Limits...
Sensory and cognitive effects of acute exposure to hydrogen sulfide.

Fiedler N, Kipen H, Ohman-Strickland P, Zhang J, Weisel C, Laumbach R, Kelly-McNeil K, Olejeme K, Lioy P - Environ. Health Perspect. (2008)

Bottom Line: Dose-response reduction in air quality and increases in ratings of odor intensity, irritation, and unpleasantness were observed.No dose-response effect was observed for sensory or cognitive measures.Increased anxiety was significantly related to ratings of irritation due to odor.

View Article: PubMed Central - PubMed

Affiliation: Department of Environmental and Occupational Medicine, UMDNJ-Robert Wood Johnson Medical School, 170 Frelinghuysen Rd., Rm. 210, Piscataway, NJ 08854 USA.. nfiedler@eohsi.rutgers.edu <nfiedler@eohsi.rutgers.edu>

ABSTRACT

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.

Show MeSH

Related in: MedlinePlus

Mean total number of words recalled from List A over 5 trials on the AVLT. Change from baseline to during exposure: p < 0.0001.
© Copyright Policy - public-domain
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC2199294&req=5

f4-ehp0116-000078: Mean total number of words recalled from List A over 5 trials on the AVLT. Change from baseline to during exposure: p < 0.0001.

Mentions: The mixed linear model did not reveal any significant exposure × time interaction for recall of List A after presentation of the interfering List B, recall of List A after a 30-min delay, or recall of List B. A marginal trend was observed for total List A recall (F = 2.51; df = 2, 219; p = 0.08) with a somewhat larger effect of exposure in the 0.05- and 0.5-ppm conditions (Figure 4). Based on the results of the main effects analyses, it appears that although there was no main effect of exposure for any of the AVLT variables: total List A recall (F = 35.43; df = 1, 219; p < 0.0001), recall of List A after presentation of the interfering List B (F = 13.30; df = 1, 219; p = 0.0003), and recall of List A after a 30-min delay (F = 75.88; df = 1, 219; p < 0.0001) were all significantly worse during exposure, illustrating a significant time effect. This time effect appears to be more obvious for the 0.05-ppm and 0.5-ppm conditions relative to the 5-ppm condition. Furthermore, when comparing recall of Trial 1, List A, to recall of List B, no evidence of proactive interference was observed during exposure. That is, subjects either improved or performed similarly in their recall of List B relative to Trial 1 of List A.


Sensory and cognitive effects of acute exposure to hydrogen sulfide.

Fiedler N, Kipen H, Ohman-Strickland P, Zhang J, Weisel C, Laumbach R, Kelly-McNeil K, Olejeme K, Lioy P - Environ. Health Perspect. (2008)

Mean total number of words recalled from List A over 5 trials on the AVLT. Change from baseline to during exposure: p < 0.0001.
© Copyright Policy - public-domain
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2199294&req=5

f4-ehp0116-000078: Mean total number of words recalled from List A over 5 trials on the AVLT. Change from baseline to during exposure: p < 0.0001.
Mentions: The mixed linear model did not reveal any significant exposure × time interaction for recall of List A after presentation of the interfering List B, recall of List A after a 30-min delay, or recall of List B. A marginal trend was observed for total List A recall (F = 2.51; df = 2, 219; p = 0.08) with a somewhat larger effect of exposure in the 0.05- and 0.5-ppm conditions (Figure 4). Based on the results of the main effects analyses, it appears that although there was no main effect of exposure for any of the AVLT variables: total List A recall (F = 35.43; df = 1, 219; p < 0.0001), recall of List A after presentation of the interfering List B (F = 13.30; df = 1, 219; p = 0.0003), and recall of List A after a 30-min delay (F = 75.88; df = 1, 219; p < 0.0001) were all significantly worse during exposure, illustrating a significant time effect. This time effect appears to be more obvious for the 0.05-ppm and 0.5-ppm conditions relative to the 5-ppm condition. Furthermore, when comparing recall of Trial 1, List A, to recall of List B, no evidence of proactive interference was observed during exposure. That is, subjects either improved or performed similarly in their recall of List B relative to Trial 1 of List A.

Bottom Line: Dose-response reduction in air quality and increases in ratings of odor intensity, irritation, and unpleasantness were observed.No dose-response effect was observed for sensory or cognitive measures.Increased anxiety was significantly related to ratings of irritation due to odor.

View Article: PubMed Central - PubMed

Affiliation: Department of Environmental and Occupational Medicine, UMDNJ-Robert Wood Johnson Medical School, 170 Frelinghuysen Rd., Rm. 210, Piscataway, NJ 08854 USA.. nfiedler@eohsi.rutgers.edu <nfiedler@eohsi.rutgers.edu>

ABSTRACT

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.

Show MeSH
Related in: MedlinePlus