Dataset Information

Sickness response symptoms among healthy volunteers after controlled exposures to diesel exhaust and psychological stress.

ABSTRACT:

Background

Interactions between acute exposures to environmental chemical contaminants and psychological stress may be important in situations where they are likely to co-occur, ranging in intensity from daily urban living to participation in war. Modification of symptomatic responses by stress may play a role in medically unexplained symptoms attributed to low-level chemical exposures.

Objectives

We hypothesized that the combination of exposure to diesel exhaust (DE) and acute psychological stress would cause sickness responses in healthy volunteers. Moreover, these responses would be greater in individuals with self-reported prior chemical odor intolerance.

Methods

One hundred adult subjects underwent 1-hr exposures to diluted DE and clean air control. Half of the subjects performed a public-speaking stressor task during the exposures. Subjects completed questionnaires to determine their Chemical Odor Intolerance Index score. Plasma cortisol, end-tidal carbon dioxide, and the severity of 35 symptoms were measured at time points before and after the exposures.

Results

Subjects exposed to DE demonstrated small but statistically significant increases in severity for several symptom categories, including sickness response and upper respiratory, central nervous system, and total symptoms. The psychological stressor did not increase symptom severity independently or via interaction with DE. Subjects with prior self-reported chemical intolerance had more severe sickness response symptoms from DE.

Conclusions

These results suggest that exposure to DE can cause acute sickness response symptoms and that these symptoms are also associated with increased levels of self-reported chemical intolerance. The results did not confirm our hypothesis that an acute stressor would increase sickness response symptom severity during the exposure.

SUBMITTER: Laumbach RJ

PROVIDER: S-EPMC3223003 | biostudies-literature | 2011 Jul

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Sickness response symptoms among healthy volunteers after controlled exposures to diesel exhaust and psychological stress.

Laumbach Robert J RJ Kipen Howard M HM Kelly-McNeil Kathie K Zhang Junfeng J Zhang Lin L Lioy Paul J PJ Ohman-Strickland Pamela P Gong Jing J Kusnecov Alexander A Fiedler Nancy N

Environmental health perspectives 20110217 7

<h4>Background</h4>Interactions between acute exposures to environmental chemical contaminants and psychological stress may be important in situations where they are likely to co-occur, ranging in intensity from daily urban living to participation in war. Modification of symptomatic responses by stress may play a role in medically unexplained symptoms attributed to low-level chemical exposures.<h4>Objectives</h4>We hypothesized that the combination of exposure to diesel exhaust (DE) and acute ps ...[more]

PMID: 21330231

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Project description:The potential effects of combinations of dilute whole diesel exhaust (DE) and ozone (O?), each a common component of ambient airborne pollutant mixtures, on lung function were examined. Healthy young human volunteers were exposed for 2 hr to pollutants while exercising (~50 L/min) intermittently on two consecutive days. Day 1 exposures were either to filtered air, DE (300 ?g/m³), O? (0.300 ppm), or the combination of both pollutants. On Day 2 all exposures were to O? (0.300 ppm), and Day 3 served as a followup observation day. Lung function was assessed by spirometry just prior to, immediately after, and up to 4 hr post-exposure on each exposure day. Functional pulmonary responses to the pollutants were also characterized based on stratification by glutathione S-transferase mu 1 (GSTM1) genotype. On Day 1, exposure to air or DE did not change FEV1 or FVC in the subject population (n?=?15). The co-exposure to O? and DE decreased FEV1 (17.6%) to a greater extent than O? alone (9.9%). To test for synergistic exposure effects, i.e., in a greater than additive fashion, FEV1 changes post individual O? and DE exposures were summed together and compared to the combined DE and O? exposure; the p value was 0.057. On Day 2, subjects who received DE exposure on Day 1 had a larger FEV1 decrement (14.7%) immediately after the O? exposure than the individuals' matched response following a Day 1 air exposure (10.9%). GSTM1 genotype did not affect the magnitude of lung function changes in a significant fashion. These data suggest that altered respiratory responses to the combination of O? and DE exposure can be observed showing a greater than additive manner. In addition, O?-induced lung function decrements are greater with a prior exposure to DE compared to a prior exposure to filtered air. Based on the joint occurrence of these pollutants in the ambient environment, the potential exists for interactions in more than an additive fashion affecting lung physiological processes.

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Dataset Information

Sickness response symptoms among healthy volunteers after controlled exposures to diesel exhaust and psychological stress.

Background

Objectives

Methods

Results

Conclusions

Publications

Sickness response symptoms among healthy volunteers after controlled exposures to diesel exhaust and psychological stress.

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