Multiple Chemical Sensitivity Research Articles

In-situ Real-Time Monitoring of Volatile Organic Compound Exposure and Heart Rate Variability for Patients with Multiple Chemical Sensitivity.

In-situ real-time monitoring of volatile organic compound (VOC) exposure and heart rate variability (HRV) were conducted for eight multiple chemical sensitivity (MCS) patients using a VOC monitor, a Holter monitor, and a time-activity questionnaire for 24 h to identify the relationship between VOC exposure, biological effects, and subjective symptoms in actual life. The results revealed no significantly different parameters for averaged values such as VOC concentration, HF (high frequency), and LF (low frequency) to HF ratio compared with previous data from healthy subjects (Int. J. Environ. Res. Public Health 2010, 7, 4127–4138). Significant negative correlations for four subjects were observed between HF and amounts of VOC change. These results suggest that some patients show inhibition of parasympathetic activities along with VOC exposure as observed in healthy subjects. Comparing the parameters during subjective symptoms and normal condition, VOC concentration and/or VOC change were high except for one subject. HF values were low for five subjects during subjective symptoms. Examining the time-series data for VOC exposure and HF of each subject showed that the subjective symptoms, VOC exposure, and HF seemed well related in some symptoms. Based on these characteristics, prevention measures of symptoms for each subject may be proposed.

Multiple chemical sensitivity

Multiple chemical sensitivity

Does electromagnetic hypersensitivity originate from nocebo responses? Indications from a qualitative study

Idiopathic Environmental Intolerance attributed to Electromagnetic Fields (IEI-EMF) is a condition in which symptoms are attributed to electromagnetic field (EMF) exposure. As electro-hypersensitive (EHS) people have repeatedly been observed, during provocation trials, to report symptoms following perceived rather than actual exposure, the hypothesis has been put forward that IEI-EMF originates from psychological mechanisms, especially nocebo responses. This paper examines this hypothesis, using data from a qualitative study aimed at understanding how EHS people come to regard themselves as such. Forty self-diagnosed EHS people were interviewed. A typified model of their attribution process was then elaborated, inductively, from their narratives. This model is linear and composed of seven stages: (1) onset of symptoms; (2) failure to find a solution; (3) discovery of EHS; (4) gathering of information about EHS; (5) implicit appearance of conviction; (6) experimentation; (7) conscious acceptance of conviction. Overall, symptoms appear before subjects start questioning effects of EMF on their health, which is not consistent with the hypothesis that IEI-EMF originates from nocebo responses to perceived EMF exposure. However, such responses might occur at the sixth stage of the process, potentially reinforcing the attribution. It remains possible that some cases of IEI-EMF originate from other psychological mechanisms.

Mindfulness-based cognitive therapy (MBCT) for multiple chemical sensitivity (MCS): Results from a randomized controlled trial with 1 year follow-up

ObjectiveMultiple chemical sensitivity (MCS) is a medically unexplained condition characterized by symptoms from multiple organ systems following the perception of common odorants. The condition can cause severe functional impairment for afflicted individuals. The aim of this study was to assess the effects of mindfulness-based cognitive therapy (MBCT) for individuals with MCS. MethodsThe intention-to-treat sample (ITT) included 69 individuals who had been randomized to either MBCT or treatment as usual (TAU). The primary outcome measure was the Quick Environmental Exposure and Sensitivity Inventory (QEESI), which measures the following aspects of MCS: impact of MCS on daily life, symptoms, and reactions following chemical exposures. Secondary outcome measures included the Brief Illness Perception Questionnaire (BIPQ) and the anxiety and depression subscales of the symptom checklist 92 (SCL-92). Participants were assessed at baseline and post treatment, and at follow-up periods of 6- and 12-months. ResultsWe found no effect of MBCT on the primary outcome, nor did we find an effect on levels of depression or anxiety. We did, however, find positive changes in illness perceptions, which were sustained at 12-month follow-up. Dropout rates were low, suggesting MBCT was well received and regarded as an acceptable intervention by individuals with MCS. ConclusionsOverall, these results suggest that MBCT does not change overall illness status in individuals with MCS, but that MBCT positively changes emotional and cognitive representations. Possible explanations for these results are discussed.

Chemical intolerance.

Chemical intolerance (CI) is a term used to describe a condition in which the sufferer experiences a complex array of recurrent unspecific symptoms attributed to low-level chemical exposure that most people regard as unproblematic. Severe CI constitutes the distinguishing feature of multiple chemical sensitivity (MCS). The symptoms reported by CI subjects are manifold, involving symptoms from multiple organs systems. In severe cases of CI, the condition can cause considerable life-style limitations with severe social, occupational and economic consequences. As no diagnostic tools for CI are available, the presence of the condition can only be established in accordance to criteria definitions. Numerous modes of action have been suggested to explain CI, with the most commonly discussed theories involving the immune system, central nervous system, olfactory and respiratory systems as well as altered metabolic capacity, behavioral conditioning and emotional regulation. However, in spite of more than 50 years of research, there is still a great deal of uncertainties regarding the event(s) and underlying mechanism( s) behind symptom elicitation. As a result, patients are often misdiagnosed or offered health care solutions with limited or no effect, and they experience being met with mistrust and doubt by health care professionals, the social care system and by friends and relatives. Evidence-based treatment options are currently unavailable, however, a person-centered care model based on a multidisciplinary treatment approach and individualized care plans have shown promising results. With this in mind, further research studies and health care solutions should be based on a multifactorial and interdisciplinary approach.

STUDY OF THE TOXIC EFFECTS OF FORMALDEHYDE VAPOURS WITHIN THE DISSECTION HALL ON THE FIRST YEAR INDIAN MEDICAL STUDENTS

Address for Correspondence: Dr Surajit Kundu, Assistant Professor, Department of Anatomy. Govt. Medical College, Raigarh (CG State) Pin: 496001. India. Ph: +918827264640. E-Mail: dr.surajitkundu@rediffmail.com *1 Assistant Professor, 2 Professor and HOD. Department of Anatomy, Govt. Medical College, Raigarh. (CG State)-496001. India. Introduction: Formaldehyde has been used since decades as a time tested embalming fluid material either alone or in mixture with methyl alcohol, thymol crystals, glycerin and water. We in Medical College, Raigarh use 37% formaldehyde, 7% methyl alcohol and the remaining water to prepare embalming solution for cadavers. The concentration of formaldehyde is usually expressed in terms of parts per million (1 ppm= 1.248 mg/cu.m.). Vapours emanating out of the cadavers within the dissection hall is a potential source of health hazard for all medical professionals, student, faculty or technicians. The discomfort includes irritation to the mucous membrane of the nose, respiratory tract, eyes and also causes allergic reaction of the skin. Materials and Methods: Keeping track of the unconsciously caused complaints, we made a sincere attempt to chalk out the effects of formaldehyde fumes on 100 first MBBS students of Medical College, Raigarh (C.G) as they are virgin in terms of formalin exposure. Results: The obtained results were quite dramatic. Maximum number of students was positive as among the various symptoms described. Discussion: Medical students during their dissection course are exposed to formaldehyde, whose exposure is recently considered to be one of the causes of multiple chemical sensitivity. The present study broadly reflects the toxic effects over the first MBBS Indian medical students Conclusion: The presentation also recommends possible methods for reduction of formalin exposure so that the medical students can enter the dissection hall without any mental tension of toxicity of formalin vapours.

Decreased work ability associated to indoor air problems – An intervention (RCT) to promote health behavior

IntroductionIndoor air problems may induce respiratory irritation and inflammation. In occupational settings, long-lasting non-specific building-related symptomatology, not fully medically explained, is encountered. The symptomatology may lead to illness, avoidance behavior and decreased work ability. In Finland, investigations of workers suspected of occupational asthma have revealed excess disability. There are no well-established clinical practices for the condition. ObjectiveThe aim was to develop a clinical intervention for patients with non-specific indoor air-related symptoms and decreased work ability. MethodsA randomized controlled trial including psychoeducation and promotion of health behavior was carried out in 55 patients investigated for causal relationship between work-related respiratory symptoms and moisture damaged workplaces. Inclusion criteria for disability was the work ability score (WAS)≤7 (scale 0–10) and indoor air-related sick leave ≥14 days the preceding year. After medical evaluation and the 3-session counseling intervention, follow-up at 6-months was assessed using self-evaluated work-ability, sick leave days, quality of life, and illness worries as outcome measures. ResultsThe mean symptom history was 55.5 months. 82% (45 out of 55) had asthma with normal lung function tests in most cases, although reporting abundant asthma symptoms. 81% of patients (39/48) had symptomatology from multiple organ systems without biomedical explanation, despite environmental improvements at work place. At the psychological counseling sessions, 15 (60%) patients of the intervention (INT, n=25) group showed concerns of a serious disease and in 5 (20%), concerns and fears had led to avoidance and restricted personal life. In the 6-month follow-up, the outcomes in the INT group did not differ from the treatment as usual group. ConclusionNo intervention effects were found. Patients shared features with medically unexplained symptoms and sick building syndrome or idiopathic environmental intolerance. Long environment-attributed non-specific symptom history and disability may require more intensive interventions. There is a need for improved recognition and early measures to prevent indoor-associated disability.Trial registration number: Single-center randomized controlled trial (ISRCTN33165676)

Commentary: Olfactory aversive conditioning during sleep reduces cigarette-smoking behavior.

Commentary: Olfactory aversive conditioning during sleep reduces cigarette-smoking behavior.

Is There a Connection Between Electrosensitivity and Electrosensibility? A Replication Study.

Among people with idiopathic environmental intolerance attributed to electromagnetic fields (IEI-EMF), a better than random detection ability for a 50-Hz 0.5-mT magnetic field (MF) and a propensity to experience more symptoms than controls was reported in a previous study. The current study aimed to replicate and clarify these results using a modified experimental design. Participants of the provocation experiment were 49 individuals with self-reported IEI-EMF and 57 controls. They completed the questionnaires (symptom expectations, Somatosensory Amplification Scale--SSAS, radiation subscale of the Modern Health Worries Scale--MHWS Radiation) and attempted to detect the presence of the MF directed to their right arm in 20 subsequent 1-min sessions. Symptom reports were registered after each session. Individuals with IEI-EMF as opposed to the control group showed a higher than random detection performance (d' index of signal detection theory), while no difference in their bias (β index) toward the presence of the MF was found. Predictors of reported symptoms were self-reported IEI-EMF and believed as opposed to actual presence of the MF. People with IEI-EMF reported significantly more symptoms particularly in the believed presence of the MF. IEI-EMF was closely related to MHWS Radiation and SSAS scores. People with IEI-EMF might be able to detect the presence of the MF to a small extent; however, their symptom reports are connected to perceived exposure.

Cortical activity during olfactory stimulation in multiple chemical sensitivity: a (18)F-FDG PET/CT study.

To investigate the differences in brain glucose consumption during olfactory stimulation between subjects affected by multiple chemical sensitivity (MCS) and a group of healthy individuals. Two (18)F-FDG PET/CT scans were performed in 26 subjects (6 men and 20 women; mean age 46.7 ± 11years) with a clinical diagnosis of MCS and in 11 healthy controls (6 women and 5 men; mean age 45.7 ± 11years), the first scan after a neutral olfactory stimulation (NS) and the second after a pure olfactory stimulation (OS). Differences in (18)F-FDG uptake were analysed by statistical parametric mapping (SPM2). In controls OS led to an increase in glucose consumption in BA 18 and 19 and a reduction in glucose metabolism in BA 10, 11, 32 and 47. In MCS subjects, OS led to an increase in glucose consumption in BA 20, 23, 18 and 37 and a reduction in glucose metabolism in BA 8, 9 and 10. The results of our study suggest that cortical activity in subjects with MCS differs from that in healthy individuals during olfactory stimulation.

Assessment of cerebral blood flow in patients with multiple chemical sensitivity using near-infrared spectroscopy--recovery after olfactory stimulation: a case-control study.

Multiple chemical sensitivity (MCS) is a chronic acquired disorder characterized by non-specific symptoms in multiple organ systems associated with exposure to odorous chemicals. We previously observed significant activations in the prefrontal cortex (PFC) during olfactory stimulation using several different odorants in patients with MCS by near-infrared spectroscopy (NIRS) imaging. We also observed that the patients with MCS did not adequately distinguish non-odorant in the late stage of the repeated olfactory stimulation test. The sensory recovery of the olfactory system in the patients with MCS may process odors differently from healthy subjects after olfactory stimulation. We examined the recovery process of regional cerebral blood flow (rCBF) after olfactory stimulation in patients with MCS. NIRS imaging was performed in 6 patients with MCS and in 6 controls. The olfactory stimulation test was continuously repeated 10 times. The study also included a subjective assessment of the physical and psychological status and of the perception of irritating and hedonic odors. After olfactory stimulation, significant activations were observed in the PFC of patients with MCS on both the right and left sides compared with controls. The activations were specifically strong in the orbitofrontal cortex (OFC). Compared with controls, autonomic perception and feelings identification were poorer in patients with MCS. OFC is associated with stimuli response and the representation of preferences. These results suggest that a past strong exposure to hazardous chemicals activates the PFC during olfactory stimuli in patients with MCS, and a strong activation in the OFC remains after the stimuli.

Actual and perceived exposure to electromagnetic fields and non-specific physical symptoms: an epidemiological study based on self-reported data and electronic medical records.

There is continuing scientific debate and increasing public concern regarding the possible effects of electromagnetic fields (EMF) on general population's health. To date, no epidemiological study has investigated the possible association between actual and perceived EMF exposure and non-specific physical symptoms (NSPS) and sleep quality, using both self-reported and general practice (GP)-registered data. A health survey of adult (≥ 18) participants (n=5933) in the Netherlands was combined with the electronic medical records (EMRs) of NSPS as registered by general practitioners. Characterization of actual exposure was based on several proxies, such as prediction models of radiofrequency (RF)-EMF exposure, geo-coded distance to high-voltage overhead power lines and self-reported use/distance of/to indoor electrical appliances. Perceived exposure and the role of psychological variables were also examined. Perceived exposure had a poor correlation with the actual exposure estimates. No significant association was found between modeled RF-EMF exposure and the investigated outcomes. Associations with NSPS were observed for use of an electric blanket and close distance to an electric charger during sleep. Perceived exposure, perceived control and avoidance behavior were associated with the examined outcomes. The association between perceived exposure was stronger for self-reported than for GP-registered NSPS. There was some indication, but no consistent pattern for an interaction between idiopathic environmental intolerance (IEI-EMF) and the association between actual exposure and NSPS. In conclusion, there is no convincing evidence for an association between everyday life RF-EMF exposure and NSPS and sleep quality in the population. Better exposure characterization, in particular with respect to sources of extremely low frequency magnetic fields (ELF-MF) is needed to draw more solid conclusions. We argue that perceived exposure is an independent determinant of NSPS.

Aggregated data from two double-blind base station provocation studies comparing individuals with idiopathic environmental intolerance with attribution to electromagnetic fields and controls.

Data from two previous studies were aggregated to provide a statistically powerful test of whether exposure to electromagnetic fields (EMFs) produced by telecommunication base stations negatively affects well-being in individuals who report idiopathic environmental illness with attribution to electromagnetic fields (IEI-EMF) and control participants. A total of 102 IEI-EMF and 237 controls participated in open provocation trials and 88 IEI-EMF and 231 controls went on to complete double-blind trials in which they were exposed to EMFs from a base station emitting either a Global System for Mobile Communication and Universal Mobile Telecommunications System or a Terrestrial Trunked Radio Telecommunications System signal. Both experiments included a comparison sham condition. Visual analog and symptom scales measured subjective well-being. Results showed that IEI-EMF participants reported lower levels of well-being during real compared to sham exposure during open provocation, but not during double-blind trials. Additionally, participants reported lower levels of well-being during high compared to low load trials and this did not interact with radiofrequency-EMF exposure. These findings are consistent with a growing body of literature indicating there is no causal relationship between short-term exposure to EMFs and subjective well-being in members of the public whether or not they report perceived sensitivity to EMFs.

Role of polymorphisms of inducible nitric oxide synthase and endothelial nitric oxide synthase in idiopathic environmental intolerances.

Oxidative stress and inflammation play a pathogenetic role in idiopathic environmental intolerances (IEI), namely, multiple chemical sensitivity (MCS), fibromyalgia (FM), and chronic fatigue syndrome (CFS). Given the reported association of nitric oxide synthase (NOS) gene polymorphisms with inflammatory disorders, we aimed to investigate the distribution of NOS2A −2.5 kb (CCTTT)n as well as Ser608Leu and NOS3 −786T>C variants and their correlation with nitrite/nitrate levels, in a study cohort including 170 MCS, 108 suspected MCS (SMCS), 89 FM/CFS, and 196 healthy subjects. Patients and controls had similar distributions of NOS2A Ser608Leu and NOS3 −786T>C polymorphisms. Interestingly, the NOS3 −786TT genotype was associated with increased nitrite/nitrate levels only in IEI patients. We also found that the NOS2A −2.5 kb (CCTTT)11 allele represents a genetic determinant for FM/CFS, and the (CCTTT)16 allele discriminates MCS from SMCS patients. Instead, the (CCTTT)8 allele reduces by three-, six-, and tenfold, respectively, the risk for MCS, SMCS, and FM/CFS. Moreover, a short number of (CCTTT) repeats is associated with higher concentrations of nitrites/nitrates. Here, we first demonstrate that NOS3 −786T>C variant affects nitrite/nitrate levels in IEI patients and that screening for NOS2A −2.5 kb (CCTTT)n polymorphism may be useful for differential diagnosis of various IEI.

The implications of non-linear biological oscillations on human electrophysiology for electrohypersensitivity (EHS) and multiple chemical sensitivity (MCS).

The 'informational content' of Earth's electromagnetic signaling is like a set of operating instructions for human life. These environmental cues are dynamic and involve exquisitely low inputs (intensities) of critical frequencies with which all life on Earth evolved. Circadian and other temporal biological rhythms depend on these fluctuating electromagnetic inputs to direct gene expression, cell communication and metabolism, neural development, brainwave activity, neural synchrony, a diversity of immune functions, sleep and wake cycles, behavior and cognition. Oscillation is also a universal phenomenon, and biological systems of the heart, brain and gut are dependent on the cooperative actions of cells that function according to principles of non-linear, coupled biological oscillations for their synchrony. They are dependent on exquisitely timed cues from the environment at vanishingly small levels. Altered 'informational content' of environmental cues can swamp natural electromagnetic cues and result in dysregulation of normal biological rhythms that direct growth, development, metabolism and repair mechanisms. Pulsed electromagnetic fields (PEMF) and radiofrequency radiation (RFR) can have the devastating biological effects of disrupting homeostasis and desynchronizing normal biological rhythms that maintain health. Non-linear, weak field biological oscillations govern body electrophysiology, organize cell and tissue functions and maintain organ systems. Artificial bioelectrical interference can give false information (disruptive signaling) sufficient to affect critical pacemaker cells (of the heart, gut and brain) and desynchronize functions of these important cells that orchestrate function and maintain health. Chronic physiological stress undermines homeostasis whether it is chemically induced or electromagnetically induced (or both exposures are simultaneous contributors). This can eventually break down adaptive biological responses critical to health maintenance; and resilience can be compromised. Electrohypersensitivity can be caused by successive assaults on human bioelectrochemical dynamics from exogenous electromagnetic fields (EMF) and RFR or a single acute exposure. Once sensitized, further exposures are widely reported to cause reactivity to lower and lower intensities of EMF/RFR, at which point thousand-fold lower levels can cause adverse health impacts to the electrosensitive person. Electrohypersensitivity (EHS) can be a precursor to, or linked with, multiple chemical sensitivity (MCS) based on reports of individuals who first develop one condition, then rapidly develop the other. Similarity of chemical biomarkers is seen in both conditions [histamines, markers of oxidative stress, auto-antibodies, heat shock protein (HSP), melatonin markers and leakage of the blood-brain barrier]. Low intensity pulsed microwave activation of voltage-gated calcium channels (VGCCs) is postulated as a mechanism of action for non-thermal health effects.

Scombrotoxinism: Protracted Illness following Misdiagnosis in the Emergency Department.

Background. Scombrotoxinism is an acute toxin-induced illness caused primarily by bacterial synthesis of histamine in decomposed fish. Case Report. Immediately after taking 2-3 bites of cooked salmon, a clerical worker developed oral burning, urticaria, and asthma. In the emergency department, she was diagnosed with “allergies”; scombrotoxinism was never considered. She then developed wide-ranging symptoms (e.g., chronic fatigue, asthma, anxiety, multiple chemical sensitivity, and paresthesiae) and saw many specialists (in pulmonology, otorhinolaryngology, allergy, toxicology, neurology, psychology, and immunology). During the next 500+ days, she had extensive testing (allergy screens, brain MRI, electroencephalogram, electromyogram, nerve conduction velocity, heavy metal screen, and blood chemistry) with essentially normal results. She filed a workers' compensation claim since this injury occurred following a business meal. She was evaluated by a Qualified Medical Evaluator (GL) on day 504, who diagnosed scombrotoxinism. Comment. Scombrotoxinism should be considered in all patients presenting to the emergency department with “oral burning” or allergy symptoms following “fish consumption.” Initial attention to such history would have led to a correct diagnosis and averted this patient's extended illness. Specialist referrals and tests should be ordered only if clinically indicated and not for diagnostic fishing expedition. Meticulous history is crucial in resolving clinical dilemmas.

The correlation between mental health and multiple chemical sensitivity: a survey study in Japanese workers.

This study was designed to determine the correlation between mental health and multiple chemical sensitivity (MCS). The present study was conducted at two companies in 2011; both in Kyushu, Japan. The "subjective symptoms" subscale of the "Self-diagnosis Checklist for Assessment of Workers' Accumulated Fatigue" was used as a mental health subscale. To determine if multiple chemical exposure has an impact on mental health, we composed an original path model using structural equation analysis. Our final path model can be regarded as good: CMIN/DF = 1.832, CFI = 0.996, and RMSEA = 0.038, AIC = 71.158. As expected, chemical sensitivity and other chemical sensitivity scores predicted the health effects of multiple chemical exposure (β = 0.19, 0.64). Mental health was predicted by symptom severity and life impact (β = 0.56 and 0.12), which were both affected by multiple chemical exposure (β = 0.38 and 0.89, respectively). As far as we are aware, this is the first study using path analysis to explore whether MCS can indicate mental health in worker populations worldwide, and we found a significant causal relationship between them. This could indicate that more focus should be placed on the impact of MCS on mental health in future investigations.

Characteristics of Olfactory Threshold and Cerebral Blood Flow during Olfactory Stimulation in Patients with Multiple Chemical Sensitivity

Multiple chemical sensitivity (MCS) is characterized by somatic distress upon exposure to odors. However, the underlying mechanisms are not well understood. Patients with MCS process odors differen...

Spatial Variation and Influence of Marginalization in Cumulative Incidence of Multiple Chemical Sensitivity

Spatial Variation and Influence of Marginalization in Cumulative Incidence of Multiple Chemical SensitivityAbstract Number:2305 Daniel Rainham*, Patrick Brown, and Tara Sampalli Daniel Rainham* Dalhousie University, Canada, E-mail Address: [email protected] Search for more papers by this author , Patrick Brown University of Toronto, Canada, E-mail Address: [email protected] Search for more papers by this author , and Tara Sampalli Capital Health, Canada, E-mail Address: [email protected] Search for more papers by this author AbstractMultiple chemical sensitivity (MCS), or environmental illness, is a chronic, acquired condition characterized by recurring and increasingly severe symptoms in many body systems triggered by exposures to low levels of toxicants or anthropogenic pollution. The role of marginalization and contextual factors on the spatial structure of MCS incidence remains unexplored. Aims: Our study aimed to assess the spatial structure of MCS incidence and estimate the contribution of marginalization to variations in rates of MCS at the community level.Methods: Administrative patient data were used to calculate cumulative incidence rate ratios for treated multiple chemical sensitivities. Home addresses were geocoded and linked to small area census geography to calculate age-, sex-adjusted rates. Spatial variation was modeled using conditional spatial random effects. Posterior distributions for parameters and random effects were employed for non-gaussian data using the R-INLA package in R. An autoregressive conditional model was used to calculate small area relative risks. Adjusted models estimated the influence of community-level marginalization.Results: A total of 1,091 cases of MCS were identified, 86% female and a median age of 56 years (11-93 years). Cases are distributed evenly across urban (34%), suburban (35%) and rural (31%) communities. No discernible spatial pattern was evident for SIR’s of MCS. Relative risks were higher in rural communities. Cluster-outlier analysis showed evidence of high relative risk clusters in urban areas, and low risk clusters in the north of the province. We observed odds ratios (OR) of associations between risk of MCS and community instability (OR:1.37, 95%CI: 1.12-1.68), and dependency (OR: 0.74, 95%CI: 0.59-0.92).Conclusion:Results from this study indicate spatial pattern in risk of MCS and that, in addition to individual factors, community indicators of marginalization are also important in the quest for the determination of MCS etiology.

From individual coping strategies to illness codification: the reflection of gender in social science research on Multiple Chemical Sensitivities (MCS)

IntroductionEmerging fields such as environmental health have been challenged, in recent years, to answer the growing methodological calls for a finer integration of sex and gender in health-related research and policy-making.MethodsThrough a descriptive examination of 25 peer-reviewed social science papers published between 1996 and 2011, we explore, by examining methodological designs and theoretical standpoints, how the social sciences have integrated gender sensitivity in empirical work on Multiple Chemical Sensitivities (MCS). MCS is a “diagnosis” associated with sensitivities to chronic and low-dose chemical exposures, which remains contested in both the medical and institutional arenas, and is reported to disproportionately affect women.ResultsWe highlighted important differences between papers that did integrate a gender lens and those that did not. These included characteristics of the authorship, purposes, theoretical frameworks and methodological designs of the studies. Reviewed papers that integrated gender tended to focus on the gender roles and identity of women suffering from MCS, emphasizing personal strategies of adaptation. More generally, terminological confusions in the use of sex and gender language and concepts, such as a conflation of women and gender, were observed. Although some men were included in most of the study samples reviewed, specific data relating to men was undereported in results and only one paper discussed issues specifically experienced by men suffering from MCS. Papers that overlooked gender dimensions generally addressed more systemic social issues such as the dynamics of expertise and the medical codification of MCS, from more consistently outlined theoretical frameworks. Results highlight the place for a critical, systematic and reflexive problematization of gender and for the development of methodological and theoretical tools on how to integrate gender in research designs when looking at both micro and macro social dimensions of environmental health conditions.ConclusionsThis paper contributes to a discussion on the methodological and policy implications of taking sex and gender into account appropriately in order to contribute to better equity in health, especially where the critical social contexts of definition and medico-legal recognition play a major role such as in the case of MCS.