Kathie Kelly-McNeil

A Controlled Comparison of Multiple Chemical Sensitivities and Chronic Fatigue Syndrome

The present study had two objectives 1) to determine the characteristics that differentiated subjects with multiple chemical sensitivities (MCS), chemical sensitivities (CS), and chronic fatigue syndrome (CFS); and 2) to evaluate the psychiatric and neuropsychological complaints of these groups relative to normal controls. A cross-sectional comparison was made of the following groups matched for age, sex, and education: 1) patients whose sensitivities to multiple low level chemical exposures began with a defined exposure (MCS; N = 23); 2) patients with sensitivities to multiple chemicals without a clear date of onset (CS; N = 13); 3) patients meeting CDC criteria for Chronic Fatigue Syndrome (CFS; N = 18); and 4) normal controls (N = 18). Subjects with sensitivities to chemicals (MCS and CS) reported significantly more lifestyle changes due to chemical sensitivities and significantly more chemical substances that made them ill compared with chronic fatigue and normal controls. MCS, CS, and CFS patients had significantly higher rates of current psychiatric disorders than normal controls and reported significantly more physical symptoms with no medical explanation. Seventy-four percent of MCS and 61% of CFS did not qualify for any current Axis I psychiatric diagnosis. Chemically sensitive subjects without a defined date of onset (CS) had the highest rate of Axis I psychiatric disorders (69%). On the MMPI-2, 44% of MCS, 42% of CS, 53% of CFS, and none of the controls achieved clinically significant elevations on scales associated with somatoform disorders. With the exception of one complex test of visual memory, no significant differences were noted among the groups on tests of neuropsychological function. Standardized measures of psychiatric and neuropsychological function did not differentiate subjects with sensitivities to chemicals from those with chronic fatigue. Subjects with sensitivities to chemicals and no clear date of onset had the highest rate of psychiatric morbidity. Standardized neuropsychological tests did not substantiate the cognitive impairment reported symptomatically. Cognitive deficits may become apparent under controlled exposure conditions.

Long-term use of organophosphates and neuropsychological performance

This study evaluated neuropsychological effects due to chronic organophosphate use among farmers with no history of acute poisoning. Fifty-seven male tree fruit farmers (exposed) were compared with 42 age-matched male cranberry/blueberry growers and hardware store owners (unexposed). Univariate analyses of covariance (reading test as covariate) comparing exposed and unexposed subjects revealed significantly slower reaction time. No other significant differences were noted on tests of concentration, visuomotor skills, memory, expressive language, or mood. Based on an exposure metric derived from detailed exposure histories, farmers were divided into high exposure (n = 40) and low exposure (n = 59) groups, and their neuropsychological performance was compared. Analysis of covariance with age and reading test score as covariates revealed that the high exposure group had significantly slower reaction time, dominant hand. Long-term use of organophosphates without evidence of an acute poisoning episode appears to produce, at most, subtle changes in neuropsychological performance.

Health Effects of a Mixture of Indoor Air Volatile Organics, Their Ozone Oxidation Products, and Stress

In our present study we tested the health effects among women of controlled exposures to volatile organic compounds (VOCs), with and without ozone (O3), and psychological stress. Each subject was exposed to the following three conditions at 1-week intervals (within-subject factor): VOCs (26 mg/m3), VOCs + O3 (26 mg/m3 + 40 ppb), and ambient air with a 1-min spike of VOCs (2.5 mg/m3). As a between-subjects factor, half the subjects were randomly assigned to perform a stressor. Subjects were 130 healthy women (mean age, 27.2 years; mean education, 15.2 years). Health effects measured before, during, and after each 140-min exposure included symptoms, neurobehavioral performance, salivary cortisol, and lung function. Mixing VOCs with O3 was shown to produce irritating compounds including aldehydes, hydrogen peroxide, organic acids, secondary organic aerosols, and ultrafine particles (particulate matter with aerodynamic diameter < 0.1 μm). Exposure to VOCs with and without O3 did not result in significant subjective or objective health effects. Psychological stress significantly increased salivary cortisol and symptoms of anxiety regardless of exposure condition. Neither lung function nor neurobehavioral performance was compromised by exposure to VOCs or VOCs + O3. Although numerous epidemiologic studies suggest that symptoms are significantly increased among workers in buildings with poor ventilation and mixtures of VOCs, our acute exposure study was not consistent with these epidemiologic findings. Stress appears to be a more significant factor than chemical exposures in affecting some of the health end points measured in our present study.

Anxiety sensitivity and depression in multiple chemical sensitivities and asthma

Learning ObjectivesExplain why asthmatic patients were used as a patient control group in this study of the role of psychiatric abnormality in patients with multiple chemical sensitivities (MCS).Recall the difference among MCS patients, asthmatics, and normal control subjects in psychiatric history, current psychiatric illness. and neuropsychological function.Comment on the therapeutic implications of the present findings for MCS patients. Patients with sensitivities to multiple chemicals report symptoms of cognitive dysfunction, respiratory distress, and mood disturbance. Lifetime and current psychiatric disorders, personality traits associated with symptom reporting, and tests of cognitive function were compared between 30 subjects with Multiple Chemical Sensitivities (MCS), 19 asthmatics, and 31 healthy controls. Relative to asthmatics and controls, more MCS subjects met criteria for current depression and somatization disorder. MCS subjects and asthmatics scored significantly higher than controls on scales of chemical odor intolerance and anxiety sensitivity, both of which were significant predictors of physical symptoms. Few differences on objective neuropsychological tests were noted. However, MCS subjects with comorbid depression performed significantly worse on a verbal memory test relative to asthmatics but not to controls. Anxiety and depression are significant contributors to the physical and cognitive symptoms of MCS subjects.

Odor perception: multiple chemical sensitivities, chronic fatigue, and asthma.

Patients with multiple chemical sensitivities (MCS) often report heightened sensitivity to odors. Odor detection thresholds to phenyl ethyl alcohol (PEA) and pyridine (PYR) were evaluated as a measure of odor sensitivity for 33 MCS subjects, 13 chronic fatigue syndrome subjects, 16 asthmatic subjects, and 27 healthy controls. Odor identification ability (based on University of Pennsylvania Smell Identification Test results) and ratings in response to four suprathreshold levels of PEA and PYR were also assessed. Odor detection thresholds for PEA and PYR and odor identification ability were equivalent for all groups; however, when exposed to suprathreshold concentrations of PEA, MCS subjects reported significantly more trigeminal symptoms and lower esthetic ratings of PEA. No group differences were found in response to suprathreshold concentrations of PYR. In summary, MCS subjects did not demonstrate lower olfactory threshold sensitivity or enhanced ability to identify odors accurately. Furthermore, they were differentiated from the other groups in their symptomatic and esthetic ratings of PEA, but not PYR.

Health Effects of MTBE Among New Jersey Garage Workers

AbstractMethyl tertiary butyl ether (MTBE) is an oxygenated additive used in the 1993 wintertime oxyfuel program to reduce tailpipe carbon monoxide emissions. Because of complaints of acute health symptoms, particularly in the state of Alaska, this program was terminated prematurely in that state. We designed a cross-sectional cohort study of self-reported symptoms of garage workers in the state of New Jersey exposed to high and low MJBE concentration environments. Two hundred and thirty-seven participants were divided into 2 groups: 115 workers in northern New jersey sampled during the wintertime oxyfuel program, and 122 workers in southern New jersey 10 wk after the phase-out date for the program in that area. The outcome measures included a list of symptoms, of which some were felt to be attributable to MTBE exposure. Participants were asked to indicate the frequency of those symptoms they had experienced over the last 30 days. In addition, workers were given identical preshilt and postshift questionna...

Nasal effects of a mixture of volatile organic compounds and their ozone oxidation products.

Objective:Our objective was to determine if low levels of a mixture of volatile organic compounds (VOCs) and their ozone (O3) oxidation products, similar to what might be found in “sick buildings,” cause nasal irritation and inflammation under controlled exposure conditions. Methods:Healthy, nonsmoking women (n = 130) completed 2-hour controlled exposures to VOCs, VOCs and O3, and a masked air “MA” control in random order at least 1 week apart. VOCs and O3 concentrations were approximately 25 mg/m3 and approximately 40 ppb, respectively. Nasal symptoms were rated before, during, and after exposure. Nasal lavage fluid was analyzed for polymorphonuclear cells, total protein, interleukin-6, and interleukin-8. Results:We found no significant differences in symptoms or markers of nasal inflammation between exposure conditions. Conclusions:Results suggest that VOCs and their oxidation products may not cause acute nasal effects at low concentrations.

Responses to controlled diesel vapor exposure among chemically sensitive Gulf War veterans

Objective: A significant proportion of Gulf War veterans (GWVs) report chemical sensitivity, fatigue, and unexplained symptoms resulting in ongoing disability. GWVs frequently recall an association between diesel and petrochemical fume exposure and symptoms during service. The purpose of the present study among GWVs was to evaluate the immediate health effects of acute exposure to chemicals (diesel vapors with acetaldehyde) with and without stress. Methods: In a single, controlled exposure to 5 parts per million (ppm) diesel vapors, symptoms, odor ratings, neurobehavioral performance, and psychophysiologic responses of 12 ill GWVs (GWV-I) were compared with 19 age- and gender-matched healthy GWVs (GWV-H). Results: Relative to baseline and to GWV-H, GWV-I reported significantly increased symptoms such as disorientation and dizziness and displayed significantly reduced end-tidal CO2 just after the onset of exposure. As exposure increased over time, GWV-I relative to GWV-H reported significantly increased symptoms of respiratory discomfort and general malaise. GWV-I were also physiologically hyporeactive in response to behavioral tasks administered during but not before exposure. Conclusions: Current symptoms among GWV-I may be exacerbated by ongoing environmental chemical exposures reminiscent of the Gulf War. Both psychologic and physiologic mechanisms contribute to current symptomatic responses of GWV-I.

Quantification of 1-aminopyrene in human urine after a controlled exposure to diesel exhaust

Diesel exhaust (DE) is a significant source of air pollution that has been linked to respiratory and cardiovascular morbidity and mortality. Many components in DE, such as polycyclic aromatic hydrocarbons, are present in the environment from other sources. 1-Nitropyrene appears to be a more specific marker of DE exposure. 1-Nitropyrene is partially metabolized to 1-aminopyrene and excreted in urine. We developed a practical, sensitive method for measuring 1-aminopyrene in human urine using a HPLC-fluorescence technique. We measured 1-aminopyrene concentrations in spot urine samples collected prior to and during 24 h following the start of 1 h controlled exposures to DE (target concentration 300 microg m(-3) as PM(10)) and clean air control. Time-weighted-average concentrations of urinary 1-aminopyrene were significantly greater following the DE exposure compared to the control (median 138.7 ng g(-1) creatinine vs. 21.7 ng g(-1) creatinine, p < 0.0001). Comparing DE to control exposures, we observed significant increases in 1-aminopyrine concentration from pre-exposure to either first post-exposure void or peak spot urine concentration following exposure (p = 0.027 and p = 0.0026, respectively). Large inter-individual variability, in both the concentration of urinary 1-aminopyrene and the time course of appearance in the urine following the standardized exposure to DE, suggests the need to explore subject variables that may affect conversion of inhaled 1-nitropyrene to urinary excretion of 1-aminopyrene.

Sensory and Cognitive Effects of Acute Exposure to Hydrogen Sulfide

Background Some epidemiologic studies have reported compromised cognitive and sensory performance among individuals exposed to low concentrations of hydrogen sulfide (H2S). Objectives We hypothesized a dose–response increase in symptom severity and reduction in sensory and cognitive performance in response to controlled H2S exposures. Methods In separate exposure sessions administered in random order over three consecutive weeks, 74 healthy subjects [35 females, 39 males; mean age (± SD) = 24.7 ± 4.2; mean years of education = 16.5 ± 2.4], were exposed to 0.05, 0.5, and 5 ppm H2S. During each exposure session, subjects completed ratings and tests before H2S exposure (baseline) and during the final hour of the 2-hr exposure period. Results Dose–response reduction in air quality and increases in ratings of odor intensity, irritation, and unpleasantness were observed. Total symptom severity was not significantly elevated across any exposure condition, but anxiety symptoms were significantly greater in the 5-ppm than in the 0.05-ppm condition. No dose–response effect was observed for sensory or cognitive measures. Verbal learning was compromised during each exposure condition. Conclusions Although some symptoms increased with exposure, the magnitude of these changes was relatively minor. Increased anxiety was significantly related to ratings of irritation due to odor. Whether the effect on verbal learning represents a threshold effect of H2S or an effect due to fatigue across exposure requires further investigation. These acute effects in a healthy sample cannot be directly generalized to communities where individuals have other health conditions and concomitant exposures.