Heart rate variability in older workers during work under the Threshold Limit Values for heat exposure

2020 ◽  
Vol 63 (9) ◽  
pp. 787-795
Author(s):  
Antonia Kaltsatou ◽  
Andreas D. Flouris ◽  
Christophe L. Herry ◽  
Sean R. Notley ◽  
Michael J. Macartney ◽  
...  
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Older Workers ◽  
Heat Exposure ◽  
Limit Values ◽  
Threshold Limit Values ◽  
Threshold Limit

The recommended Threshold Limit Values for heat exposure fail to maintain body core temperature within safe limits in older working adults

2017 ◽  
Vol 14 (9) ◽  
pp. 703-711 ◽  
Author(s):  
Dallon T. Lamarche ◽  
Robert D. Meade ◽  
Andrew W. D'Souza ◽  
Andreas D. Flouris ◽  
Stephen G. Hardcastle ◽  
...  
Keyword(s):  
Core Temperature ◽  
Heat Exposure ◽  
Body Core Temperature ◽  
Limit Values ◽  
Threshold Limit Values ◽  
Working Adults ◽  
Threshold Limit ◽  
Body Core ◽  
Safe Limits

scholarly journals Cardiac Parasympathetic Withdrawal and Sympathetic Activity: Effect of Heat Exposure on Heart Rate Variability

2021 ◽  
Vol 18 (11) ◽  
pp. 5934
Author(s):  
Oriol Abellán-Aynés ◽  
Pedro Manonelles ◽  
Fernando Alacid
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Environmental Conditions ◽  
Sympathetic Activity ◽  
Heat Exposure ◽  
Repeated Measurements ◽  
Control Group ◽  
Poincaré Plot ◽  
Activity Effect ◽  
And Control

(1) Background: Research on heart rate variability has increased in recent years and the temperature has not been controlled in some studies assessing repeated measurements. This study aimed to analyze how heart rate variability may change based on environmental temperature during measurement depending on parasympathetic and sympathetic activity variations. (2) Methods: A total of 22 volunteers participated in this study divided into an experimental (n = 12) and control group (n = 10). Each participant was assessed randomly under two different environmental conditions for the experimental group (19 °C and 35 °C) and two identical environmental conditions for the control group (19 °C). During the procedure, heart rate variability measurements were carried out for 10 min. (3) Results: Significantly changes were observed for time and frequency domains as well as Poincaré plot variables after heat exposure (p < 0.05). These findings were not observed in the control group, whose conditions between measurements did not change. (4) Conclusions: The reduction of heart rate variability due to exposure to hot conditions appears to be produced mostly by a parasympathetic withdrawal rather than a sympathetic activation. Therefore, if consecutive measurements have to be carried out, these should always be done under the same temperature conditions.

Seven days of hot water heat acclimation does not modulate the change in heart rate variability during passive heat exposure

2020 ◽  
Author(s):  
Philippe Gendron ◽  
Hugo Gravel ◽  
Hadiatou Barry ◽  
Daniel Gagnon
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
High Frequency ◽  
Water Immersion ◽  
Heat Exposure ◽  
Thermal Strain ◽  
Heat Acclimation ◽  
Hot Water ◽  
Frequency Range ◽  
The Mean

We examined if the change in heart rate variability (HRV) during passive heat exposure is modified by hot water heat acclimation (HA). Sixteen healthy adults (28 ± 5 years, 5 females/11 males) underwent heat exposure in a water-perfused suit, pre and post 7 days of HA (60 minutes at rectal temperature ≥38.6°C). During passive heat exposure, heart rate (HR), the standard deviation of NN intervals (SDNN), the square root of the mean squared differences of successive NN intervals (RMSSD) and the power in the high frequency range (HF) were measured. No difference in HR (P=0.22), SDNN (P=0.87), RMSSD (P=0.79) and HF (P=0.23) was observed at baseline. The increase in HR (pre-HA: 43 ± 10, post-HA: 42 ± 9 bpm, P=0.57) and the decrease of SDNN (pre-HA: -54.1 ± 41.0, post-HA: -52.2 ± 36.8 ms, P=0.85), RMSSD (pre-HA: -70.8 ± 49.5, post-HA: -72.7 ± 50.4 ms, P=0.91) and HF (pre-HA: -28.0 ± 14.5, post-HA: -23.2 ± 17.1%, P=0.27) were not different between experimental visits at fixed increases in esophageal temperature. These results suggest that 7 consecutive days of hot water HA does not modify the change in HRV indices during passive heat exposure. Novelty bullets: - It remains unclear if heat acclimation alters the change in heart rate variability that occurs during passive heat exposure. - At matched levels of thermal strain, 7 consecutive days of hot water immersion did not modulate the change in indices of heart rate variability during passive heat exposure.

Particle Size-Selective Sampling in Establishing Threshold Limit Values

1986 ◽  
Vol 1 (3) ◽  
pp. 138-144 ◽  
Author(s):  
Bruce Owen Stuart ◽  
Paul J. Lioy ◽  
Robert F. Phalen
Keyword(s):  
Particle Size ◽  
Limit Values ◽  
Threshold Limit Values ◽  
Selective Sampling ◽  
Threshold Limit
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