Traffic-related air pollution, chronic stress, and changes in exhaled nitric oxide and lung function among a panel of children with asthma living in an underresourced community

We examined associations between short-term exposure to traffic-related air pollutants (TRAP) and airway inflammation and lung function in children with asthma, and whether these associations are modified by chronic psychological stress. Residents of underresourced port-adjacent communities in New Jersey were concerned about the cumulative impacts of exposure to TRAP, particularly diesel-engine truck emissions, and stress on exacerbation of asthma among children. Children with asthma aged 9-14 (n = 35) were recruited from non-smoking households. We measured each participant's (1) continuous personal exposure to black carbon (BC, a surrogate of TRAP) at 1-min intervals, (2) 24-h integrated personal exposure to nitrogen dioxide (NO2), (3) daily fractional exhaled nitric oxide (FeNO), and (4) lung function for up to 30 consecutive days. Personal BC was recorded by micro-aethalometers. We measured daily FeNO using the NIOX MINO, forced expiratory volume in one second (FEV1), and forced vital capacity (FVC) using Easy One Frontline spirometers. Chronic stress was measured with the UCLA Life Stress Interview for Children. The association was examined using linear mixed-effect models. In the fully adjusted model, an interquartile range (IQR) increase in BC at lag 0-6 h before the FeNO measurement was associated with 8 % (95 % CI: 3 % - 12 %) increase in FeNO, whereas an IQR increase in BC at lag 7-12 h and lag 0-24 h were associated with 6 % (95 % CI: 2 % - 11 %) and 7 % (2 % - 12 %) FeNO increases, respectively. There were no significant lung function changes per IQR increase in BC. No interactions were observed between chronic stress and BC on FeNO. Chronic stress was negatively associated with individual average FeNO levels. Our findings suggest that higher levels of BC exposure within the prior 24 h increased airway inflammation levels in children with asthma, with the strongest effect observed within the first 6 h.

Exposure to traffic-related air pollution and changes in exhaled nitric oxide and DNA methylation in arginase and nitric oxide synthase in children with asthma

BACKGROUND

Traffic-related air pollution (TRAP) has been associated with increased risk of airway inflammation in children with asthma. While epigenetic changes could potentially modulate TRAP-induced inflammatory responses, few studies have assessed the temporal pattern of exposure to TRAP, epigenetic changes and inflammation in children with asthma. Our goal was to test the time-lag patterns of personal exposure to TRAP, airway inflammation (measured as fractional exhaled nitric oxide, FeNO), and DNA methylation in the promoter regions of genes involved in nitric oxide synthesis among children with asthma.

METHODS

We measured personal exposure to black carbon (BC) and FeNO for up to 30 days in a panel of children with asthma. We collected 90 buccal cell samples for DNA methylation analysis from 18 children (5 per child). Methylation in promoter regions of nitric oxide synthase (NOS1, NOS2A, NOS3) and arginase (ARG1, ARG2) was assessed by bisulfite pyrosequencing. Linear-mixed effect models were used to test the associations of BC at different lag periods, percent DNA methylation at each site and FeNO level.

RESULTS

Exposure to BC was positively associated with FeNO, and negatively associated with DNA methylation in NOS3. We found strongest association between FeNO and BC at lag 0-6 h while strongest associations between methylation at positions 1 and 2 in NOS3 and BC were at lag 13-24 h and lag 0-24 h, respectively. The strengths of associations were attenuated at longer lag periods. No significant associations between exposure to TRAP and methylation levels in other NOS and ARG isoforms were observed.

CONCLUSIONS

Exposure to TRAP was associated with higher levels of FeNO and lower levels of DNA methylation in the promoter regions of the NOS3 gene, indicating that DNA methylation of the NOS3 gene could be an important epigenetic mechanism in physiological responses to TRAP in children with asthma.

Development of solvent exposure index for construction painters

This article describes methodological approaches for reconstructing long-term occupational exposure to organic solvents among construction painters. A detailed exposure questionnaire was administered to 125 painters to develop a job exposure matrix (JEM). The questionnaire inquired about painting activities with solvent-based paints and use of protection equipment for the previous 25 years in 5-year intervals. Current and historical distributions of solvent air concentrations were assessed for the same time period based on the following information: industrial hygiene measurements, paint composition changes, and VOC emission rate changes from architectural and industrial maintenance coatings. Changes in protection factors of respirators were also assessed. A cumulative solvent exposure index was calculated for each painter through Monte Carlo simulations by combining appropriate input distributions of solvent air concentrations and protection factors of respirators with JEM. Sensitivity simulations revealed that the historical variations in solvent air concentrations had a higher impact on the cumulative solvent exposure index than changes in protection factors for respirators. Fifty-eight percent of painters were classified with a different exposure quartile when the solvent exposure index was used vs. an exposure based only on years using solvent-based paints, suggesting the need for more detailed exposure analysis than just years working when conducting epidemiologic studies for this worker population.

Genotype-dependent activation or repression of HBV enhancer II by transcription factor COUP-TF1

AIM

To study the expression of HBV enhancer II by transcription factor COUP-TF1.

METHODS

In order to study the regulation of HBV variants in the vicinity of the NRRE we cloned luciferase constructs containing the HBV enhancer II from variants and from HBV genotypes A and D and cotransfected them together with expression vectors for COUP-TF1 into HepG2 cells.

RESULTS

Our findings show that enhancer II of HBV genotype A is also repressed by COUP-TF1. In contrast, two different enhancer II constructs of HBV genotype D were activated by COUP-TF1. The activation was independent of the NRRE because a natural variant with a deletion of nt 1763-1770 was still activated by COUP-TF1.

CONCLUSION

Regulation of transcription of the HBV genome seems to differ among HBV genomes derived from different genotypes. These differences in transcriptional control among HBV genotypes may be the molecular basis for differences in the clinical course among HBV genotypes.

Differential effects on apoptosis induction in hepatocyte lines by stable expression of hepatitis B virus X protein

AIM: Hepatitis B virus protein X (HBx) has been shown to be weakly oncogenic in vitro. The transforming activities of HBx have been linked with the inhibition of several functions of the tumor suppressor p53. We have studied whether HBx may have different effects on p53 depending on the cell type.

METHODS: We used the human hepatoma cell line HepG2 and the immortalized murine hepatocyte line AML12 and analyzed stably transfected clones which expressed physiological amounts of HBx. P53 was induced by UV irradiation.

RESULTS: The p53 induction by UV irradiation was unaffected by stable expression of HBx. However, the expression of the cyclin kinase inhibitor p21^waf/cip/sdi which gets activated by p53 was affected in the HBx transformed cell line AML12-HBx9, but not in HepG2. In AML-HBx9 cells, p21^waf/cip/sdi-protein expression and p21^waf/cip/sdi transcription were deregulated. Furthermore, the process of apoptosis was affected in opposite ways in the two cell lines investigated. While stable expression of HBx enhanced apoptosis induced by UV irradiation in HepG2-cells, apoptosis was decreased in HBx transformed AML12-HBx9. P53 repressed transcription from the HBV enhancer I, when expressed from expression vectors or after induction of endogenous p53 by UV irradiation. Repression by endogenous p53 was partially reversible by stably expressed HBx in both cell lines.

CONCLUSION: Stable expression of HBx leads to deregulation of apoptosis induced by UV irradiation depending on the cell line used. In an immortalized hepatocyte line HBx acted anti-apoptotic whereas expression in a carcinoma derived hepatocyte line HBx enhanced apoptosis.

Suppression of hepatitis B virus enhancer 1 and 2 by hepatitis C virus core protein

BACKGROUND/AIMS

Epidemiological studies have shown that coinfection or superinfection with hepatitis B virus (HBV) and C virus (HCV) frequently leads to the suppression of hepatitis B virus replication. The mechanism of this phenomenon is still unclear. Shih et al. [J Virol 1993;67:5823] reported a direct suppression of HBV replication by the core protein of HCV. The target structure of HCV core protein in this system remained unclear.

METHODS

As HCV core protein has been shown to influence expression from transcriptional elements, we studied whether HCV core protein altered the activity of the two HBV enhancers 1 and 2. Luciferase vectors for HBV enhancers 1 or 2 were cotransfected with expression constructs for HCV core protein in murine and human hepatocyte lines.

RESULTS

Full-length HCV core protein suppressed the HBV enhancer 1 up to 11-fold, the enhancer 2 3-4-fold. Suppression of HBV enhancer 1 by HCV core from genotype 1b was stronger than by HCV core of genotypes 3a or 1a. Carboxyterminally truncated core proteins had lower or no suppression activity.

CONCLUSIONS

These data suggest that HCV core protein may directly repress transcription of the HBV RNAs. This trans-repression may contribute to suppression of HBV replication in patients coinfected with both viruses.

Optimised conditions for the production of hepatitis B virus from cell culture

In chronically infected patients, hepatitis B virus (HBV) particles reach numbers as large as >10(9) genome equivalents (GE)/ml of serum. However, expression of infectious HBV particles in cell culture only yields 10(5)-10(6) GE/ml, which is insufficient for many studies. HBV transcription and possibly replication is dependent on hepatocyte-specific differentiation. Thus, we tested several cell culture parameters that have been reported to enhance the expression of hepatocyte-specific markers, such as growth on different extracellular matrices, different cell culture media, low concentrations of fetal calf serum (FCS) and the addition of dimethyl sulfoxide (DMSO) to the medium. Lower concentrations of FCS, growth on collagen and inclusion of DMSO in the medium only moderately enhanced HBV production in vitro when applied individually. However, combinations of these parameters optimised cell culture conditions and reproducibly increased the release of HBV particles about 100-fold to titres >10(8) GE/ml of culture medium.

Medical follow-up of Persian Gulf War Veterans with severe medically unexplained fatigue: a preliminary study

An important question for researchers interested in long-term consequences of military service is the health outcome of symptomatic Persian Gulf War Veterans. From an original group of 76 Gulf War Veterans who received the diagnosis of severe fatiguing illness, we attempted to get 58 veterans to return to our center for a second evaluation. Thirteen returned. Two had recovered by the time of revisit, but the rest remained ill; however, only one was so ill as to be unable to work. The data suggest that the medical consequences of serving in the Persian Gulf are not transient. The difficulty in getting veterans to return to our center suggests potential problems in the proposed nation-wide longitudinal health outcome study of Persian Gulf War Veterans.

Cognitive functioning in Gulf War Illness

A comprehensive neuropsychological battery was administered to 48 veterans with Gulf War Illness (GWI) characterized by severe fatigue (GV-F) and 39 healthy veterans (GV-H). Subjects were matched on intelligence and did not differ on age, gender, race, and alcohol consumption. Compared to GVs-H, GVs-F were significantly impaired on four tasks: three attention, concentration, information processing tasks and one measure of abstraction and conceptualization. After considering the presence of post-war Axis I psychopathology, GWI remained a significant predictor of cognitive performance on one of the attention, concentration, and information processing tasks and one abstraction and conceptualization measure. Performance on the remaining two attention, concentration, and information processing tasks was only significantly predicted by Axis I psychopathology with post-war onset. The results suggest that Gulf War Illness is associated with some aspects of cognitive dysfunction in Gulf Veterans, over and above the contribution of psychopathology.

Controlled exposures to volatile organic compounds in sensitive groups

Sensitivities to chemicals are characterized by symptoms in multiple organ systems in response to low-level chemical exposures. This paper reviews studies of controlled exposures to odorants and to mixtures of volatile organic compounds. Sensitive subgroups include subjects who met Cullen's 1987 criteria for multiple chemical sensitivity (MCS), Gulf War veterans with chronic fatigue syndrome and chemical sensitivity (CFS/CS), and subjects with specific self-reported sensitivities to methyl terbutyl ether (MTBE) in gasoline (MTBE-sensitive). All studies include comparison of age- and sex-matched healthy controls. Studies of olfaction did not support unusual sensitivity, defined as lower odor thresholds, among MCS subjects; however, a dose-response pattern of symptoms was observed in response to suprathreshold concentrations of phenyl ethyl alcohol. In blinded, controlled exposures to clean air, gasoline, gasoline/11% MTBE, and gasoline/15% MTBE, a threshold effect was observed with MTBE-sensitive subjects reporting significantly increased symptoms to gasoline/15% MTBE exposure. Autonomic arousal (heart and respiration rate; end-tidal CO2) in response to odor of chemical mixtures may mediate symptoms for subjects with generalized chemical sensitivities, but not for those whose sensitivities are confined to specific chemicals. For example, Gulf War veterans with CFS/CS experienced reduced end-tidal CO2 when exposed to diesel fumes, while exposure to MTBE did not produce any psychophysiologic changes in MTBE-sensitive subjects. Controlled olfactory and exposure studies reveal that significant responses can be observed in chemically sensitive subjects even when de-adaptation has not occurred. However, these studies suggest that symptoms are not necessarily accompanied by changes in physiologic arousal. Subject characteristics play a critical role in outcomes.

A controlled short-term exposure study to investigate the odor differences among three different formulations of gasoline

Control subjects (CON) and self-reported methyl tertiary butyl ether (MTBE)-sensitive subjects (SRS) were evaluated to distinguish between the following gasoline blends: gasoline versus gasoline + MTBE (15% MTBE v/v); and gasoline versus gasoline + MTBE + reodorant. The study also investigated the ability of a reodorant to conceal the odor of MTBE in a gasoline mixture. In each of two separate sessions, seven men (four CON, three SRS) and seven women (four CON, three SRS) were asked, in a forced-choice format, to sniff 28 randomized bottle pairs to determine if the odors in each pair were the same or different. Chi-square analyses revealed that, with the exception of one male CON, subjects were unable to distinguish between gasoline and gasoline with MTBE or gasoline with MTBE and the reodorant. Thus, a reodorant is of limited value as an additive which alters the ability of an individual to detect MTBE in a blended gasoline. The results suggest that at the level used in the experiment, no mask would be required to blind a participant from the odor of MTBE if that level is used in a controlled human health effects study of the additive.

Controlled human exposure to methyl tertiary butyl ether in gasoline: symptoms, psychophysiologic and neurobehavioral responses of self-reported sensitive persons

The 1990 Clean Air Act mandated oxygenation of gasoline in regions where carbon monoxide standards were not met. To achieve this standard, methyl tertiary butyl ether (MTBE) was increased to 15% by volume during winter months in many locations. Subsequent to the increase of MTBE in gasoline, commuters reported increases in symptoms such as headache, nausea, and eye, nose, and throat irritation. The present study compared 12 individuals selected based on self-report of symptoms (self-reported sensitives; SRSs) associated with MTBE to 19 controls without self-reported sensitivities. In a double-blind, repeated measures, controlled exposure, subjects were exposed for 15 min to clean air, gasoline, gasoline with 11% MTBE, and gasoline with 15% MTBE. Symptoms, odor ratings, neurobehavioral performance on a task of driving simulation, and psychophysiologic responses (heart and respiration rate, end-tidal CO(2), finger pulse volume, electromyograph, finger temperature) were measured before, during, and immediately after exposure. Relative to controls, SRSs reported significantly more total symptoms when exposed to gasoline with 15% MTBE than when exposed to gasoline with 11% MTBE or to clean air. However, these differences in symptoms were not accompanied by significant differences in neurobehavioral performance or psychophysiologic responses. No significant differences in symptoms or neurobehavioral or psychophysiologic responses were observed when exposure to gasoline with 11% MTBE was compared to clean air or to gasoline. Thus, the present study, although showing increased total symptoms among SRSs when exposed to gasoline with 15% MTBE, did not support a dose-response relationship for MTBE exposure nor the symptom specificity associated with MTBE in epidemiologic studies.

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.

Stressors, personality traits, and coping of Gulf War veterans with chronic fatigue

OBJECTIVES

preliminary surveys of Persian Gulf veterans revealed a significant prevalence of self-reported symptoms consistent with chronic fatigue syndrome (CFS). The purpose of this study was to compare self-reported life stressors, combat, and chemical exposures, personality and coping between Gulf War veterans with CFS and healthy veterans.

METHODS

following a complete physical, psychiatric, and neuropsychological evaluation, 45 healthy veterans, 35 veterans with CFS and co-morbid psychiatric disorder, and 23 veterans with CFS and no co-morbid psychiatric disorder completed questionnaires assessing war and non-war-related life stressors, self-reports of environmental exposure (e.g. oil well fires, pesticides), personality, and coping.

RESULTS

measures of personality, self-reported combat and chemical exposures, and negative coping strategies significantly differentiated healthy veterans from those with CFS.

CONCLUSION

a biopsychosocial model of veterans' illness was supported by the fact that personality, negative coping strategies, life stress after the war, and environmental exposures during the war were significant predictors of veterans' current physical function.

A 37-year-old mechanic with multiple chemical sensitivities

A 37-year-old heating, ventilation, and air-conditioning mechanic developed respiratory, musculoskeletal, and central nervous system symptoms associated with a variety of odorous environmental chemicals. Organic disease was not evident, but the patient was distressed by these symptoms and was at risk for becoming disabled by them. His symptoms fit broadly into the condition recognized as multiple chemical sensitivity. Multiple chemical sensitivity is a diagnostic term for a group of symptoms without demonstrated organic basis. The symptoms are characteristic of dysfunction in multiple organ systems, they increase and decrease according to exposure to low levels of chemical agents in the patient's environment, and they sometimes occur after a distinct environmental change or insult such as an industrial accident or remodeling. Although traditional medical organizations have not agreed on a definition for this syndrome, it is being increasingly recognized and makes up an increasing percentage of the caseload at occupational and environmental medicine clinics. Although there is often dispute about whether the symptoms have a functional or organic basis, an informed approach to evaluation, diagnosis, and management and a careful assessment of impairment, disability, and work relatedness are necessary. Careful exclusion of organic causes is critical, and this should be followed by a judicious approach to coping with symptoms.

Psychiatric diagnoses in Gulf War veterans with fatiguing illness

The purpose of this study was to determine whether Gulf War Illness (GWI) can be explained by the presence of psychiatric disorders as assessed by DSM-III-R. To reduce the heterogeneity amongst Persian Gulf War veterans with GWI (PGV-F), only those were studied who presented with severe fatigue as a major complaint and also fulfilled clinical case definitions for Chronic Fatigue Syndrome, Idiopathic Chronic Fatigue, and/or Multiple Chemical Sensitivity. A total of 95 Registry PGVs were examined; 53 presented with GWI and 42 did not report any post-war health problems (PGV-H). All subjects were assessed for the presence of DSM-III-R Axis I psychiatric disorders. Compared to PGV-Hs, 49% of PGV-Fs had similar post-war psychiatric profiles: either no, or only one, psychiatric disorder was diagnosed. Psychiatric profiles of the remaining 51% of PGV-Fs were significantly different from PGV-Hs in that most of these veterans suffered from multiple post-war psychiatric diagnoses. The presence of psychiatric disorders as assessed by DSM-III-R criteria cannot explain symptoms of Gulf War Illness among all Persian Gulf veterans with severe fatiguing illness.

Prevalence of chronic fatigue and chemical sensitivities in Gulf Registry Veterans

More than 68000 of the 700000 veterans of the Gulf War have become members of the Veteran Affairs' Gulf War Registry. In 1995, we undertook a questionnaire study of the symptoms and medical histories reported by a randomly selected subsample of 1935 of these veterans to characterize their complaints. All results reported were based on questionnaire responses without face-to-face evaluation or physical examinations. Inasmuch as initial registry symptoms overlapped those of Chronic Fatigue Syndrome and Multiple Chemical Sensitivities, we also included standard questions for these syndromes in the questionnaire. A total of 1161 (60%) individuals responded, and there were no major demographic biases; therefore, 15.7% of registry veterans qualified for Chronic Fatigue Syndrome in accordance with the 1994 Centers for Disease Control definition. In addition, 13.1% qualified for multiple chemical sensitivities in accordance with a widely used definition, and 3.3% of the respondents had both conditions. There were no effects of gender, race, branch, duty status (active or reserve), or rank, although Multiple Chemical Sensitivities was somewhat more prevalent in women and African Americans. The data gleaned in this study suggested that the unexplained symptom syndromes of Chronic Fatigue and Multiple Chemical Sensitivities may characterize an appreciable portion of the complaints of those who volunteered for the Veterans Affairs' Gulf War Registry, and further investigation is warranted.

Urinary biomarkers as indicators of renal disease

Using modern technology, minute quantities of LMWP, prostanoids, growth factors, intra-renal and extra-renal enzymes can be measured in urine. Excretory patterns that are characteristic for site and mechanism of renal injury often can be found. It is possible to recognise urinary biomarker patterns that suggest the putative environmental nephrotoxin. Our own studies performed in subjects with low level occupational and environmental exposures in New Jersey confirm the pattern specificity and threshold effects for Cr, Hg and Pb. In addition, we have been able to show that increased NAG and IAP excretion following Pb exposure correlates with current (blood Pb) but not with the cumulative Pb burden (bone Pb). The relatively specific characteristic patterns of biomarker excretion are lost as renal failure progresses. Moreover, renal injury that results in tubular proteinuria may not progress to renal failure. Nevertheless, urine biomarkers can help to establish acceptable levels and identify the need for long term surveillance to ascertain when clinical renal disease may result.

Neuropsychological and stress evaluation of a residential mercury exposure

Residents of a former factory building converted to apartments were exposed to mercury over a 2-year period. The neurobehavioral and emotional health effects of this exposure and subsequent evacuation are presented. Urine mercury levels were measured before (urine1) and 3-10 weeks after evacuation (urine2) of the building, when neurobehavioral and psychological measures were also completed. Performance on neurobehavioral and psychologic measures were compared between subjects above and below the median for urine1 (>=19 microg/g creatinine) and were correlated with urine1 mercury levels. The high urine mercury group made more errors on a test of fine motor function and 84% of the residents reported clinically significant elevations in somatic and psychologic symptoms. Although subclinical tremor from mercury exposure may have affected subtle hand-eye coordination, other tests of motor function were not affected. Therefore, the observation of reduced hand-eye coordination may be due to chance. Significant levels of psychosocial stress were more closely associated with the evacuation necessitated by mercury exposure rather than a direct effect of mercury exposure.

Medical evaluation of Persian Gulf veterans with fatigue and/or chemical sensitivity

The purpose of this study was to determine if Gulf War veterans with complaints of severe fatigue and/or chemical sensitivity (n = 72) fulfill case definitions for chronic fatigue syndrome (CFS) and/or multiple chemical sensitivity (MCS) and to compare the characteristics of those veterans who received a diagnosis of CFS (n = 24) to a group of non-veterans diagnosed with CFS (n = 95). Thirty-three veterans received a diagnosis of CFS with 14 having MCS concurrently; an additional six had MCS but did not fulfill a case definition for CFS. The group of fatigued veterans receiving a diagnosis of CFS was comprised of significantly fewer women and fewer Caucasians than the civilian group, and significantly fewer veterans reported a sudden onset to their illness. Veterans with CFS had a milder form of the illness than their civilian counterparts based on medical examiner assessment of the severity of the symptoms, reported days of reduced activity, and ability to work. Since CFS in veterans seems less severe than that seen in civilians, the prognosis for recovery of veterans with this disorder may be better.

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.

Chemical sensitivity: the scientific literature

This article provides an overview of the scientific literature in which chemically sensitive patients have been directly evaluated. For that purpose, consideration of various case definitions is offered along with summaries of subjects' demographic profiles, exposure characteristics, and symptom profiles across studies. Controlled investigations of chemically sensitive subjects without other organic illnesses are reviewed. To date, psychiatric, personality, cognitive/neurologic, immunologic, and olfactory studies have been conducted comparing subjects with primary chemical sensitivity to various control groups. Thus far, the most consistent finding is that chemically sensitive patients have a higher rate of psychiatric disorders across studies and relative to diverse comparison groups. However, since these studies are cross-sectional, causality cannot be implied. Demonstrating the role of low-level chemical exposure in a controlled environment has yet to be undertaken with this patient group and is crucial to the understanding of this phenomenon.

Chemical sensitivities and the Gulf War: Department of Veterans Affairs Research Center in basic and clinical science studies of environmental hazards

The purpose of the New Jersey Center for Environmental Hazards Research is to define the illness referred to as Persian Gulf Syndrome (PGS). Our preliminary data indicated that more than half of the Persian Gulf Registry (PGR) veterans reported illness characterized by severe fatigue and symptoms consistent with chemical sensitivities. Therefore, our research approach focuses on investigations of veterans with chronic fatigue syndrome (CFS) and multiple chemical sensitivities (MCS). Project 1 is an epidemiological study of 2800 PGR veterans. Symptoms, indices of Chronic Fatigue (CF) and Chemical Sensitivity (CS), and risk factors will be surveyed with mailed questionnaires. Risk factors include demographics, past medical history, psychosocial variables, Gulf War experiences such as prophylactic medication use, occupational and environmental exposures, and pesticide exposures. Symptoms will be clustered to define Gulf War Syndromes. Significant associations between risk factors and these symptom clusters will also be investigated Subjects identified as CF, CS, or both will be recruited into Projects 2 and 3. In Project 2, healthy veterans will be compared to veterans with CF, CS, and CF concurrent with CS. Veterans will undergo four studies: (1) viral-immunological, (2) psychiatric, psychological, behavioral, and neuropsychological, (3) autonomic dysregulation, and (4) marker of P4501A2 induction resulting from exposure to combusting material. The purpose of Project 3 is to test the autonomic, immunologic, neuropsychologic, and psychologic responses of veterans with CS or CF to two stressors: controlled chemical exposure and exercise. CS subjects will undergo chemical exposures in our Controlled Environment Facility (CEF) to assess their biologic and psychologic response to low-level exposure. CF subjects will undergo a maximal treadmill exercise test. Circadian patterns of catecholamines and axillary temperature, viral burden, and cardiovascular and endocrine reactivity will be measured in response to this physical stressor. Project 4 is an animal study evaluating the interaction between stress and pathology/physiology when rats are predisposed to disease by exposure to Soman or to Dioxin. Two strains of rats that differ in stress reactivity will be used to determine the interaction of hereditary factors and chemical exposure.

The assessment of neurobehavioral toxicity: SGOMSEC joint report

Exposure to neurobehavioral toxicants is a problem of international scope. Although many different procedures are available for the assessment of human behavioral function, performance tests are displacing traditional diagnostic tests for ascertaining the consequences of exposure to neurotoxic chemicals. Performance testing includes variables such as attention and concentration, sensory function, motor control, spatial relations, visuomotor coordination, memory, and affect. Special tests have also been devised for evaluating child development. One of the salient needs in these efforts is the construction of databases allowing access to normative data.

Neuropsychological approaches for the detection and evaluation of toxic symptoms

The purpose of this paper is 3-fold: a) to review briefly the neuropsychological tests that have been used to evaluate the effects of neurotoxicants; b) to identify individual factors that may create heightened sensitivity to neurotoxicants; and c) to discuss test parameters that will increase the sensitivity of neuropsychological tests for detecting symptoms in low-level exposure situations. While the body of literature on neurobehavioral toxicology has increased dramatically during the past 10 years, it remains difficult to discern which tests are most effective in detecting behavioral effects even among workers with significant exposures. Few investigators have evaluated the interactions between individual differences, such as gender and psychiatric function, and exposure to neurotoxicants. Detection of behavioral performance decrements among uniquely susceptible populations such as those with sensitivities to low-level exposures (e.g., multiple chemical sensitivities) will require more difficult tests than are frequently used in current neuropsychological test batteries.

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.

Measuring chemical sensitivity prevalence: a questionnaire for population studies

Because no information exists on the prevalence of chemical sensitivity syndromes such as multiple chemical sensitivities, a questionnaire for use in population studies was developed and tested to assess the presence or absence of chemical sensitivity. Seven hundred five individuals attending clinics answered a questionnaire asking whether each of 122 common substances caused symptoms. Results showed that patients with multiple chemical sensitivities and asthma had average total scores that were significantly different from each other and from those of each of the other diagnostic categories. Higher total scores were also reported by female patients. The instrument described here may facilitate meaningful prevalence studies of multiple chemical sensitivities. It will also allow study of chemically induced symptoms in other conditions such as asthma.

Neuropsychology and psychology of MCS

Neurological symptoms are frequently reported by patients with multiple chemical sensitivities (MCS). Methods to compare the psychiatric, personality, and neuropsychological function of patients with MCS, chronic fatigue syndrome (CFS), and normal controls are described. Increased rates of Axis I psychiatric diagnoses are observed in the literature for MCS and CFS subjects relative to controls. Findings on the MMPI-2 and the Toronto Alexithymia Scale reveal profiles consistent with the tendency to report somatic rather than emotional symptoms in response to stress. However, many of the reported somatic symptoms also coincide with those found in neurologic disorders. The overall neuropsychological profile for MCS subjects does not reflect cognitive impairment. Relative to normal controls, the only difference in neuropsychological performance observed is reduced recognition of nontarget designs on a visual memory task. More fruitful areas for future psychological research will include measurement of the interaction between behavioral response styles and attentional processes in cognition, as well as observations under controlled challenge conditions.

Cognitive functioning of patients with chronic fatigue syndrome

Neuropsychological problems are a distressing and frequent component of the symptom complex associated with chronic fatigue syndrome. Objective assessment of these difficulties is essential to understanding the nature of this illness. Results of the studies discussed in this paper suggest that impaired information processing, rather than primary memory dysfunction, may be at the root of the cognitive problems that afflict so many patients with CFS.

Evaluation of chemically sensitive patients

An increasing number of patients have been presenting with multiple symptoms they attribute to low-level chemical exposures, ie, multiple chemical sensitivities (MCS). Although some studies have evaluated such patients, the selection criteria has not been rigorously defined. The present study is the first to use a relatively rigorous definition of MCS to select patients for study. Comprehensive evaluation of medical, psychiatric, neuropsychological, and immunological status of a series of MCS patients is presented. In contrast to previous studies, patients in this study did not have a history of psychiatric disorder. However, some patients were currently depressed. Neuropsychological assessment did not reveal any abnormalities with the exception of one test of verbal memory for which performance was consistently poor relative to the normative sample. No significant immunological abnormalities were noted.

Employee assistance program compliance: impact of contrasting insurance coverage

Employee assistance programs are offered by employers to assist employees with personal problems through professional evaluation of the problem and referral to an appropriate treatment source. Although some research has been conducted to document the effect of these programs on such variables as absenteeism and disciplinary action, little information is available regarding compliance with clinical recommendations, ie, initiating and remaining in prescribed treatment. The present study evaluated the effect of two different rates of insurance coverage for outpatient mental health services offered by two comparable blue-collar organizations. Employees from the organization with a higher rate of payment were significantly more likely to initiate treatment and to remain in treatment longer. This outcome was not accounted for by demographic differences between the groups or by differences in diagnostic categories or treatment approaches. Implications of this finding are discussed as well as the utility of an employee assistance program to prepare employees for treatment.

Understanding stress in hazardous waste workers

In summary, hazardous waste workers comprise a unique occupational group that may be at risk for stress-related illness due to the unusual demands of their work. Occupational health professionals responsible for their surveillance should include surveillance of their mental as well as physical health. When symptoms of stress are evident, both organizational and individual programs may be needed to address these symptoms. Denial of the risks involved should not be promoted, given the potential such denial may have for careless work practices.

Evaluation of a work site relaxation training program using ambulatory blood pressure monitoring

The rising physical, emotional, and economic costs of excess stress in occupational settings have resulted in a proliferation of many work site stress management programs. These programs have attempted to effect reductions in workers' stress by applying standard psychological interventions (ie, muscle relaxation and meditation) to the general work force. The benefits of these interventions for asymptomatic employee populations remain to be established. The purpose of the present study was to evaluate the physical and psychologic effects of an occupational stress management program for asymptomatic hazardous waste workers (N = 66). Both laboratory and ambulatory blood pressure (at home and at work) were monitored, and self-reported psychologic symptoms were measured. The results indicate that the stress management techniques decreased the diastolic blood pressure variability of asymptomatic workers (P less than .001); however, unlike previous studies, no reductions in laboratory blood pressures nor in psychologic symptoms were found. The efficacy of the procedures for asymptomatic employees is questioned and suggestions are made for future research.

Utility of occupational blood pressure screening for the detection of potential hypertension

A potential limiting factor in the detection and control of hypertension has been the assumption that a routine periodic sphygmomanometric blood pressure recording is characteristic of usual blood pressure throughout the activities of daily living. The relationship between routine periodic clinic blood pressure and ambulatory blood pressure was investigated in employed workers. Ambulatory readings were obtained at regular intervals using an automatic self-inflating and recording sphygmomanometer at home and at work. Mean ambulatory systolic and diastolic pressures were significantly higher than clinic pressures, both at home and at work, and in every position except reclining. Eleven of the 113 employees considered normotensive from clinic screening had an average of 46% of their diastolic ambulatory readings greater than or equal to 90. These persons may be considered functionally hypertensive. The authors suggest the need to focus attention on those persons with high-normal clinic blood pressures discovered in workplace screening.

The crisis of rape: a community response

While rape has consistently been viewed as both a personal and familial crisis, there is little evidence that its impact on the community at large has been addressed. The authors describe a program incorporating mental health education and crisis intervention strategies developed in response to a community's reaction to several sexual assaults of children. Program design and implications for replication are also discussed.