were run in a semi-randomised order; this as the acquisition (conditioning) phase. To test the effect of the conditioning, each subject then had one CS+ only--that is, CS+ without CO2--and one CS- test exposure. Next, half the subjects (n = 32) received five additional CS+ only exposures (extinction group), while the other half received five exposures to breathing air (wait group). Finally, all subjects got one CS+ only test exposure to test the effect of the extinction. Ventilatory responses were measured during and somatic symptoms after each exposure.

RESULTS

More symptoms were reported upon exposure to CS+ only than to CS-odours, regardless of the odour type. Altered respiratory rate was only found when ammonia was CS+. Five extinction trials were sufficient to reduce the level of acquired symptoms.

CONCLUSION

Subjects can acquire somatic symptoms and altered respiratory behaviour in response to harmless, but odorous chemical substances, if these odours have been associated with a physiological challenge that originally had caused these symptoms. The conditioned symptoms can subsequently be reduced in an extinction procedure. The study further supports the plausibility of a pavlovian conditioning hypothesis to explain the pathogenesis of MCS.

Clinical and immunological responses in subjects sensitive to solvents

Twenty patients proved sensitive to a 15-min exposure to 15 ppm toluene. We assessed patients neuropsychologically before and after toluene exposure, and they had impaired cognitive functioning characterized by a deterioration in short- and long-term memory and psychomotor coordination. We measured total immunoglobin G and T-cell antigen-binding molecules against an antigen prepared by conjugation of para-aminobenzoic acid to human serum albumin in 20 patients and 16 controls. There was no significant difference in the immunoglobulin G levels to the antigen in the 2 groups, but the levels of T-cell antigen-binding molecules against the para-aminobenzoic acid conjugated to human serum albumin were elevated significantly in subjects sensitive to toluene. We also found significant associations between T-cell antigen-binding molecule levels and (a) decreased performance on the STROOP (Colour Word) test, (b) a shift in focal length following toluene exposure, (c) clinical assessment of disability, and (d) longer histories of chemical exposure. The measurement of T-cell antigen-binding molecules against chemical haptens may be valuable in the assessment of patients who are sensitive to chemicals.

Multiple chemical sensitivities: the social construction of an illness

Multiple chemical sensitivities (MCS) has emerged as an important and highly controversial issue in occupational health. Debate centers on whether the illness is "physical" or "psychological." A strong corporate-backed campaign has framed the debate and has pushed MCS advocates into a strategy of "proving the physical" nature of MCS. Proponents of both positions, however, share key assumptions that impede long-term efforts to benefit MCS sufferers, including acceptance of the physical/psychological dichotomy as a paradigm for the illness, a desire to rid the debate of "politics" to allow "objective scientific" data to be amassed, and a view of MCS as unique without links to other occupational illnesses. While a grassroots movement has benefited MCS sufferers in a number of important ways, the shared assumptions have impeded development of a more complex model for the illness that is reflective of a complex reality, reproduced mainstream expert/non-expert relationships, and failed to connect with the broader occupational health and safety movement. The author outlines an alternative theory and practice to begin addressing these issues, beginning with a recognition of MCS as a problem of developing knowledge within a context of class power.

Environmental health response clinics. A survey of program options

Environmental Health Response Clinics are established in response to concerns about community exposures to hazardous situations (chemical, biological, radiological). They are developed in response to a demand for "clinical services" and operate outside the usual health care financing and delivery mechanisms. Prompted by their experience in California, the authors formed a focus group to identify possible goals and services. A mail survey of occupational-environmental health professionals was then conducted to evaluate the feasibility and priority of representative goals. The analysis suggests that services should focus on the specific hazard of concern and that communication and education are essential components. The tendency to "do a general physical examination" should be eschewed. Ratings for priority and feasibility were disparate for several possible goals. In some instances, a "hands-on examination" may not be the best use of resources. Environmental health professionals may serve by direct clinical service or by advising community-based practitioners. Providing routine clinical services alone cannot meet the expectations for an environmental health response clinic.

Multiple chemical sensitivity (MCS) : Idiopathic environmental intolerances (IEI)

Multiple Chemical Sensitivity (MCS) is a systemic disorder causing central nervous, irritative and gastrointestinal symptoms, and can be included in the category of "idiopathic environmental intolerance" (IEI). This term describes phenomena with multiple, recurrent symptoms associated with various environmental factors that are tolerated by most people without problems. Those advocating these concepts attribute the symptoms to exogenous substances. Those opposing them explain the phenomena by classical conditioning or other psychopathological processes. To the extent that controlled studies are available, they have not furnished any hard evidence for toxic or immunological causes. In addition to psychopathological origins, neurobiological processes are also implicated.

Psychiatric Aspects of Air Pollution

Psychological and toxic effects of air pollution can lead to psychiatric symptoms, including anxiety and changes in mood, cognition, and behavior. Increased levels of some air pollutants are accompanied by an increase in psychiatric admissions and emergency calls and, in some studies, by changes in behavior and a reduction in psychological well-being. Numerous toxic pollutants interfere with the development and adult functioning of the nervous system. Manifestations are often insidious or delayed, but they can provide a more sensitive indicator of toxic effects than cancer rates or mortality data. Other medical effects of air pollution, such as asthma, can indirectly affect psychological health. The sick building syndrome and multiple chemical sensitivity are conditions with toxicologic and psychiatric aspects. Psychosocial stress can cause symptoms similar to those of organic mental disorders. Reactions to stress depend on cultural, individual, and situational variables. We must understand these factors to be able to alleviate and prevent the consequences of environmental trauma. Expanded research is recommended in three main areas: (1) how people perceive and cope with environmental health risks, (2) the effects of air pollution on behavior and neuropsychological functioning, and (3) neurotoxicologic evaluation of air pollutants with both behavioral and in Vitro Studies.

Respiratory learning and somatic complaints: a conditioning approach using CO2-enriched air inhalation

In a differential respiratory conditioning paradigm with normal Ss two odors (fresh smelling niaouli and bad smelling ammonia) were used as conditioned stimuli (CS+ or CS-) and 7.4% CO2-enriched air was used as the unconditioned stimulus (US). Three CS+ and three CS- trials were run during acquisition, followed on the next day by the same number of CS+ and CS- only trials. Respiratory frequency, minute ventilation, end-tidal fractional concentration of CO2 and subjective complaints were measured throughout the experiment. While during acquisition all measures were affected, the conditioning effects included only respiratory frequency and subjective complaints. A selective association effect appeared in that the conditioning effects were confined to ammonia as CS+: respiratory frequency increased and more somatic complaints were presented when compared to the CS- condition. The conditioning effect on complaints was not confined to complaints of general arousal, but included respiratory complaints as well. Correlational analyses showed that increases in complaints as caused by the conditioning procedure were predicted by changes in somatic variables, but not by individual differences in Negative Affectivity.